Articles | Volume 14, issue 5
https://doi.org/10.5194/amt-14-3319-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-14-3319-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
06 May 2021
Research article |
| 06 May 2021
| 06 May 2021
Consistency of total column ozone measurements between the Brewer and Dobson spectroradiometers of the LKO Arosa and PMOD/WRC Davos
Julian Gröbner
CORRESPONDING AUTHOR
Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf, Switzerland
Herbert Schill
Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf, Switzerland
Luca Egli
Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf, Switzerland
René Stübi
Meteoswiss, Payerne, Switzerland
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Atmos. Meas. Tech., 17, 2277–2294, https://doi.org/10.5194/amt-17-2277-2024, https://doi.org/10.5194/amt-17-2277-2024, 2024
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Antonio Fernando Almansa, África Barreto, Natalia Kouremeti, Ramiro González, Akriti Masoom, Carlos Toledano, Julian Gröbner, Rosa Delia García, Yenny González, Stelios Kazadzis, Stéphane Victori, Óscar Álvarez, Fabrice Maupin, Virgilio Carreño, Victoria Eugenia Cachorro, and Emilio Cuevas
Atmos. Meas. Tech., 17, 659–675, https://doi.org/10.5194/amt-17-659-2024, https://doi.org/10.5194/amt-17-659-2024, 2024
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Atmos. Meas. Tech., 16, 4861–4884, https://doi.org/10.5194/amt-16-4861-2023, https://doi.org/10.5194/amt-16-4861-2023, 2023
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Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-188, https://doi.org/10.5194/amt-2023-188, 2023
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We present a fast an easy method to incorporate clouds from satellite imagery into a model for calculating surface UV index maps in near-real time. To judge the quality of the model, we compare our results to measurements from ground based detectors. We discuss in detail where variations in either of the values come from and why satellite and ground values might not necessarily be comparable in every situation.
Julian Gröbner, Natalia Kouremeti, Gregor Hülsen, Ralf Zuber, Mario Ribnitzky, Saulius Nevas, Peter Sperfeld, Kerstin Schwind, Philipp Schneider, Stelios Kazadzis, África Barreto, Tom Gardiner, Kavitha Mottungan, David Medland, and Marc Coleman
Atmos. Meas. Tech., 16, 4667–4680, https://doi.org/10.5194/amt-16-4667-2023, https://doi.org/10.5194/amt-16-4667-2023, 2023
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Spectral solar irradiance measurements traceable to the International System of Units (SI) allow for intercomparability between instruments and for their validation according to metrological standards. Here we also validate and reduce the uncertainties of the top-of-atmosphere TSIS-1 Hybrid Solar Reference Spectrum (HSRS). The management of large networks, e.g. AERONET or GAW-PFR, will benefit from reducing logistical overhead, improving their resilience and achieving metrological traceability.
Luca Egli, Julian Gröbner, Herbert Schill, and Eliane Maillard Barras
Atmos. Meas. Tech., 16, 2889–2902, https://doi.org/10.5194/amt-16-2889-2023, https://doi.org/10.5194/amt-16-2889-2023, 2023
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Xiaoyi Zhao, Vitali Fioletov, Alberto Redondas, Julian Gröbner, Luca Egli, Franz Zeilinger, Javier López-Solano, Alberto Berjón Arroyo, James Kerr, Eliane Maillard Barras, Herman Smit, Michael Brohart, Reno Sit, Akira Ogyu, Ihab Abboud, and Sum Chi Lee
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The Brewer ozone spectrophotometer is one of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW)'s standard ozone monitoring instruments since the 1980s. This work is aimed at obtaining answers to (1) why Brewer primary calibration work can only be performed at certain sites (e.g., Izaña and MLO) and (2) what is needed to assure the equivalence of calibration quality from different sites.
Bruce W. Forgan, Julian Gröbner, and Ibrahim Reda
Atmos. Meas. Tech., 16, 727–743, https://doi.org/10.5194/amt-16-727-2023, https://doi.org/10.5194/amt-16-727-2023, 2023
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Atmos. Meas. Tech., 15, 5667–5680, https://doi.org/10.5194/amt-15-5667-2022, https://doi.org/10.5194/amt-15-5667-2022, 2022
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Marek Šmíd, Geiland Porrovecchio, Jiří Tesař, Tim Burnitt, Luca Egli, Julian Grőbner, Petr Linduška, and Martin Staněk
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Atmos. Meas. Tech., 13, 6999–7024, https://doi.org/10.5194/amt-13-6999-2020, https://doi.org/10.5194/amt-13-6999-2020, 2020
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areas were used for the validation of the TROPOMI surface ultraviolet (UV) radiation product. For most sites 60 %–80 % of TROPOMI data was within ± 20 % of ground-based data.
Ilias Fountoulakis, Henri Diémoz, Anna Maria Siani, Gregor Hülsen, and Julian Gröbner
Earth Syst. Sci. Data, 12, 2787–2810, https://doi.org/10.5194/essd-12-2787-2020, https://doi.org/10.5194/essd-12-2787-2020, 2020
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In this study we discuss the procedures and the technical aspects which ensure the high quality of the measurements of the global solar ultraviolet (UV) irradiance performed by a Bentham spectroradiometer located at Aosta–Saint-Christophe (north-western Alps), Italy. This particular instrument is the reference for the Aosta Valley UV monitoring network, which is the first UV monitoring network in Italy. The final spectra constitute one of the most accurate datasets globally.
Christine Aebi, Julian Gröbner, Stelios Kazadzis, Laurent Vuilleumier, Antonis Gkikas, and Niklaus Kämpfer
Atmos. Meas. Tech., 13, 907–923, https://doi.org/10.5194/amt-13-907-2020, https://doi.org/10.5194/amt-13-907-2020, 2020
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Clouds are one of the largest sources of uncertainties in climate models. The current study estimates the cloud optical thickness (COT), the effective droplet radius and the single scattering albedo of stratus–altostratus and cirrus–cirrostratus clouds in Payerne, Switzerland, by combining ground- and satellite-based measurements and radiative transfer models. The estimated values are thereafter compared with data retrieved from other methods. The mean COT is distinct for different seasons.
Stephan Nyeki, Stefan Wacker, Christine Aebi, Julian Gröbner, Giovanni Martucci, and Laurent Vuilleumier
Atmos. Chem. Phys., 19, 13227–13241, https://doi.org/10.5194/acp-19-13227-2019, https://doi.org/10.5194/acp-19-13227-2019, 2019
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The trends of meteorological parameters and surface downward shortwave radiation (DSR) and downward longwave radiation (DLR) were analysed at four stations (between 370 and 3580 m a. s. l.) in Switzerland for the 1996–2015 period. Trends in DSR and DLR were positive during cloudy as well as clear conditions. The trend due to the influence of clouds decreased in magnitude, which implies a reduction in cloud cover and/or a change towards a different cloud type over the four Swiss sites.
Emilio Cuevas, Pedro Miguel Romero-Campos, Natalia Kouremeti, Stelios Kazadzis, Petri Räisänen, Rosa Delia García, Africa Barreto, Carmen Guirado-Fuentes, Ramón Ramos, Carlos Toledano, Fernando Almansa, and Julian Gröbner
Atmos. Meas. Tech., 12, 4309–4337, https://doi.org/10.5194/amt-12-4309-2019, https://doi.org/10.5194/amt-12-4309-2019, 2019
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A comprehensive comparison of more than 70 000 synchronous 1 min aerosol optical depth (AOD) data from 3 Global Atmosphere Watch precision filter radiometers (GAW-PFR) and 15 Aerosol Robotic Network Cimel radiometers (AERONET-Cimel) was performed for the four
nearwavelengths (380, 440, 500 and 870 nm) in the period 2005–2015. The goal of this study is to assess whether their long term AOD data are comparable and consistent.
Christine Aebi, Julian Gröbner, and Niklaus Kämpfer
Atmos. Meas. Tech., 11, 5549–5563, https://doi.org/10.5194/amt-11-5549-2018, https://doi.org/10.5194/amt-11-5549-2018, 2018
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A newly developed hemispherical thermal infrared cloud camera (IRCCAM) is presented. The IRCCAM allows automatic cloud detection during the day and at night-time. The cloud fraction determined from the IRCCAM is compared with the cloud fraction determined from other instruments over a time period of 2 years. The IRCCAM has an agreement of +/- 2 oktas cloud fraction in 90 % of the data compared to other instruments. There are no significant differences between seasons or different times of day.
Carlos Toledano, Ramiro González, David Fuertes, Emilio Cuevas, Thomas F. Eck, Stelios Kazadzis, Natalia Kouremeti, Julian Gröbner, Philippe Goloub, Luc Blarel, Roberto Román, África Barreto, Alberto Berjón, Brent N. Holben, and Victoria E. Cachorro
Atmos. Chem. Phys., 18, 14555–14567, https://doi.org/10.5194/acp-18-14555-2018, https://doi.org/10.5194/acp-18-14555-2018, 2018
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Most of the ground-based radiometric networks have their reference instruments and/or calibrate them at Mauna Loa or Izaña. The suitability of these high-mountain stations for absolute radiometric calibrations is investigated with the support of 20 years of first-class Sun photometer data from the AERONET and GAW-PFR networks. We analyze the number of calibration days at each site in a climatological sense and investigate the uncertainty of the calibrations based on long-term statistics.
Kaisa Lakkala, Antti Arola, Julian Gröbner, Sergio Fabian León-Luis, Alberto Redondas, Stelios Kazadzis, Tomi Karppinen, Juha Matti Karhu, Luca Egli, Anu Heikkilä, Tapani Koskela, Antonio Serrano, and José Manuel Vilaplana
Atmos. Meas. Tech., 11, 5167–5180, https://doi.org/10.5194/amt-11-5167-2018, https://doi.org/10.5194/amt-11-5167-2018, 2018
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The performance of the cosine error correction method for correcting spectral UV measurements of the Brewer spectroradiometer was studied. The correction depends on the sky radiation distribution, which can change during one spectral scan. The results showed that the correction varied between 4 and 14 %, and that the relative differences between the reference and the Brewer diminished by 10 %. The method is applicable to other instruments as long as the required input parameters are available.
Alberto Redondas, Virgilio Carreño, Sergio F. León-Luis, Bentorey Hernández-Cruz, Javier López-Solano, Juan J. Rodriguez-Franco, José M. Vilaplana, Julian Gröbner, John Rimmer, Alkiviadis F. Bais, Vladimir Savastiouk, Juan R. Moreta, Lamine Boulkelia, Nis Jepsen, Keith M. Wilson, Vadim Shirotov, and Tomi Karppinen
Atmos. Chem. Phys., 18, 9441–9455, https://doi.org/10.5194/acp-18-9441-2018, https://doi.org/10.5194/acp-18-9441-2018, 2018
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This work shows an overview of the total ozone comparison of the Brewer instrument during the 10th RBCC-E campaign in a joint effort with the EUBREWNET COST 1207 action. The status of the network after 2 years of calibration shows 16 out of the 21 participating Brewer instruments (76 %) agreed within better than ±1 %, and 10 instruments (50 %) agreed within better than ±0.5 %. After applying the final calibration and the stray light correction all working instruments agreed at the ±0.5 % level.
Anna Vaskuri, Petri Kärhä, Luca Egli, Julian Gröbner, and Erkki Ikonen
Atmos. Meas. Tech., 11, 3595–3610, https://doi.org/10.5194/amt-11-3595-2018, https://doi.org/10.5194/amt-11-3595-2018, 2018
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In this work, we introduce a Monte Carlo uncertainty analysis that takes into account possible systematic spectral deviations in the atmospheric full spectrum ozone retrieval method. Accounting for possible systematic spectral deviations in the spectral data is important since they produce larger total ozone column uncertainties than uncorrelated noise-like variations that traditional uncertainty estimations predict.
Rosa Delia García, Africa Barreto, Emilio Cuevas, Julian Gröbner, Omaira Elena García, Angel Gómez-Peláez, Pedro Miguel Romero-Campos, Alberto Redondas, Victoria Eugenia Cachorro, and Ramon Ramos
Geosci. Model Dev., 11, 2139–2152, https://doi.org/10.5194/gmd-11-2139-2018, https://doi.org/10.5194/gmd-11-2139-2018, 2018
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A 7-year comparison study between measured and simulated longwave
downward radiation under cloud-free conditions has been performed at BSRN Izaña. Results show an excellent agreement with a mean bias (simulated–measured) less than 1.1 % and RMSE less than 1 %, which are within the instrumental error (2 %).
Daniela Meloni, Alcide di Sarra, Gérard Brogniez, Cyrielle Denjean, Lorenzo De Silvestri, Tatiana Di Iorio, Paola Formenti, José L. Gómez-Amo, Julian Gröbner, Natalia Kouremeti, Giuliano Liuzzi, Marc Mallet, Giandomenico Pace, and Damiano M. Sferlazzo
Atmos. Chem. Phys., 18, 4377–4401, https://doi.org/10.5194/acp-18-4377-2018, https://doi.org/10.5194/acp-18-4377-2018, 2018
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This study examines how different aerosol optical properties determine the dust longwave radiative effects at the surface, in the atmosphere and at the top of the atmosphere, based on the combination of remote sensing and in situ observations from the ground, from airborne sensors, and from space, by means of radiative transfer modelling. The closure experiment is based on longwave irradiances and spectral brightness temperatures measured during the 2013 ChArMEx–ADRIMED campaign at Lampedusa.
Christof Janssen, Hadj Elandaloussi, and Julian Gröbner
Atmos. Meas. Tech., 11, 1707–1723, https://doi.org/10.5194/amt-11-1707-2018, https://doi.org/10.5194/amt-11-1707-2018, 2018
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Monitoring ozone layer recovery at a rate of few percent per decade requires dedicated instrumentation and spectroscopic data of the highest quality. Highly accurate absorption cross sections of ozone are rare, especially in the important UV region between 300 and 340 nm. Our measurement provides the first reference point with permil level of accuracy in this range. Interestingly, our value is lower than currently used data. This might resolve an inconsistency between UV and IR measurements.
Javier López-Solano, Alberto Redondas, Thomas Carlund, Juan J. Rodriguez-Franco, Henri Diémoz, Sergio F. León-Luis, Bentorey Hernández-Cruz, Carmen Guirado-Fuentes, Natalia Kouremeti, Julian Gröbner, Stelios Kazadzis, Virgilio Carreño, Alberto Berjón, Daniel Santana-Díaz, Manuel Rodríguez-Valido, Veerle De Bock, Juan R. Moreta, John Rimmer, Andrew R. D. Smedley, Lamine Boulkelia, Nis Jepsen, Paul Eriksen, Alkiviadis F. Bais, Vadim Shirotov, José M. Vilaplana, Keith M. Wilson, and Tomi Karppinen
Atmos. Chem. Phys., 18, 3885–3902, https://doi.org/10.5194/acp-18-3885-2018, https://doi.org/10.5194/acp-18-3885-2018, 2018
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The European Brewer Network (EUBREWNET, COST Action ES1207) is comprised of close to 50 instruments and currently provides near-real-time ozone and UV data. Aerosols also play key role in the Earth–atmosphere system and introduce a large uncertainty into our understanding of climate change. In this work we describe and validate a method to incorporate the measurement of aerosols in EUBREWNET. We find that this Brewer network can provide reliable aerosol data across Europe in the UV range.
Stelios Kazadzis, Natalia Kouremeti, Henri Diémoz, Julian Gröbner, Bruce W. Forgan, Monica Campanelli, Victor Estellés, Kathleen Lantz, Joseph Michalsky, Thomas Carlund, Emilio Cuevas, Carlos Toledano, Ralf Becker, Stephan Nyeki, Panagiotis G. Kosmopoulos, Viktar Tatsiankou, Laurent Vuilleumier, Frederick M. Denn, Nozomu Ohkawara, Osamu Ijima, Philippe Goloub, Panagiotis I. Raptis, Michael Milner, Klaus Behrens, Africa Barreto, Giovanni Martucci, Emiel Hall, James Wendell, Bryan E. Fabbri, and Christoph Wehrli
Atmos. Chem. Phys., 18, 3185–3201, https://doi.org/10.5194/acp-18-3185-2018, https://doi.org/10.5194/acp-18-3185-2018, 2018
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Aerosol optical depth measured from ground-based sun photometers is the most important parameter for studying the changes in the Earth's radiation balance due to aerosols. Representatives for various sun photometer types belonging to individual institutions or international aerosol networks gather every 5 years, for 3 weeks, in Davos, Switzerland, in order to compare their aeorosol optical depth retrievals. This work presents the results of the latest (fourth) filter radiometer intercomparison.
Panagiotis-Ioannis Raptis, Stelios Kazadzis, Julian Gröbner, Natalia Kouremeti, Lionel Doppler, Ralf Becker, and Constantinos Helmis
Atmos. Meas. Tech., 11, 1143–1157, https://doi.org/10.5194/amt-11-1143-2018, https://doi.org/10.5194/amt-11-1143-2018, 2018
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The purpose of this work is to retrieve integrated water vapour using spectral measurements from Precision Solar Spectroradiometer (PSR). Two different approaches were developed one using single-channel direct sun irradiance measurements, and the second one integrating at a certain spectral region. The results of the spectral approach are closer to the retrievals of non-photometric techniques (GPS, microwave radiometer and radiosondes), suggesting this method provide more accurate IWV product.
Stelios Kazadzis, Natalia Kouremeti, Stephan Nyeki, Julian Gröbner, and Christoph Wehrli
Geosci. Instrum. Method. Data Syst., 7, 39–53, https://doi.org/10.5194/gi-7-39-2018, https://doi.org/10.5194/gi-7-39-2018, 2018
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The World Optical Depth Research Calibration Center (WORCC) has been established after the recommendations of WMO for calibration of aerosol optical depth (AOD) -related sun photometers. WORCC is mandated to initiate homogenization activities among different AOD networks and to run a network (GAW-PFR) of sun photometers. To calibrate such instruments aiming at low measurement uncertainties the quality assurance, quality control and a basic hierarchy have to be defined and followed.
Christine Aebi, Julian Gröbner, Niklaus Kämpfer, and Laurent Vuilleumier
Atmos. Meas. Tech., 10, 4587–4600, https://doi.org/10.5194/amt-10-4587-2017, https://doi.org/10.5194/amt-10-4587-2017, 2017
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The current study analyses the cloud radiative effect during the daytime depending on cloud fraction and cloud type at two stations in Switzerland over a time period of 3–5 years. Information about fractional cloud coverage and cloud type is retrieved from images taken by visible all-sky cameras. Cloud cover, cloud type and other atmospheric parameters have an influence on the magnitude of the longwave cloud effect as well as on the shortwave.
René Stübi, Herbert Schill, Jörg Klausen, Laurent Vuilleumier, Julian Gröbner, Luca Egli, and Dominique Ruffieux
Atmos. Meas. Tech., 10, 4479–4490, https://doi.org/10.5194/amt-10-4479-2017, https://doi.org/10.5194/amt-10-4479-2017, 2017
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Long-term measurement series are the pillars of all climate change analysis. The Arosa total ozone series is the world's longest record, starting in 1926. To secure the future of these measurements, it is foreseen to move the instruments in Davos. To ascertain that the series will not be affected by this change, a multiyear campaign of parallel measurements on both sites has been done. The analysis of these data is presented and it is concluded that no discernible difference can be identified.
Julian Gröbner, Ingo Kröger, Luca Egli, Gregor Hülsen, Stefan Riechelmann, and Peter Sperfeld
Atmos. Meas. Tech., 10, 3375–3383, https://doi.org/10.5194/amt-10-3375-2017, https://doi.org/10.5194/amt-10-3375-2017, 2017
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We have produced a benchmark high-resolution solar extraterrestrial spectrum from ground-based measurements of direct solar irradiance in the wavelength range 300 to 500 nm. This spectrum can be used for model calculations and for validating solar spectra measured in space. The metrological traceability of this solar spectrum to the International System of Units (SI) is assured by an unbroken chain of calibrations traceable to the primary spectral irradiance standard of PTB.
Stephan Nyeki, Stefan Wacker, Julian Gröbner, Wolfgang Finsterle, and Martin Wild
Atmos. Meas. Tech., 10, 3057–3071, https://doi.org/10.5194/amt-10-3057-2017, https://doi.org/10.5194/amt-10-3057-2017, 2017
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A large number of radiometers used to measure solar and terrestrial broadband radiation are traceable to World Standard Groups at PMOD/WRC in Davos, Switzerland. A small correction of each group may be required in the future, and this study examines the methods and implications of this on data sets collected at four remote baseline stations since the 1990s. The goal is to develop a better estimate of the solar and terrestrial radiation budget at the Earth's surface.
Thomas Carlund, Natalia Kouremeti, Stelios Kazadzis, and Julian Gröbner
Atmos. Meas. Tech., 10, 905–923, https://doi.org/10.5194/amt-10-905-2017, https://doi.org/10.5194/amt-10-905-2017, 2017
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Aerosols play an important role in atmospheric processes. Aerosol optical depth is the most common measure of columnar aerosol load. We present a sunphotometer called UVPFR that is able to measure aerosol optical depth in the ultraviolet range, including the calibration, characterization and validation of the instrument/measurements. The instrument will serve as a reference on the intercalibration of Brewer spectrophotometers that are also able to measure aerosol optical depth in the UV region.
Christos S. Zerefos, Kostas Eleftheratos, John Kapsomenakis, Stavros Solomos, Antje Inness, Dimitris Balis, Alberto Redondas, Henk Eskes, Marc Allaart, Vassilis Amiridis, Arne Dahlback, Veerle De Bock, Henri Diémoz, Ronny Engelmann, Paul Eriksen, Vitali Fioletov, Julian Gröbner, Anu Heikkilä, Irina Petropavlovskikh, Janusz Jarosławski, Weine Josefsson, Tomi Karppinen, Ulf Köhler, Charoula Meleti, Christos Repapis, John Rimmer, Vladimir Savinykh, Vadim Shirotov, Anna Maria Siani, Andrew R. D. Smedley, Martin Stanek, and René Stübi
Atmos. Chem. Phys., 17, 551–574, https://doi.org/10.5194/acp-17-551-2017, https://doi.org/10.5194/acp-17-551-2017, 2017
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The paper makes a convincing case that the Brewer network is capable of detecting enhanced SO2 columns, as observed, e.g., after volcanic eruptions. For this reason, large volcanic eruptions of the past decade have been used to detect and forecast SO2 plumes of volcanic origin using the Brewer and other ground-based networks, aided by satellite, trajectory analysis calculations and modelling.
Luca Egli, Julian Gröbner, Gregor Hülsen, Luciano Bachmann, Mario Blumthaler, Jimmy Dubard, Marina Khazova, Richard Kift, Kees Hoogendijk, Antonio Serrano, Andrew Smedley, and José-Manuel Vilaplana
Atmos. Meas. Tech., 9, 1553–1567, https://doi.org/10.5194/amt-9-1553-2016, https://doi.org/10.5194/amt-9-1553-2016, 2016
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Array spectroradiometers are small, light, robust and cost-effective instruments, and are increasingly used for atmospheric measurements. The quality of array spectroradiometers is assessed for the reliable quantification of ultraviolet radiation (UV) in order to monitor the exposure of UV radiation to human health. The study shows that reliable UV measurements with these instruments are limited for observations around noon and show large biases in the morning and evening.
África Barreto, Emilio Cuevas, María-José Granados-Muñoz, Lucas Alados-Arboledas, Pedro M. Romero, Julian Gröbner, Natalia Kouremeti, Antonio F. Almansa, Tom Stone, Carlos Toledano, Roberto Román, Mikhail Sorokin, Brent Holben, Marius Canini, and Margarita Yela
Atmos. Meas. Tech., 9, 631–654, https://doi.org/10.5194/amt-9-631-2016, https://doi.org/10.5194/amt-9-631-2016, 2016
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This paper presents the new photometer CE318-T, able to perform daytime and
night-time photometric measurements using the sun and the moon as light
sources. This new device permits a complete cycle of diurnal aerosol and water vapour measurements to be extracted, valuable to enhance atmospheric monitoring. We have also highlighted the ability of this new device to capture short-term atmospheric variations, critical for climate studies.
M. Lothon, F. Lohou, D. Pino, F. Couvreux, E. R. Pardyjak, J. Reuder, J. Vilà-Guerau de Arellano, P Durand, O. Hartogensis, D. Legain, P. Augustin, B. Gioli, D. H. Lenschow, I. Faloona, C. Yagüe, D. C. Alexander, W. M. Angevine, E Bargain, J. Barrié, E. Bazile, Y. Bezombes, E. Blay-Carreras, A. van de Boer, J. L. Boichard, A. Bourdon, A. Butet, B. Campistron, O. de Coster, J. Cuxart, A. Dabas, C. Darbieu, K. Deboudt, H. Delbarre, S. Derrien, P. Flament, M. Fourmentin, A. Garai, F. Gibert, A. Graf, J. Groebner, F. Guichard, M. A. Jiménez, M. Jonassen, A. van den Kroonenberg, V. Magliulo, S. Martin, D. Martinez, L. Mastrorillo, A. F. Moene, F. Molinos, E. Moulin, H. P. Pietersen, B. Piguet, E. Pique, C. Román-Cascón, C. Rufin-Soler, F. Saïd, M. Sastre-Marugán, Y. Seity, G. J. Steeneveld, P. Toscano, O. Traullé, D. Tzanos, S. Wacker, N. Wildmann, and A. Zaldei
Atmos. Chem. Phys., 14, 10931–10960, https://doi.org/10.5194/acp-14-10931-2014, https://doi.org/10.5194/acp-14-10931-2014, 2014
S. Kazadzis, I. Veselovskii, V. Amiridis, J. Gröbner, A. Suvorina, S. Nyeki, E. Gerasopoulos, N. Kouremeti, M. Taylor, A. Tsekeri, and C. Wehrli
Atmos. Meas. Tech., 7, 2013–2025, https://doi.org/10.5194/amt-7-2013-2014, https://doi.org/10.5194/amt-7-2013-2014, 2014
A. Stenke, C. R. Hoyle, B. Luo, E. Rozanov, J. Gröbner, L. Maag, S. Brönnimann, and T. Peter
Atmos. Chem. Phys., 13, 9713–9729, https://doi.org/10.5194/acp-13-9713-2013, https://doi.org/10.5194/acp-13-9713-2013, 2013
T. Egorova, E. Rozanov, J. Gröbner, M. Hauser, and W. Schmutz
Atmos. Chem. Phys., 13, 3811–3823, https://doi.org/10.5194/acp-13-3811-2013, https://doi.org/10.5194/acp-13-3811-2013, 2013
Ilias Fountoulakis, Kyriaki Papachristopoulou, Stelios Kazadzis, Gregor Hülsen, Julian Gröbner, Ioannis-Panagiotis Raptis, Dimitra Kouklaki, Akriti Masoom, Charalampos Kontoes, and Christos S. Zerefos
EGUsphere, https://doi.org/10.5194/egusphere-2024-2964, https://doi.org/10.5194/egusphere-2024-2964, 2024
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The UVIOS2 model has been evaluated at Davos, Switzerland during the UVCIII campaign. The accuracy in the modelled UV indices has been assessed for different combinations of model inputs. A good overall agreement between UVIOS2 and the world reference spectroradiometer QASUME was found (average ratio of ~1 between the modelled and measured UV index), although the variability in the ratio can be large under cloudy conditions.
Monica Campanelli, Victor Estellés, Gaurav Kumar, Teruyuki Nakajima, Masahiro Momoi, Julian Gröbner, Stelios Kazadzis, Natalia Kouremeti, Angelos Karanikolas, Africa Barreto, Saulius Nevas, Kerstin Schwind, Philipp Schneider, Iiro Harju, Petri Kärhä, Henri Diémoz, Rei Kudo, Akihiro Uchiyama, Akihiro Yamazaki, Anna Maria Iannarelli, Gabriele Mevi, Annalisa Di Bernardino, and Stefano Casadio
Atmos. Meas. Tech., 17, 5029–5050, https://doi.org/10.5194/amt-17-5029-2024, https://doi.org/10.5194/amt-17-5029-2024, 2024
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To retrieve columnar aerosol properties from sun photometers, some calibration factors are needed. The on-site calibrations, performed as frequently as possible to monitor changes in the machine conditions, allow operators to track and evaluate the calibration status on a continuous basis, reducing the data gaps incurred by the periodic shipments for performing centralized calibrations. The performance of the on-site calibration procedures was evaluated, providing very good results.
Karl Voglmeier, Voltaire A. Velazco, Luca Egli, Julian Gröbner, Alberto Redondas, and Wolfgang Steinbrecht
Atmos. Meas. Tech., 17, 2277–2294, https://doi.org/10.5194/amt-17-2277-2024, https://doi.org/10.5194/amt-17-2277-2024, 2024
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Comparison between total ozone column (TOC) measurements from ground-based Dobson and Brewer spectrophotometers generally reveals seasonally varying differences of a few percent. This study recommends a new TOC retrieval approach, which effectively eliminates these seasonally varying differences by applying new ozone absorption cross sections, appropriate slit functions for the Dobson instrument, and climatological values for the effective ozone temperature.
Antonio Fernando Almansa, África Barreto, Natalia Kouremeti, Ramiro González, Akriti Masoom, Carlos Toledano, Julian Gröbner, Rosa Delia García, Yenny González, Stelios Kazadzis, Stéphane Victori, Óscar Álvarez, Fabrice Maupin, Virgilio Carreño, Victoria Eugenia Cachorro, and Emilio Cuevas
Atmos. Meas. Tech., 17, 659–675, https://doi.org/10.5194/amt-17-659-2024, https://doi.org/10.5194/amt-17-659-2024, 2024
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This paper applies sun photometer synergies to improve calibration transference between different sun photometers and also enhance their quality assurance and quality control. We have validated this technique using different instrumentation, the WMO-GAW and NASA-AERONET references, under different aerosol regimes using the standard Langley calibration method as a reference.
Óscar Alvárez, África Barreto, Omaira E. García, Frank Hase, Rosa D. García, Julian Gröbner, Sergio F. León-Luis, Eliezer Sepúlveda, Virgilio Carreño, Antonio Alcántara, Ramón Ramos, A. Fernando Almansa, Stelios Kazadzis, Noémie Taquet, Carlos Toledano, and Emilio Cuevas
Atmos. Meas. Tech., 16, 4861–4884, https://doi.org/10.5194/amt-16-4861-2023, https://doi.org/10.5194/amt-16-4861-2023, 2023
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In this work, we have extended the capabilities of a portable Fourier transform infrared (FTIR) instrument, which was originally designed to provide high-quality greenhouse gas monitoring within COCCON (COllaborative Carbon Column Observing Network). The extension allows the spectrometer to now also provide coincidentally column-integrated aerosol information. This addition of a reference instrument to a global network will be utilised to enhance our understanding of atmospheric chemistry.
Verena Schenzinger, Axel Kreuter, Barbara Klotz, Michael Schwarzmann, and Julian Gröbner
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-188, https://doi.org/10.5194/amt-2023-188, 2023
Revised manuscript not accepted
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We present a fast an easy method to incorporate clouds from satellite imagery into a model for calculating surface UV index maps in near-real time. To judge the quality of the model, we compare our results to measurements from ground based detectors. We discuss in detail where variations in either of the values come from and why satellite and ground values might not necessarily be comparable in every situation.
Julian Gröbner, Natalia Kouremeti, Gregor Hülsen, Ralf Zuber, Mario Ribnitzky, Saulius Nevas, Peter Sperfeld, Kerstin Schwind, Philipp Schneider, Stelios Kazadzis, África Barreto, Tom Gardiner, Kavitha Mottungan, David Medland, and Marc Coleman
Atmos. Meas. Tech., 16, 4667–4680, https://doi.org/10.5194/amt-16-4667-2023, https://doi.org/10.5194/amt-16-4667-2023, 2023
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Spectral solar irradiance measurements traceable to the International System of Units (SI) allow for intercomparability between instruments and for their validation according to metrological standards. Here we also validate and reduce the uncertainties of the top-of-atmosphere TSIS-1 Hybrid Solar Reference Spectrum (HSRS). The management of large networks, e.g. AERONET or GAW-PFR, will benefit from reducing logistical overhead, improving their resilience and achieving metrological traceability.
Luca Egli, Julian Gröbner, Herbert Schill, and Eliane Maillard Barras
Atmos. Meas. Tech., 16, 2889–2902, https://doi.org/10.5194/amt-16-2889-2023, https://doi.org/10.5194/amt-16-2889-2023, 2023
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This paper introduces a new method to retrieve total column ozone with spectral ground-based measurements from a novel array spectroradiometer. Total column ozone estimates using the small, cost-effective, and robust instrument and the new retrieval method are compared with other co-located total column ozone instruments. The comparison shows that the new system performs similarly to other well-established instruments, which require substantially more maintenance than the system introduced here.
Xiaoyi Zhao, Vitali Fioletov, Alberto Redondas, Julian Gröbner, Luca Egli, Franz Zeilinger, Javier López-Solano, Alberto Berjón Arroyo, James Kerr, Eliane Maillard Barras, Herman Smit, Michael Brohart, Reno Sit, Akira Ogyu, Ihab Abboud, and Sum Chi Lee
Atmos. Meas. Tech., 16, 2273–2295, https://doi.org/10.5194/amt-16-2273-2023, https://doi.org/10.5194/amt-16-2273-2023, 2023
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The Brewer ozone spectrophotometer is one of the World Meteorological Organization (WMO) Global Atmosphere Watch (GAW)'s standard ozone monitoring instruments since the 1980s. This work is aimed at obtaining answers to (1) why Brewer primary calibration work can only be performed at certain sites (e.g., Izaña and MLO) and (2) what is needed to assure the equivalence of calibration quality from different sites.
Bruce W. Forgan, Julian Gröbner, and Ibrahim Reda
Atmos. Meas. Tech., 16, 727–743, https://doi.org/10.5194/amt-16-727-2023, https://doi.org/10.5194/amt-16-727-2023, 2023
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This paper investigates the Absolute Cavity Pyrgeometer (ACP) and its use in measuring atmospheric terrestrial irradiances traceable to the standard system of units (SI). This work fits into the objective of the Expert Team on Radiation References, established by the World Meteorological Organization (WMO), to develop and validate instrumentation that can be used as reference instruments for terrestrial radiation measurements.
Eliane Maillard Barras, Alexander Haefele, René Stübi, Achille Jouberton, Herbert Schill, Irina Petropavlovskikh, Koji Miyagawa, Martin Stanek, and Lucien Froidevaux
Atmos. Chem. Phys., 22, 14283–14302, https://doi.org/10.5194/acp-22-14283-2022, https://doi.org/10.5194/acp-22-14283-2022, 2022
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Intercomparisons of three Dobson and three Brewer spectrophotometers at Arosa/Davos, Switzerland, are used for the homogenization of the longest Umkehr ozone profiles time series worldwide. Dynamic linear modeling (DLM) reveals a significant positive trend after 2004 in the upper stratosphere, a persistent negative trend between 25 and 30 km in the middle stratosphere, and a negative trend at 20 km in the lower stratosphere, with different levels of significance depending on the dataset.
Angelos Karanikolas, Natalia Kouremeti, Julian Gröbner, Luca Egli, and Stelios Kazadzis
Atmos. Meas. Tech., 15, 5667–5680, https://doi.org/10.5194/amt-15-5667-2022, https://doi.org/10.5194/amt-15-5667-2022, 2022
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The aim of this work is to investigate the limitations of calculating long-term trends of a parameter that quantifies the overall effect of atmospheric aerosols on the solar radiation. A main finding is that even instruments with good agreement between their observations can show significantly different linear trends. By calculating time-varying trends, the trend agreement is shown to improve. We also show that different methods of trend estimation can result in significant trend differences.
Sophie Godin-Beekmann, Niramson Azouz, Viktoria F. Sofieva, Daan Hubert, Irina Petropavlovskikh, Peter Effertz, Gérard Ancellet, Doug A. Degenstein, Daniel Zawada, Lucien Froidevaux, Stacey Frith, Jeannette Wild, Sean Davis, Wolfgang Steinbrecht, Thierry Leblanc, Richard Querel, Kleareti Tourpali, Robert Damadeo, Eliane Maillard Barras, René Stübi, Corinne Vigouroux, Carlo Arosio, Gerald Nedoluha, Ian Boyd, Roeland Van Malderen, Emmanuel Mahieu, Dan Smale, and Ralf Sussmann
Atmos. Chem. Phys., 22, 11657–11673, https://doi.org/10.5194/acp-22-11657-2022, https://doi.org/10.5194/acp-22-11657-2022, 2022
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An updated evaluation up to 2020 of stratospheric ozone profile long-term trends at extrapolar latitudes based on satellite and ground-based records is presented. Ozone increase in the upper stratosphere is confirmed, with significant trends at most latitudes. In this altitude region, a very good agreement is found with trends derived from chemistry–climate model simulations. Observed and modelled trends diverge in the lower stratosphere, but the differences are non-significant.
Nora Mettig, Mark Weber, Alexei Rozanov, John P. Burrows, Pepijn Veefkind, Anne M. Thompson, Ryan M. Stauffer, Thierry Leblanc, Gerard Ancellet, Michael J. Newchurch, Shi Kuang, Rigel Kivi, Matthew B. Tully, Roeland Van Malderen, Ankie Piters, Bogumil Kois, René Stübi, and Pavla Skrivankova
Atmos. Meas. Tech., 15, 2955–2978, https://doi.org/10.5194/amt-15-2955-2022, https://doi.org/10.5194/amt-15-2955-2022, 2022
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Vertical ozone profiles from combined spectral measurements in the UV and IR spectral ranges were retrieved by using data from TROPOMI/S5P and CrIS/Suomi-NPP. The vertical resolution and accuracy of the ozone profiles are improved by combining both wavelength ranges compared to retrievals limited to UV or IR spectral data only. The advancement of our TOPAS algorithm for combined measurements is required because in the UV-only retrieval the vertical resolution in the troposphere is very limited.
Luca Egli, Julian Gröbner, Gregor Hülsen, Herbert Schill, and René Stübi
Atmos. Meas. Tech., 15, 1917–1930, https://doi.org/10.5194/amt-15-1917-2022, https://doi.org/10.5194/amt-15-1917-2022, 2022
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This study presents traceable total column ozone retrievals from direct solar spectral irradiance measurements. The retrieved ozone does not require any field calibration with a reference instrument as it is required for other operational network instruments such as Brewer or Dobson. Total column ozone can be retrieved with a traceable overall standard uncertainty of less than 0.8 % indicating a benchmark uncertainty for total column ozone measurements.
René Stübi, Herbert Schill, Jörg Klausen, Eliane Maillard Barras, and Alexander Haefele
Atmos. Meas. Tech., 14, 5757–5769, https://doi.org/10.5194/amt-14-5757-2021, https://doi.org/10.5194/amt-14-5757-2021, 2021
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In the first half of the 20th century, Prof. Dobson developed an instrument to measure the ozone column. Around 50 of these Dobson instruments, manufactured in the second half of the 20th century, are still used today to monitor the state of the ozone layer. Started in 1926, the Arosa series was, until recently, based on manually operated Dobsons. To ensure its future operation, a fully automated version of the Dobson has been developed. This well-working automated system is described here.
Panagiotis G. Kosmopoulos, Stelios Kazadzis, Alois W. Schmalwieser, Panagiotis I. Raptis, Kyriakoula Papachristopoulou, Ilias Fountoulakis, Akriti Masoom, Alkiviadis F. Bais, Julia Bilbao, Mario Blumthaler, Axel Kreuter, Anna Maria Siani, Kostas Eleftheratos, Chrysanthi Topaloglou, Julian Gröbner, Bjørn Johnsen, Tove M. Svendby, Jose Manuel Vilaplana, Lionel Doppler, Ann R. Webb, Marina Khazova, Hugo De Backer, Anu Heikkilä, Kaisa Lakkala, Janusz Jaroslawski, Charikleia Meleti, Henri Diémoz, Gregor Hülsen, Barbara Klotz, John Rimmer, and Charalampos Kontoes
Atmos. Meas. Tech., 14, 5657–5699, https://doi.org/10.5194/amt-14-5657-2021, https://doi.org/10.5194/amt-14-5657-2021, 2021
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Large-scale retrievals of the ultraviolet index (UVI) in real time by exploiting the modern Earth observation data and techniques are capable of forming operational early warning systems that raise awareness among citizens of the health implications of high UVI doses. In this direction a novel UVI operating system, the so-called UVIOS, was introduced for massive outputs, while its performance was tested against ground-based measurements revealing a dependence on the input quality and resolution.
Ralf Zuber, Ulf Köhler, Luca Egli, Mario Ribnitzky, Wolfgang Steinbrecht, and Julian Gröbner
Atmos. Meas. Tech., 14, 4915–4928, https://doi.org/10.5194/amt-14-4915-2021, https://doi.org/10.5194/amt-14-4915-2021, 2021
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We validated two BTS-based systems in a longer-term TOC analysis in the 2019/2020 campaign at Hohenpeißenberg and Davos. The results showed a deviation of the BTS-Solar to Brewers of < 0.1 % with a k = 2 of < 1.5 %. Koherent showed a deviation of 1.7 % with a k = 2 of 2.7 %. Resultingly, the BTS-Solar performance is comparable to Brewers in Hohenpeißenberg. Koherent shows a seasonal variation in Davos due to the sensitivity of its TOC retrieval algorithm to stratospheric temperature.
René Stübi, Herbert Schill, Eliane Maillard Barras, Jörg Klausen, and Alexander Haefele
Atmos. Meas. Tech., 14, 4203–4217, https://doi.org/10.5194/amt-14-4203-2021, https://doi.org/10.5194/amt-14-4203-2021, 2021
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Total ozone column has been measured since 1926 in the Swiss Alps station Arosa. These worldwide series are based on Dobson sun spectrophotometers. To assure the continuity of these series, a two-stage project was realized at MeteoSwiss: first, Dobson instruments were automated, and then parallel measurements between Arosa and a nearby site in Davos were carried out. The analysis of the data of the manual-to-automated transition and coincident data between the two sites are presented here.
Marek Šmíd, Geiland Porrovecchio, Jiří Tesař, Tim Burnitt, Luca Egli, Julian Grőbner, Petr Linduška, and Martin Staněk
Atmos. Meas. Tech., 14, 3573–3582, https://doi.org/10.5194/amt-14-3573-2021, https://doi.org/10.5194/amt-14-3573-2021, 2021
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We designed and developed a tuneable and portable radiation source (TuPS) to provide a reference wavelength scale, with a bandwidth of emitted radiation of 0.13 nm and uncertainty in wavelength of 0.02 nm. TuPS was successfully used for the in-field characterization of 14 Dobson spectrophotometers in campaigns in Europe. The line spread functions of Dobsons measured by TuPS in conjunction with the cross-sections from IUP improves the consistency between the Dobson and Brewer from 3 % to 1 %.
Kaisa Lakkala, Jukka Kujanpää, Colette Brogniez, Nicolas Henriot, Antti Arola, Margit Aun, Frédérique Auriol, Alkiviadis F. Bais, Germar Bernhard, Veerle De Bock, Maxime Catalfamo, Christine Deroo, Henri Diémoz, Luca Egli, Jean-Baptiste Forestier, Ilias Fountoulakis, Katerina Garane, Rosa Delia Garcia, Julian Gröbner, Seppo Hassinen, Anu Heikkilä, Stuart Henderson, Gregor Hülsen, Bjørn Johnsen, Niilo Kalakoski, Angelos Karanikolas, Tomi Karppinen, Kevin Lamy, Sergio F. León-Luis, Anders V. Lindfors, Jean-Marc Metzger, Fanny Minvielle, Harel B. Muskatel, Thierry Portafaix, Alberto Redondas, Ricardo Sanchez, Anna Maria Siani, Tove Svendby, and Johanna Tamminen
Atmos. Meas. Tech., 13, 6999–7024, https://doi.org/10.5194/amt-13-6999-2020, https://doi.org/10.5194/amt-13-6999-2020, 2020
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The TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor (S5P) satellite was launched on 13 October 2017 to provide the atmospheric composition for atmosphere and climate research. Ground-based data from 25 sites located in Arctic, subarctic, temperate, equatorial and Antarctic
areas were used for the validation of the TROPOMI surface ultraviolet (UV) radiation product. For most sites 60 %–80 % of TROPOMI data was within ± 20 % of ground-based data.
Ilias Fountoulakis, Henri Diémoz, Anna Maria Siani, Gregor Hülsen, and Julian Gröbner
Earth Syst. Sci. Data, 12, 2787–2810, https://doi.org/10.5194/essd-12-2787-2020, https://doi.org/10.5194/essd-12-2787-2020, 2020
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In this study we discuss the procedures and the technical aspects which ensure the high quality of the measurements of the global solar ultraviolet (UV) irradiance performed by a Bentham spectroradiometer located at Aosta–Saint-Christophe (north-western Alps), Italy. This particular instrument is the reference for the Aosta Valley UV monitoring network, which is the first UV monitoring network in Italy. The final spectra constitute one of the most accurate datasets globally.
Holger Vömel, Herman G. J. Smit, David Tarasick, Bryan Johnson, Samuel J. Oltmans, Henry Selkirk, Anne M. Thompson, Ryan M. Stauffer, Jacquelyn C. Witte, Jonathan Davies, Roeland van Malderen, Gary A. Morris, Tatsumi Nakano, and Rene Stübi
Atmos. Meas. Tech., 13, 5667–5680, https://doi.org/10.5194/amt-13-5667-2020, https://doi.org/10.5194/amt-13-5667-2020, 2020
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The time response of electrochemical concentration cell (ECC) ozonesondes points to at least two distinct reaction pathways with time constants of approximately 20 s and 25 min. Properly considering these time constants eliminates the need for a poorly defined "background" and allows reducing ad hoc corrections based on laboratory tests. This reduces the uncertainty of ECC ozonesonde measurements throughout the profile and especially in regions of low ozone and strong gradients of ozone.
Christine Aebi, Julian Gröbner, Stelios Kazadzis, Laurent Vuilleumier, Antonis Gkikas, and Niklaus Kämpfer
Atmos. Meas. Tech., 13, 907–923, https://doi.org/10.5194/amt-13-907-2020, https://doi.org/10.5194/amt-13-907-2020, 2020
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Clouds are one of the largest sources of uncertainties in climate models. The current study estimates the cloud optical thickness (COT), the effective droplet radius and the single scattering albedo of stratus–altostratus and cirrus–cirrostratus clouds in Payerne, Switzerland, by combining ground- and satellite-based measurements and radiative transfer models. The estimated values are thereafter compared with data retrieved from other methods. The mean COT is distinct for different seasons.
Stephan Nyeki, Stefan Wacker, Christine Aebi, Julian Gröbner, Giovanni Martucci, and Laurent Vuilleumier
Atmos. Chem. Phys., 19, 13227–13241, https://doi.org/10.5194/acp-19-13227-2019, https://doi.org/10.5194/acp-19-13227-2019, 2019
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The trends of meteorological parameters and surface downward shortwave radiation (DSR) and downward longwave radiation (DLR) were analysed at four stations (between 370 and 3580 m a. s. l.) in Switzerland for the 1996–2015 period. Trends in DSR and DLR were positive during cloudy as well as clear conditions. The trend due to the influence of clouds decreased in magnitude, which implies a reduction in cloud cover and/or a change towards a different cloud type over the four Swiss sites.
Emilio Cuevas, Pedro Miguel Romero-Campos, Natalia Kouremeti, Stelios Kazadzis, Petri Räisänen, Rosa Delia García, Africa Barreto, Carmen Guirado-Fuentes, Ramón Ramos, Carlos Toledano, Fernando Almansa, and Julian Gröbner
Atmos. Meas. Tech., 12, 4309–4337, https://doi.org/10.5194/amt-12-4309-2019, https://doi.org/10.5194/amt-12-4309-2019, 2019
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A comprehensive comparison of more than 70 000 synchronous 1 min aerosol optical depth (AOD) data from 3 Global Atmosphere Watch precision filter radiometers (GAW-PFR) and 15 Aerosol Robotic Network Cimel radiometers (AERONET-Cimel) was performed for the four
nearwavelengths (380, 440, 500 and 870 nm) in the period 2005–2015. The goal of this study is to assess whether their long term AOD data are comparable and consistent.
Jean-Pierre Pommereau, Florence Goutail, René Stübi, and Geir Braathen
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2019-211, https://doi.org/10.5194/amt-2019-211, 2019
Publication in AMT not foreseen
Leonie Bernet, Thomas von Clarmann, Sophie Godin-Beekmann, Gérard Ancellet, Eliane Maillard Barras, René Stübi, Wolfgang Steinbrecht, Niklaus Kämpfer, and Klemens Hocke
Atmos. Chem. Phys., 19, 4289–4309, https://doi.org/10.5194/acp-19-4289-2019, https://doi.org/10.5194/acp-19-4289-2019, 2019
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After severe ozone depletion, upper stratospheric ozone has started to recover in recent years. However, stratospheric ozone trends from various data sets still show differences. To partly explain such differences, we investigate how the trends are affected by different factors, for example, anomalies in the data. We show how trend estimates can be improved by considering such anomalies and present updated stratospheric ozone trends from ground data measured in central Europe.
Christine Aebi, Julian Gröbner, and Niklaus Kämpfer
Atmos. Meas. Tech., 11, 5549–5563, https://doi.org/10.5194/amt-11-5549-2018, https://doi.org/10.5194/amt-11-5549-2018, 2018
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A newly developed hemispherical thermal infrared cloud camera (IRCCAM) is presented. The IRCCAM allows automatic cloud detection during the day and at night-time. The cloud fraction determined from the IRCCAM is compared with the cloud fraction determined from other instruments over a time period of 2 years. The IRCCAM has an agreement of +/- 2 oktas cloud fraction in 90 % of the data compared to other instruments. There are no significant differences between seasons or different times of day.
Carlos Toledano, Ramiro González, David Fuertes, Emilio Cuevas, Thomas F. Eck, Stelios Kazadzis, Natalia Kouremeti, Julian Gröbner, Philippe Goloub, Luc Blarel, Roberto Román, África Barreto, Alberto Berjón, Brent N. Holben, and Victoria E. Cachorro
Atmos. Chem. Phys., 18, 14555–14567, https://doi.org/10.5194/acp-18-14555-2018, https://doi.org/10.5194/acp-18-14555-2018, 2018
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Most of the ground-based radiometric networks have their reference instruments and/or calibrate them at Mauna Loa or Izaña. The suitability of these high-mountain stations for absolute radiometric calibrations is investigated with the support of 20 years of first-class Sun photometer data from the AERONET and GAW-PFR networks. We analyze the number of calibration days at each site in a climatological sense and investigate the uncertainty of the calibrations based on long-term statistics.
Kaisa Lakkala, Antti Arola, Julian Gröbner, Sergio Fabian León-Luis, Alberto Redondas, Stelios Kazadzis, Tomi Karppinen, Juha Matti Karhu, Luca Egli, Anu Heikkilä, Tapani Koskela, Antonio Serrano, and José Manuel Vilaplana
Atmos. Meas. Tech., 11, 5167–5180, https://doi.org/10.5194/amt-11-5167-2018, https://doi.org/10.5194/amt-11-5167-2018, 2018
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The performance of the cosine error correction method for correcting spectral UV measurements of the Brewer spectroradiometer was studied. The correction depends on the sky radiation distribution, which can change during one spectral scan. The results showed that the correction varied between 4 and 14 %, and that the relative differences between the reference and the Brewer diminished by 10 %. The method is applicable to other instruments as long as the required input parameters are available.
Alberto Redondas, Virgilio Carreño, Sergio F. León-Luis, Bentorey Hernández-Cruz, Javier López-Solano, Juan J. Rodriguez-Franco, José M. Vilaplana, Julian Gröbner, John Rimmer, Alkiviadis F. Bais, Vladimir Savastiouk, Juan R. Moreta, Lamine Boulkelia, Nis Jepsen, Keith M. Wilson, Vadim Shirotov, and Tomi Karppinen
Atmos. Chem. Phys., 18, 9441–9455, https://doi.org/10.5194/acp-18-9441-2018, https://doi.org/10.5194/acp-18-9441-2018, 2018
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This work shows an overview of the total ozone comparison of the Brewer instrument during the 10th RBCC-E campaign in a joint effort with the EUBREWNET COST 1207 action. The status of the network after 2 years of calibration shows 16 out of the 21 participating Brewer instruments (76 %) agreed within better than ±1 %, and 10 instruments (50 %) agreed within better than ±0.5 %. After applying the final calibration and the stray light correction all working instruments agreed at the ±0.5 % level.
Arno Keppens, Jean-Christopher Lambert, José Granville, Daan Hubert, Tijl Verhoelst, Steven Compernolle, Barry Latter, Brian Kerridge, Richard Siddans, Anne Boynard, Juliette Hadji-Lazaro, Cathy Clerbaux, Catherine Wespes, Daniel R. Hurtmans, Pierre-François Coheur, Jacob C. A. van Peet, Ronald J van der A, Katerina Garane, Maria Elissavet Koukouli, Dimitris S. Balis, Andy Delcloo, Rigel Kivi, Réné Stübi, Sophie Godin-Beekmann, Michel Van Roozendael, and Claus Zehner
Atmos. Meas. Tech., 11, 3769–3800, https://doi.org/10.5194/amt-11-3769-2018, https://doi.org/10.5194/amt-11-3769-2018, 2018
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This work, performed at the Royal Belgian Institute for Space Aeronomy and the second in a series of four Ozone_cci papers, reports for the first time on data content studies, information content studies, and comparisons with co-located ground-based reference observations for all 13 nadir ozone profile data products that are part of the Climate Research Data Package (CRDP) on atmospheric ozone of the European Space Agency's Climate Change Initiative.
Anna Vaskuri, Petri Kärhä, Luca Egli, Julian Gröbner, and Erkki Ikonen
Atmos. Meas. Tech., 11, 3595–3610, https://doi.org/10.5194/amt-11-3595-2018, https://doi.org/10.5194/amt-11-3595-2018, 2018
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In this work, we introduce a Monte Carlo uncertainty analysis that takes into account possible systematic spectral deviations in the atmospheric full spectrum ozone retrieval method. Accounting for possible systematic spectral deviations in the spectral data is important since they produce larger total ozone column uncertainties than uncorrelated noise-like variations that traditional uncertainty estimations predict.
Rosa Delia García, Africa Barreto, Emilio Cuevas, Julian Gröbner, Omaira Elena García, Angel Gómez-Peláez, Pedro Miguel Romero-Campos, Alberto Redondas, Victoria Eugenia Cachorro, and Ramon Ramos
Geosci. Model Dev., 11, 2139–2152, https://doi.org/10.5194/gmd-11-2139-2018, https://doi.org/10.5194/gmd-11-2139-2018, 2018
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A 7-year comparison study between measured and simulated longwave
downward radiation under cloud-free conditions has been performed at BSRN Izaña. Results show an excellent agreement with a mean bias (simulated–measured) less than 1.1 % and RMSE less than 1 %, which are within the instrumental error (2 %).
Johannes Staehelin, Pierre Viatte, Rene Stübi, Fiona Tummon, and Thomas Peter
Atmos. Chem. Phys., 18, 6567–6584, https://doi.org/10.5194/acp-18-6567-2018, https://doi.org/10.5194/acp-18-6567-2018, 2018
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In 1926, total ozone series started in Arosa (Switzerland). Since the mid-1970s ozone is measured to document the effects of anthropogenic ozone-depleting substances (ODSs). ODSs peaked around the mid-1990s, resulting from the Montreal Protocol (1987) and its enforcement. Chemical ozone depletion stopped worsening around the mid-1990s but the large variability complicates demonstrations of the success of the protocol and the effect of ongoing climate change still requires continuous measurement.
Daniela Meloni, Alcide di Sarra, Gérard Brogniez, Cyrielle Denjean, Lorenzo De Silvestri, Tatiana Di Iorio, Paola Formenti, José L. Gómez-Amo, Julian Gröbner, Natalia Kouremeti, Giuliano Liuzzi, Marc Mallet, Giandomenico Pace, and Damiano M. Sferlazzo
Atmos. Chem. Phys., 18, 4377–4401, https://doi.org/10.5194/acp-18-4377-2018, https://doi.org/10.5194/acp-18-4377-2018, 2018
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This study examines how different aerosol optical properties determine the dust longwave radiative effects at the surface, in the atmosphere and at the top of the atmosphere, based on the combination of remote sensing and in situ observations from the ground, from airborne sensors, and from space, by means of radiative transfer modelling. The closure experiment is based on longwave irradiances and spectral brightness temperatures measured during the 2013 ChArMEx–ADRIMED campaign at Lampedusa.
Christof Janssen, Hadj Elandaloussi, and Julian Gröbner
Atmos. Meas. Tech., 11, 1707–1723, https://doi.org/10.5194/amt-11-1707-2018, https://doi.org/10.5194/amt-11-1707-2018, 2018
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Monitoring ozone layer recovery at a rate of few percent per decade requires dedicated instrumentation and spectroscopic data of the highest quality. Highly accurate absorption cross sections of ozone are rare, especially in the important UV region between 300 and 340 nm. Our measurement provides the first reference point with permil level of accuracy in this range. Interestingly, our value is lower than currently used data. This might resolve an inconsistency between UV and IR measurements.
Javier López-Solano, Alberto Redondas, Thomas Carlund, Juan J. Rodriguez-Franco, Henri Diémoz, Sergio F. León-Luis, Bentorey Hernández-Cruz, Carmen Guirado-Fuentes, Natalia Kouremeti, Julian Gröbner, Stelios Kazadzis, Virgilio Carreño, Alberto Berjón, Daniel Santana-Díaz, Manuel Rodríguez-Valido, Veerle De Bock, Juan R. Moreta, John Rimmer, Andrew R. D. Smedley, Lamine Boulkelia, Nis Jepsen, Paul Eriksen, Alkiviadis F. Bais, Vadim Shirotov, José M. Vilaplana, Keith M. Wilson, and Tomi Karppinen
Atmos. Chem. Phys., 18, 3885–3902, https://doi.org/10.5194/acp-18-3885-2018, https://doi.org/10.5194/acp-18-3885-2018, 2018
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The European Brewer Network (EUBREWNET, COST Action ES1207) is comprised of close to 50 instruments and currently provides near-real-time ozone and UV data. Aerosols also play key role in the Earth–atmosphere system and introduce a large uncertainty into our understanding of climate change. In this work we describe and validate a method to incorporate the measurement of aerosols in EUBREWNET. We find that this Brewer network can provide reliable aerosol data across Europe in the UV range.
Stelios Kazadzis, Natalia Kouremeti, Henri Diémoz, Julian Gröbner, Bruce W. Forgan, Monica Campanelli, Victor Estellés, Kathleen Lantz, Joseph Michalsky, Thomas Carlund, Emilio Cuevas, Carlos Toledano, Ralf Becker, Stephan Nyeki, Panagiotis G. Kosmopoulos, Viktar Tatsiankou, Laurent Vuilleumier, Frederick M. Denn, Nozomu Ohkawara, Osamu Ijima, Philippe Goloub, Panagiotis I. Raptis, Michael Milner, Klaus Behrens, Africa Barreto, Giovanni Martucci, Emiel Hall, James Wendell, Bryan E. Fabbri, and Christoph Wehrli
Atmos. Chem. Phys., 18, 3185–3201, https://doi.org/10.5194/acp-18-3185-2018, https://doi.org/10.5194/acp-18-3185-2018, 2018
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Aerosol optical depth measured from ground-based sun photometers is the most important parameter for studying the changes in the Earth's radiation balance due to aerosols. Representatives for various sun photometer types belonging to individual institutions or international aerosol networks gather every 5 years, for 3 weeks, in Davos, Switzerland, in order to compare their aeorosol optical depth retrievals. This work presents the results of the latest (fourth) filter radiometer intercomparison.
Panagiotis-Ioannis Raptis, Stelios Kazadzis, Julian Gröbner, Natalia Kouremeti, Lionel Doppler, Ralf Becker, and Constantinos Helmis
Atmos. Meas. Tech., 11, 1143–1157, https://doi.org/10.5194/amt-11-1143-2018, https://doi.org/10.5194/amt-11-1143-2018, 2018
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The purpose of this work is to retrieve integrated water vapour using spectral measurements from Precision Solar Spectroradiometer (PSR). Two different approaches were developed one using single-channel direct sun irradiance measurements, and the second one integrating at a certain spectral region. The results of the spectral approach are closer to the retrievals of non-photometric techniques (GPS, microwave radiometer and radiosondes), suggesting this method provide more accurate IWV product.
William T. Ball, Justin Alsing, Daniel J. Mortlock, Johannes Staehelin, Joanna D. Haigh, Thomas Peter, Fiona Tummon, Rene Stübi, Andrea Stenke, John Anderson, Adam Bourassa, Sean M. Davis, Doug Degenstein, Stacey Frith, Lucien Froidevaux, Chris Roth, Viktoria Sofieva, Ray Wang, Jeannette Wild, Pengfei Yu, Jerald R. Ziemke, and Eugene V. Rozanov
Atmos. Chem. Phys., 18, 1379–1394, https://doi.org/10.5194/acp-18-1379-2018, https://doi.org/10.5194/acp-18-1379-2018, 2018
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Using a robust analysis, with artefact-corrected ozone data, we confirm upper stratospheric ozone is recovering following the Montreal Protocol, but that lower stratospheric ozone (50° S–50° N) has continued to decrease since 1998, and the ozone layer as a whole (60° S–60° N) may be lower today than in 1998. No change in total column ozone may be due to increasing tropospheric ozone. State-of-the-art models do not reproduce lower stratospheric ozone decreases.
Stelios Kazadzis, Natalia Kouremeti, Stephan Nyeki, Julian Gröbner, and Christoph Wehrli
Geosci. Instrum. Method. Data Syst., 7, 39–53, https://doi.org/10.5194/gi-7-39-2018, https://doi.org/10.5194/gi-7-39-2018, 2018
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The World Optical Depth Research Calibration Center (WORCC) has been established after the recommendations of WMO for calibration of aerosol optical depth (AOD) -related sun photometers. WORCC is mandated to initiate homogenization activities among different AOD networks and to run a network (GAW-PFR) of sun photometers. To calibrate such instruments aiming at low measurement uncertainties the quality assurance, quality control and a basic hierarchy have to be defined and followed.
Christine Aebi, Julian Gröbner, Niklaus Kämpfer, and Laurent Vuilleumier
Atmos. Meas. Tech., 10, 4587–4600, https://doi.org/10.5194/amt-10-4587-2017, https://doi.org/10.5194/amt-10-4587-2017, 2017
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The current study analyses the cloud radiative effect during the daytime depending on cloud fraction and cloud type at two stations in Switzerland over a time period of 3–5 years. Information about fractional cloud coverage and cloud type is retrieved from images taken by visible all-sky cameras. Cloud cover, cloud type and other atmospheric parameters have an influence on the magnitude of the longwave cloud effect as well as on the shortwave.
René Stübi, Herbert Schill, Jörg Klausen, Laurent Vuilleumier, Julian Gröbner, Luca Egli, and Dominique Ruffieux
Atmos. Meas. Tech., 10, 4479–4490, https://doi.org/10.5194/amt-10-4479-2017, https://doi.org/10.5194/amt-10-4479-2017, 2017
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Long-term measurement series are the pillars of all climate change analysis. The Arosa total ozone series is the world's longest record, starting in 1926. To secure the future of these measurements, it is foreseen to move the instruments in Davos. To ascertain that the series will not be affected by this change, a multiyear campaign of parallel measurements on both sites has been done. The analysis of these data is presented and it is concluded that no discernible difference can be identified.
Julian Gröbner, Ingo Kröger, Luca Egli, Gregor Hülsen, Stefan Riechelmann, and Peter Sperfeld
Atmos. Meas. Tech., 10, 3375–3383, https://doi.org/10.5194/amt-10-3375-2017, https://doi.org/10.5194/amt-10-3375-2017, 2017
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We have produced a benchmark high-resolution solar extraterrestrial spectrum from ground-based measurements of direct solar irradiance in the wavelength range 300 to 500 nm. This spectrum can be used for model calculations and for validating solar spectra measured in space. The metrological traceability of this solar spectrum to the International System of Units (SI) is assured by an unbroken chain of calibrations traceable to the primary spectral irradiance standard of PTB.
Stephan Nyeki, Stefan Wacker, Julian Gröbner, Wolfgang Finsterle, and Martin Wild
Atmos. Meas. Tech., 10, 3057–3071, https://doi.org/10.5194/amt-10-3057-2017, https://doi.org/10.5194/amt-10-3057-2017, 2017
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A large number of radiometers used to measure solar and terrestrial broadband radiation are traceable to World Standard Groups at PMOD/WRC in Davos, Switzerland. A small correction of each group may be required in the future, and this study examines the methods and implications of this on data sets collected at four remote baseline stations since the 1990s. The goal is to develop a better estimate of the solar and terrestrial radiation budget at the Earth's surface.
Guanyu Huang, Xiong Liu, Kelly Chance, Kai Yang, Pawan K. Bhartia, Zhaonan Cai, Marc Allaart, Gérard Ancellet, Bertrand Calpini, Gerrie J. R. Coetzee, Emilio Cuevas-Agulló, Manuel Cupeiro, Hugo De Backer, Manvendra K. Dubey, Henry E. Fuelberg, Masatomo Fujiwara, Sophie Godin-Beekmann, Tristan J. Hall, Bryan Johnson, Everette Joseph, Rigel Kivi, Bogumil Kois, Ninong Komala, Gert König-Langlo, Giovanni Laneve, Thierry Leblanc, Marion Marchand, Kenneth R. Minschwaner, Gary Morris, Michael J. Newchurch, Shin-Ya Ogino, Nozomu Ohkawara, Ankie J. M. Piters, Françoise Posny, Richard Querel, Rinus Scheele, Frank J. Schmidlin, Russell C. Schnell, Otto Schrems, Henry Selkirk, Masato Shiotani, Pavla Skrivánková, René Stübi, Ghassan Taha, David W. Tarasick, Anne M. Thompson, Valérie Thouret, Matthew B. Tully, Roeland Van Malderen, Holger Vömel, Peter von der Gathen, Jacquelyn C. Witte, and Margarita Yela
Atmos. Meas. Tech., 10, 2455–2475, https://doi.org/10.5194/amt-10-2455-2017, https://doi.org/10.5194/amt-10-2455-2017, 2017
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It is essential to understand the data quality of +10-year OMI ozone product and impacts of the “row anomaly” (RA). We validate the OMI Ozone Profile (PROFOZ) product from Oct 2004 to Dec 2014 against ozonesonde observations globally. Generally, OMI has good agreement with ozonesondes. The spatiotemporal variation of retrieval performance suggests the need to improve OMI’s radiometric calibration especially during the post-RA period to maintain the long-term stability.
Thomas Carlund, Natalia Kouremeti, Stelios Kazadzis, and Julian Gröbner
Atmos. Meas. Tech., 10, 905–923, https://doi.org/10.5194/amt-10-905-2017, https://doi.org/10.5194/amt-10-905-2017, 2017
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Aerosols play an important role in atmospheric processes. Aerosol optical depth is the most common measure of columnar aerosol load. We present a sunphotometer called UVPFR that is able to measure aerosol optical depth in the ultraviolet range, including the calibration, characterization and validation of the instrument/measurements. The instrument will serve as a reference on the intercalibration of Brewer spectrophotometers that are also able to measure aerosol optical depth in the UV region.
Christos S. Zerefos, Kostas Eleftheratos, John Kapsomenakis, Stavros Solomos, Antje Inness, Dimitris Balis, Alberto Redondas, Henk Eskes, Marc Allaart, Vassilis Amiridis, Arne Dahlback, Veerle De Bock, Henri Diémoz, Ronny Engelmann, Paul Eriksen, Vitali Fioletov, Julian Gröbner, Anu Heikkilä, Irina Petropavlovskikh, Janusz Jarosławski, Weine Josefsson, Tomi Karppinen, Ulf Köhler, Charoula Meleti, Christos Repapis, John Rimmer, Vladimir Savinykh, Vadim Shirotov, Anna Maria Siani, Andrew R. D. Smedley, Martin Stanek, and René Stübi
Atmos. Chem. Phys., 17, 551–574, https://doi.org/10.5194/acp-17-551-2017, https://doi.org/10.5194/acp-17-551-2017, 2017
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The paper makes a convincing case that the Brewer network is capable of detecting enhanced SO2 columns, as observed, e.g., after volcanic eruptions. For this reason, large volcanic eruptions of the past decade have been used to detect and forecast SO2 plumes of volcanic origin using the Brewer and other ground-based networks, aided by satellite, trajectory analysis calculations and modelling.
Luca Egli, Julian Gröbner, Gregor Hülsen, Luciano Bachmann, Mario Blumthaler, Jimmy Dubard, Marina Khazova, Richard Kift, Kees Hoogendijk, Antonio Serrano, Andrew Smedley, and José-Manuel Vilaplana
Atmos. Meas. Tech., 9, 1553–1567, https://doi.org/10.5194/amt-9-1553-2016, https://doi.org/10.5194/amt-9-1553-2016, 2016
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Array spectroradiometers are small, light, robust and cost-effective instruments, and are increasingly used for atmospheric measurements. The quality of array spectroradiometers is assessed for the reliable quantification of ultraviolet radiation (UV) in order to monitor the exposure of UV radiation to human health. The study shows that reliable UV measurements with these instruments are limited for observations around noon and show large biases in the morning and evening.
África Barreto, Emilio Cuevas, María-José Granados-Muñoz, Lucas Alados-Arboledas, Pedro M. Romero, Julian Gröbner, Natalia Kouremeti, Antonio F. Almansa, Tom Stone, Carlos Toledano, Roberto Román, Mikhail Sorokin, Brent Holben, Marius Canini, and Margarita Yela
Atmos. Meas. Tech., 9, 631–654, https://doi.org/10.5194/amt-9-631-2016, https://doi.org/10.5194/amt-9-631-2016, 2016
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This paper presents the new photometer CE318-T, able to perform daytime and
night-time photometric measurements using the sun and the moon as light
sources. This new device permits a complete cycle of diurnal aerosol and water vapour measurements to be extracted, valuable to enhance atmospheric monitoring. We have also highlighted the ability of this new device to capture short-term atmospheric variations, critical for climate studies.
Y. Bühler, M. Marty, L. Egli, J. Veitinger, T. Jonas, P. Thee, and C. Ginzler
The Cryosphere, 9, 229–243, https://doi.org/10.5194/tc-9-229-2015, https://doi.org/10.5194/tc-9-229-2015, 2015
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We are able to map snow depth over large areas ( > 100km2) using airborne digital photogrammetry. Digital photogrammetry is more economical than airborne Laser Scanning but slightly less accurate. Comparisons to independent snow depth measurements reveal an accuracy of about 30cm. Spatial continuous mapping of snow depth is a major step forward compared to point measurements usually applied today. Limitations are steep slopes (> 50°) and areas covered by trees and scrubs.
M. Lothon, F. Lohou, D. Pino, F. Couvreux, E. R. Pardyjak, J. Reuder, J. Vilà-Guerau de Arellano, P Durand, O. Hartogensis, D. Legain, P. Augustin, B. Gioli, D. H. Lenschow, I. Faloona, C. Yagüe, D. C. Alexander, W. M. Angevine, E Bargain, J. Barrié, E. Bazile, Y. Bezombes, E. Blay-Carreras, A. van de Boer, J. L. Boichard, A. Bourdon, A. Butet, B. Campistron, O. de Coster, J. Cuxart, A. Dabas, C. Darbieu, K. Deboudt, H. Delbarre, S. Derrien, P. Flament, M. Fourmentin, A. Garai, F. Gibert, A. Graf, J. Groebner, F. Guichard, M. A. Jiménez, M. Jonassen, A. van den Kroonenberg, V. Magliulo, S. Martin, D. Martinez, L. Mastrorillo, A. F. Moene, F. Molinos, E. Moulin, H. P. Pietersen, B. Piguet, E. Pique, C. Román-Cascón, C. Rufin-Soler, F. Saïd, M. Sastre-Marugán, Y. Seity, G. J. Steeneveld, P. Toscano, O. Traullé, D. Tzanos, S. Wacker, N. Wildmann, and A. Zaldei
Atmos. Chem. Phys., 14, 10931–10960, https://doi.org/10.5194/acp-14-10931-2014, https://doi.org/10.5194/acp-14-10931-2014, 2014
S. Kazadzis, I. Veselovskii, V. Amiridis, J. Gröbner, A. Suvorina, S. Nyeki, E. Gerasopoulos, N. Kouremeti, M. Taylor, A. Tsekeri, and C. Wehrli
Atmos. Meas. Tech., 7, 2013–2025, https://doi.org/10.5194/amt-7-2013-2014, https://doi.org/10.5194/amt-7-2013-2014, 2014
A. Stenke, C. R. Hoyle, B. Luo, E. Rozanov, J. Gröbner, L. Maag, S. Brönnimann, and T. Peter
Atmos. Chem. Phys., 13, 9713–9729, https://doi.org/10.5194/acp-13-9713-2013, https://doi.org/10.5194/acp-13-9713-2013, 2013
T. Egorova, E. Rozanov, J. Gröbner, M. Hauser, and W. Schmutz
Atmos. Chem. Phys., 13, 3811–3823, https://doi.org/10.5194/acp-13-3811-2013, https://doi.org/10.5194/acp-13-3811-2013, 2013
Related subject area
Subject: Others (Wind, Precipitation, Temperature, etc.) | Technique: Remote Sensing | Topic: Data Processing and Information Retrieval
Observations of tall-building wakes using a scanning Doppler lidar
Mid-Atlantic nocturnal low-level jet characteristics: a machine learning analysis of radar wind profiles
Mitigating radome-induced bias in X-band weather radar polarimetric moments using an adaptive discrete Fourier transform algorithm
GNSS-RO residual ionospheric error (RIE): a new method and assessment
Benchmarking KDP in rainfall: a quantitative assessment of estimation algorithms using C-band weather radar observations
Comparative experimental validation of microwave hyperspectral atmospheric soundings in clear-sky conditions
Global Navigation Satellite System (GNSS) radio occultation climatologies mapped by machine learning and Bayesian interpolation
Determination of low-level temperature profiles from microwave radiometer observations during rain
Aeolus lidar surface return (LSR) at 355 nm as a new Aeolus Level-2A product
Sampling the diurnal and annual cycles of the Earth's energy imbalance with constellations of satellite-borne radiometers
Retrieval of top-of-atmosphere fluxes from combined EarthCARE lidar, imager, and broadband radiometer observations: the BMA-FLX product
Analysis of the measurement uncertainty for a 3D wind lidar
Improving solution availability and temporal consistency of an optimal-estimation physical retrieval for ground-based thermodynamic boundary layer profiling
An improved geolocation methodology for spaceborne radar and lidar systems
Combining low- and high-frequency microwave radiometer measurements from the MOSAiC expedition for enhanced water vapour products
Characterizing Urban Planetary Boundary Layer Dynamics Using 3-Year Doppler Wind Lidar Measurements in a Western Yangtze River Delta City, China
HAMSTER: Hyperspectral Albedo Maps dataset with high Spatial and TEmporal Resolution
Improved consistency in solar-induced fluorescence retrievals from GOME-2A with the SIFTER v3 algorithm
Global-scale gravity wave analysis methodology for the ESA Earth Explorer 11 candidate CAIRT
Retrieval of pseudo-BRDF-adjusted surface reflectance at 440 nm from the Geostationary Environmental Monitoring Spectrometer (GEMS)
Combining commercial microwave links and weather radar for classification of dry snow and rainfall
Drop size distribution retrieval using dual-polarization radar at C-band and S-band
An information content approach to diagnosing and improving CLIMCAPS retrievals across instruments and satellites
Thermal tides in the middle atmosphere at mid-latitudes measured with a ground-based microwave radiometer
Global sensitivity analysis of simulated remote sensing polarimetric observations over snow
Improving the Gaussianity of radar reflectivity departures between observations and simulations using symmetric rain rates
On the temperature stability requirements of free-running Nd:YAG lasers for atmospheric temperature profiling through the rotational Raman technique
Limitations in wavelet analysis of non-stationary atmospheric gravity wave signatures in temperature profiles
A new non-linearity correction method for the spectrum from the Geostationary Inferometric Infrared Sounder on board Fengyun-4 satellites and its preliminary assessments
Determination of high-precision tropospheric delays using crowdsourced smartphone GNSS data
Unfiltering of the EarthCARE Broadband Radiometer (BBR) observations: the BM-RAD product
Variance estimations in the presence of intermittent interference and their applications to incoherent scatter radar signal processing
A clustering-based method for identifying and tracking squall lines
A multi-instrument fuzzy logic boundary-layer-top detection algorithm
Sensitivity of thermodynamic profiles retrieved from ground-based microwave and infrared observations to additional input data from active remote sensing instruments and numerical weather prediction models
Scale separation for gravity wave analysis from 3D temperature observations in the mesosphere and lower thermosphere (MLT) region
Estimating the refractivity bias of FORMOSAT-7/COSMIC-2 Global Navigation Satellite System (GNSS) radio occultation in the deep troposphere
High Spectral Resolution Lidar – generation 2 (HSRL-2) retrievals of ocean surface wind speed: methodology and evaluation
Dual adaptive differential threshold method for automated detection of faint and strong echo features in radar observations of winter storms
Noise filtering options for conically scanning Doppler lidar measurements with low pulse accumulation
Measuring rainfall using microwave links: the influence of temporal sampling
Drone-based photogrammetry combined with deep learning to estimate hail size distributions and melting of hail on the ground
The High lAtitude sNowfall Detection and Estimation aLgorithm for ATMS (HANDEL-ATMS): a new algorithm for snowfall retrieval at high latitudes
Next-generation radiance unfiltering process for the Clouds and the Earth's Radiant Energy System instrument
Improved rain event detection in commercial microwave link time series via combination with MSG SEVIRI data
A directional surface reflectance climatology determined from TROPOMI observations
Investigation of gravity waves using measurements from a sodium temperature/wind lidar operated in multi-direction mode
An improved BRDF hotspot model and its use in VLIDORT for studying the impact of atmospheric scattering on hotspot directional signatures in the atmosphere
A multi-decadal time series of upper stratospheric temperature profiles from Odin-OSIRIS limb-scattered spectra
Radar based high resolution ensemble precipitation analyses over the French Alps
Natalie E. Theeuwes, Janet F. Barlow, Antti Mannisenaho, Denise Hertwig, Ewan O'Connor, and Alan Robins
Atmos. Meas. Tech., 18, 1355–1371, https://doi.org/10.5194/amt-18-1355-2025, https://doi.org/10.5194/amt-18-1355-2025, 2025
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A Doppler lidar was placed in a highly built-up area in London to measure wakes from tall buildings during a period of 1 year. We were able to detect wakes and assess their dependence on wind speed, wind direction, and atmospheric stability.
Maurice Roots, John T. Sullivan, and Belay Demoz
Atmos. Meas. Tech., 18, 1269–1282, https://doi.org/10.5194/amt-18-1269-2025, https://doi.org/10.5194/amt-18-1269-2025, 2025
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This paper presents a supervised-machine-learning approach for the automatic isolation of nocturnal low-level jets (NLLJs) using observations from a radar wind profiler. This analysis isolated 90 southwesterly NLLJs observed from May to September 2017–2021, highlighting key features in the evolution and morphology of the mid-Atlantic NLLJ.
Padmanabhan Thiruvengadam, Guillaume Lesage, Ambinintsoa Volatiana Ramanamahefa, and Joël Van Baelen
Atmos. Meas. Tech., 18, 1185–1191, https://doi.org/10.5194/amt-18-1185-2025, https://doi.org/10.5194/amt-18-1185-2025, 2025
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This study explores how the joints in a weather radar's protective cover affect its measurements. We developed a new method to correct these errors, improving the accuracy of the radar's data. Our method was tested during an intense cyclone on Réunion Island, demonstrating significant improvements in data accuracy. This research is crucial for enhancing weather predictions and understanding, particularly in challenging terrains.
Dong L. Wu, Valery A. Yudin, Kyu-Myong Kim, Mohar Chattopadhyay, Lawrence Coy, Ruth S. Lieberman, C. C. Jude H. Salinas, Jae N. Lee, Jie Gong, and Guiping Liu
Atmos. Meas. Tech., 18, 843–863, https://doi.org/10.5194/amt-18-843-2025, https://doi.org/10.5194/amt-18-843-2025, 2025
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Global Navigation Satellite System radio occultation data help monitor climate and weather prediction but are affected by residual ionospheric errors (RIEs). A new excess-phase-gradient method detects and corrects RIEs, showing both positive and negative values, varying by latitude, time, and solar activity. Tests show that RIE impacts polar stratosphere temperatures in models, with differences up to 3–4 K. This highlights the need for RIE correction to improve the accuracy of data assimilation.
Miguel Aldana, Seppo Pulkkinen, Annakaisa von Lerber, Matthew R. Kumjian, and Dmitri Moisseev
Atmos. Meas. Tech., 18, 793–816, https://doi.org/10.5194/amt-18-793-2025, https://doi.org/10.5194/amt-18-793-2025, 2025
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Accurate KDP estimates are crucial in radar-based applications. We quantify the uncertainties of several publicly available KDP estimation methods for multiple rainfall intensities. We use C-band weather radar observations and employed a self-consistency KDP, estimated from reflectivity and differential reflectivity, as a framework for the examination. Our study provides guidance for the performance, uncertainties, and optimisation of the methods, focusing mainly on accuracy and robustness.
Lei Liu, Natalia Bliankinshtein, Yi Huang, John R. Gyakum, Philip M. Gabriel, Shiqi Xu, and Mengistu Wolde
Atmos. Meas. Tech., 18, 471–485, https://doi.org/10.5194/amt-18-471-2025, https://doi.org/10.5194/amt-18-471-2025, 2025
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This study evaluates and compares a new microwave hyperspectrometer with an infrared hyperspectrometer for clear-sky temperature and water vapor retrievals. The analysis reveals that the information content of the infrared hyperspectrometer exceeds that of the microwave hyperspectrometer and provides higher vertical resolution in ground-based zenith measurements. Leveraging the ground–airborne synergy between the two instruments yielded optimal sounding results.
Endrit Shehaj, Stephen Leroy, Kerri Cahoy, Alain Geiger, Laura Crocetti, Gregor Moeller, Benedikt Soja, and Markus Rothacher
Atmos. Meas. Tech., 18, 57–72, https://doi.org/10.5194/amt-18-57-2025, https://doi.org/10.5194/amt-18-57-2025, 2025
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This work investigates whether machine learning (ML) can offer an alternative to existing methods to map radio occultation (RO) products, allowing the extraction of information not visible in direct observations. ML can further improve the results of Bayesian interpolation, a state-of-the-art method to map RO observations. The results display improvements in horizontal and temporal domains, at heights ranging from the planetary boundary layer up to the lower stratosphere, and for all seasons.
Andreas Foth, Moritz Lochmann, Pablo Saavedra Garfias, and Heike Kalesse-Los
Atmos. Meas. Tech., 17, 7169–7181, https://doi.org/10.5194/amt-17-7169-2024, https://doi.org/10.5194/amt-17-7169-2024, 2024
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Microwave radiometers are usually not able to provide atmospheric quantities such as temperature profiles during rain. We present a method based on a selection of specific frequencies and elevation angles from microwave radiometer observations. A comparison with a numerical weather prediction model shows the presented method allows low-level temperature profiles during rain to be resolved, with rain rates of up to 2.5 mm h−1,, which was not possible before with state-of-the-art retrievals.
Lev D. Labzovskii, Gerd-Jan van Zadelhoff, David P. Donovan, Jos de Kloe, L. Gijsbert Tilstra, Ad Stoffelen, Damien Josset, and Piet Stammes
Atmos. Meas. Tech., 17, 7183–7208, https://doi.org/10.5194/amt-17-7183-2024, https://doi.org/10.5194/amt-17-7183-2024, 2024
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The Atmospheric Laser Doppler Instrument (ALADIN) on the Aeolus satellite was the first of its kind to measure high-resolution vertical profiles of aerosols and cloud properties from space. We present an algorithm that produces Aeolus lidar surface returns (LSRs), containing useful information for measuring UV reflectivity. Aeolus LSRs matched well with existing UV reflectivity data from other satellites, like GOME-2 and TROPOMI, and demonstrated excellent sensitivity to modeled snow cover.
Thomas Hocking, Thorsten Mauritsen, and Linda Megner
Atmos. Meas. Tech., 17, 7077–7095, https://doi.org/10.5194/amt-17-7077-2024, https://doi.org/10.5194/amt-17-7077-2024, 2024
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The imbalance between the energy the Earth absorbs from the Sun and the energy the Earth emits back into space gives rise to climate change, but measuring the small imbalance is challenging. We simulate satellites in various orbits to investigate how well they sample the imbalance and find that the best option is to combine at least two satellites that see complementary parts of the Earth and cover the daily and annual cycles. This information is useful when planning future satellite missions.
Almudena Velázquez Blázquez, Carlos Domenech, Edward Baudrez, Nicolas Clerbaux, Carla Salas Molar, and Nils Madenach
Atmos. Meas. Tech., 17, 7007–7026, https://doi.org/10.5194/amt-17-7007-2024, https://doi.org/10.5194/amt-17-7007-2024, 2024
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This paper focuses on the BMA-FLX processor, in which thermal and solar top-of-atmosphere radiative fluxes are obtained from longwave and shortwave radiances measured along track by the EarthCARE Broadband Radiometer (BBR). The BBR measurements, at three fixed viewing angles (fore, nadir, aft), are co-registered either at the surface or at a reference level. A combined flux from the three BRR views is obtained. The algorithm has been successfully validated against test scenes.
Wolf Knöller, Gholamhossein Bagheri, Philipp von Olshausen, and Michael Wilczek
Atmos. Meas. Tech., 17, 6913–6931, https://doi.org/10.5194/amt-17-6913-2024, https://doi.org/10.5194/amt-17-6913-2024, 2024
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Three-dimensional (3D) wind velocity measurements are of major importance for the characterization of atmospheric turbulence. This paper presents a detailed study of the measurement uncertainty of a three-beam wind lidar designed for mounting on airborne platforms. Considering the geometrical constraints, the analysis provides quantitative estimates for the measurement uncertainty of all components of the 3D wind vector. As a result, we propose optimized post-processing for error reduction.
Bianca Adler, David D. Turner, Laura Bianco, Irina V. Djalalova, Timothy Myers, and James M. Wilczak
Atmos. Meas. Tech., 17, 6603–6624, https://doi.org/10.5194/amt-17-6603-2024, https://doi.org/10.5194/amt-17-6603-2024, 2024
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Continuous profile observations of temperature and humidity in the lowest part of the atmosphere are essential for the evaluation of numerical weather prediction models and data assimilation for better weather forecasts. Such profiles can be retrieved from passive ground-based remote sensing instruments like infrared spectrometers and microwave radiometers. In this study, we describe three recent modifications to the retrieval framework TROPoe for improved temperature and humidity profiles.
Bernat Puigdomènech Treserras and Pavlos Kollias
Atmos. Meas. Tech., 17, 6301–6314, https://doi.org/10.5194/amt-17-6301-2024, https://doi.org/10.5194/amt-17-6301-2024, 2024
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The paper presents a comprehensive approach to improve the geolocation accuracy of spaceborne radar and lidar systems, crucial for the successful interpretation of data from the upcoming EarthCARE mission. The paper details the technical background of the presented methods and various examples of geolocation analyses, including a short period of CloudSat observations when the star tracker was not operating properly and lifetime statistics from the CloudSat and CALIPSO missions.
Andreas Walbröl, Hannes J. Griesche, Mario Mech, Susanne Crewell, and Kerstin Ebell
Atmos. Meas. Tech., 17, 6223–6245, https://doi.org/10.5194/amt-17-6223-2024, https://doi.org/10.5194/amt-17-6223-2024, 2024
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We developed retrievals of integrated water vapour (IWV), temperature profiles, and humidity profiles from ground-based passive microwave remote sensing measurements gathered during the MOSAiC expedition. We demonstrate and quantify the benefit of combining low- and high-frequency microwave radiometers to improve humidity profiling and IWV estimates by comparing the retrieved quantities to single-instrument retrievals and reference datasets (radiosondes).
Tianwen Wei, Mengya Wang, Kenan Wu, Jinlong Yuan, Haiyun Xia, and Simone Lolli
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-178, https://doi.org/10.5194/amt-2024-178, 2024
Revised manuscript accepted for AMT
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This study uses three years of wind lidar measurements to investigate the dynamics of the urban PBL in Hefei, China. Results show that nocturnal low-level jets occur most frequently in spring and intensify in summer, significantly increasing turbulence and shear intensity near the ground level, especially during the night. Cloud cover raises the MLH by around 100 m during the night due to the greenhouse effect and decreases it by up to 200 m in the afternoon by obstructing solar radiation.
Giulia Roccetti, Luca Bugliaro, Felix Gödde, Claudia Emde, Ulrich Hamann, Mihail Manev, Michael Fritz Sterzik, and Cedric Wehrum
Atmos. Meas. Tech., 17, 6025–6046, https://doi.org/10.5194/amt-17-6025-2024, https://doi.org/10.5194/amt-17-6025-2024, 2024
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The amount of sunlight reflected by the Earth’s surface (albedo) is vital for the Earth's radiative system. While satellite instruments offer detailed spatial and temporal albedo maps, they only cover seven wavelength bands. We generate albedo maps that fully span the visible and near-infrared range using a machine learning algorithm. These maps reveal how the reflectivity of different land surfaces varies throughout the year. Our dataset enhances the understanding of the Earth's energy balance.
Juliëtte C. S. Anema, K. Folkert Boersma, Lieuwe G. Tilstra, Olaf N. E. Tuinder, and Willem W. Verstraeten
EGUsphere, https://doi.org/10.5194/egusphere-2024-2666, https://doi.org/10.5194/egusphere-2024-2666, 2024
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Long-term records of plant fluorescence offer vital insights into changing vegetation activity. The GOME-2A sensor provides extensive global observations but suffers from calibration and instrument degradation that affect data consistency. This study presents the SIFTER v3 algorithm, which effectively resolves these issues and includes other improvements, resulting in robust, accurate, and consistent GOME-2A fluorescence measurements from 2007 to 2017.
Sebastian Rhode, Peter Preusse, Jörn Ungermann, Inna Polichtchouk, Kaoru Sato, Shingo Watanabe, Manfred Ern, Karlheinz Nogai, Björn-Martin Sinnhuber, and Martin Riese
Atmos. Meas. Tech., 17, 5785–5819, https://doi.org/10.5194/amt-17-5785-2024, https://doi.org/10.5194/amt-17-5785-2024, 2024
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We investigate the capabilities of a proposed satellite mission, CAIRT, for observing gravity waves throughout the middle atmosphere and present the necessary methodology for in-depth wave analysis. Our findings suggest that such a satellite mission is highly capable of resolving individual wave parameters and could give new insights into the role of gravity waves in general atmospheric circulation and atmospheric processes.
Suyoung Sim, Sungwon Choi, Daeseong Jung, Jongho Woo, Nayeon Kim, Sungwoo Park, Honghee Kim, Ukkyo Jeong, Hyunkee Hong, and Kyung-Soo Han
Atmos. Meas. Tech., 17, 5601–5618, https://doi.org/10.5194/amt-17-5601-2024, https://doi.org/10.5194/amt-17-5601-2024, 2024
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This study evaluates the use of background surface reflectance (BSR) derived from a semi-empirical bidirectional reflectance distribution function (BRDF) model based on GEMS satellite images. Analysis shows that BSR provides improved accuracy and stability compared to Lambertian-equivalent reflectivity (LER). These results indicate that BSR can significantly enhance climate analysis and air quality monitoring, making it a promising tool for accurate environmental satellite applications.
Erlend Øydvin, Renaud Gaban, Jafet Andersson, Remco van de Beek, Mareile Astrid Wolff, Nils-Otto Kitterød, Christian Chwala, and Vegard Nilsen
EGUsphere, https://doi.org/10.5194/egusphere-2024-2625, https://doi.org/10.5194/egusphere-2024-2625, 2024
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We present a novel method for classifying rain and snow by combining data from Commercial Microwave Links (CMLs) with weather radar. We compare this to a reference method using dew point temperature for precipitation type classification. Evaluations with nearby disdrometers show that CMLs improve the classification of dry snow and rainfall, outperforming the reference method.
Daniel Durbin, Yadong Wang, and Pao-Liang Chang
Atmos. Meas. Tech., 17, 5397–5411, https://doi.org/10.5194/amt-17-5397-2024, https://doi.org/10.5194/amt-17-5397-2024, 2024
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A method for determining drop size distributions (DSDs) for rain using radar measurements from two frequencies at two polarizations is presented. Following some preprocessing and quality control, radar measurements are incorporated into a model that uses swarm intelligence to seek the most suitable DSD to produce the input measurements.
Nadia Smith and Christopher D. Barnet
EGUsphere, https://doi.org/10.5194/egusphere-2024-2448, https://doi.org/10.5194/egusphere-2024-2448, 2024
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CLIMCAPS extends the Aqua AIRS+AMSU record with retrievals from CrIS+ATMS on Suomi National Polar-orbiting Partnership (SNPP) and Joint Polar Satellite System series (JPSS-1 to JPSS-4). With “continuous” we mean a data record that is consistent in its characterization of natural variation despite changes in source instrumentation. Here we investigate how sounding continuity can improved across the full CLIMCAPS record (2002 to present day) spanning multiple instruments and satellites.
Witali Krochin, Axel Murk, and Gunter Stober
Atmos. Meas. Tech., 17, 5015–5028, https://doi.org/10.5194/amt-17-5015-2024, https://doi.org/10.5194/amt-17-5015-2024, 2024
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Atmospheric tides are global-scale oscillations with periods of a fraction of a day. Their observation in the middle atmosphere is challenging and rare, as it requires continuous measurements with a high temporal resolution. In this paper, temperature time series of a ground-based microwave radiometer were analyzed with a spectral filter to derive thermal tide amplitudes and phases in an altitude range of 25–50 km at the geographical locations of Payerne and Bern (Switzerland).
Matteo Ottaviani, Gabriel Harris Myers, and Nan Chen
Atmos. Meas. Tech., 17, 4737–4756, https://doi.org/10.5194/amt-17-4737-2024, https://doi.org/10.5194/amt-17-4737-2024, 2024
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We analyze simulated polarization observations over snow to investigate the capabilities of remote sensing to determine surface and atmospheric properties in snow-covered regions. Polarization measurements are demonstrated to aid in the determination of snow grain shape, ice crystal roughness, and the vertical distribution of impurities in the snow–atmosphere system, data that are critical for estimating snow albedo for use in climate models.
Yudong Gao, Lidou Huyan, Zheng Wu, and Bojun Liu
Atmos. Meas. Tech., 17, 4675–4686, https://doi.org/10.5194/amt-17-4675-2024, https://doi.org/10.5194/amt-17-4675-2024, 2024
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A symmetric error model built by symmetric rain rates handles the non-Gaussian error structure of the reflectivity error. The accuracy and linearization of rain rates can further improve the Gaussianity.
José Alex Zenteno-Hernández, Adolfo Comerón, Federico Dios, Alejandro Rodríguez-Gómez, Constantino Muñoz-Porcar, Michaël Sicard, Noemi Franco, Andreas Behrendt, and Paolo Di Girolamo
Atmos. Meas. Tech., 17, 4687–4694, https://doi.org/10.5194/amt-17-4687-2024, https://doi.org/10.5194/amt-17-4687-2024, 2024
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We study how the spectral characteristics of a solid-state laser in an atmospheric temperature profiling lidar using the Raman technique impact the temperature retrieval accuracy. We find that the spectral widening, with respect to a seeded laser, has virtually no impact, while crystal-rod temperature variations in the laser must be kept within a range of 1 K for the uncertainty in the atmospheric temperature below 1 K. The study is carried out through spectroscopy simulations.
Robert Reichert, Natalie Kaifler, and Bernd Kaifler
Atmos. Meas. Tech., 17, 4659–4673, https://doi.org/10.5194/amt-17-4659-2024, https://doi.org/10.5194/amt-17-4659-2024, 2024
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Imagine you want to determine how quickly the pitch of a passing ambulance’s siren changes. If the vehicle is traveling slowly, the pitch changes only slightly, but if it is traveling fast, the pitch also changes rapidly. In a similar way, the wind in the middle atmosphere modulates the wavelength of atmospheric gravity waves. We have investigated the question of how strong the maximum wind may be so that the change in wavelength can still be determined with the help of wavelet transformation.
Qiang Guo, Yuning Liu, Xin Wang, and Wen Hui
Atmos. Meas. Tech., 17, 4613–4627, https://doi.org/10.5194/amt-17-4613-2024, https://doi.org/10.5194/amt-17-4613-2024, 2024
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Non-linearity (NL) correction is a critical procedure to guarantee that the calibration accuracy of a spaceborne sensor approaches a reasonable level. Different from the classical method, a new NL correction method for a spaceborne Fourier transform spectrometer is proposed. To overcome the inaccurate linear coefficient from two-point calibration influencing NL correction, an iteration algorithm is established that is suitable for NL correction of both infrared and microwave sensors.
Yuanxin Pan, Grzegorz Kłopotek, Laura Crocetti, Rudi Weinacker, Tobias Sturn, Linda See, Galina Dick, Gregor Möller, Markus Rothacher, Ian McCallum, Vicente Navarro, and Benedikt Soja
Atmos. Meas. Tech., 17, 4303–4316, https://doi.org/10.5194/amt-17-4303-2024, https://doi.org/10.5194/amt-17-4303-2024, 2024
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Crowdsourced smartphone GNSS data were processed with a dedicated data processing pipeline and could produce millimeter-level accurate estimates of zenith total delay (ZTD) – a critical atmospheric variable. This breakthrough not only demonstrates the feasibility of using ubiquitous devices for high-precision atmospheric monitoring but also underscores the potential for a global, cost-effective tropospheric monitoring network.
Almudena Velázquez Blázquez, Edward Baudrez, Nicolas Clerbaux, and Carlos Domenech
Atmos. Meas. Tech., 17, 4245–4256, https://doi.org/10.5194/amt-17-4245-2024, https://doi.org/10.5194/amt-17-4245-2024, 2024
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The Broadband Radiometer measures shortwave and total-wave radiances filtered by the spectral response of the instrument. To obtain unfiltered solar and thermal radiances, the effect of the spectral response needs to be corrected for, done within the BM-RAD processor. Errors in the unfiltering are propagated into fluxes; thus, accurate unfiltering is required for their proper estimation (within BMA-FLX). Unfiltering errors are estimated to be <0.5 % for the shortwave and <0.1 % for the longwave.
Qihou Zhou, Yanlin Li, and Yun Gong
Atmos. Meas. Tech., 17, 4197–4209, https://doi.org/10.5194/amt-17-4197-2024, https://doi.org/10.5194/amt-17-4197-2024, 2024
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We discuss several robust estimators to compute the variance of a normally distributed random variable to deal with interference. Compared to rank-based estimators, the methods based on the geometric mean are more accurate and are computationally more efficient. We apply three robust estimators to incoherent scatter power and velocity processing, along with the traditional sample mean estimator. The best estimator is a hybrid estimator that combines the sample mean and a robust estimator.
Zhao Shi, Yuxiang Wen, and Jianxin He
Atmos. Meas. Tech., 17, 4121–4135, https://doi.org/10.5194/amt-17-4121-2024, https://doi.org/10.5194/amt-17-4121-2024, 2024
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The squall line is a type of convective system. Squall lines are often associated with damaging weather, so identifying and tracking squall lines plays an important role in early meteorological disaster warnings. A clustering-based method is proposed in this article. It can identify the squall lines within the radar scanning range with an accuracy rate of 95.93 %. It can also provide the three-dimensional structure and movement tracking results for each squall line.
Elizabeth N. Smith and Jacob T. Carlin
Atmos. Meas. Tech., 17, 4087–4107, https://doi.org/10.5194/amt-17-4087-2024, https://doi.org/10.5194/amt-17-4087-2024, 2024
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Boundary-layer height observations remain sparse in time and space. In this study we create a new fuzzy logic method for synergistically combining boundary-layer height estimates from a suite of instruments. These estimates generally compare well to those from radiosondes; plus, the approach offers near-continuous estimates through the entire diurnal cycle. Suspected reasons for discrepancies are discussed. The code for the newly presented fuzzy logic method is provided for the community to use.
Laura Bianco, Bianca Adler, Ludovic Bariteau, Irina V. Djalalova, Timothy Myers, Sergio Pezoa, David D. Turner, and James M. Wilczak
Atmos. Meas. Tech., 17, 3933–3948, https://doi.org/10.5194/amt-17-3933-2024, https://doi.org/10.5194/amt-17-3933-2024, 2024
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The Tropospheric Remotely Observed Profiling via Optimal Estimation physical retrieval is used to retrieve temperature and humidity profiles from various combinations of passive and active remote sensing instruments, surface platforms, and numerical weather prediction models. The retrieved profiles are assessed against collocated radiosonde in non-cloudy conditions to assess the sensitivity of the retrievals to different input combinations. Case studies with cloudy conditions are also inspected.
Björn Linder, Peter Preusse, Qiuyu Chen, Ole Martin Christensen, Lukas Krasauskas, Linda Megner, Manfred Ern, and Jörg Gumbel
Atmos. Meas. Tech., 17, 3829–3841, https://doi.org/10.5194/amt-17-3829-2024, https://doi.org/10.5194/amt-17-3829-2024, 2024
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The Swedish research satellite MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is designed to study atmospheric waves in the mesosphere and lower thermosphere. These waves perturb the temperature field, and thus, by observing three-dimensional temperature fluctuations, their properties can be quantified. This pre-study uses synthetic MATS data generated from a general circulation model to investigate how well wave properties can be retrieved.
Gia Huan Pham, Shu-Chih Yang, Chih-Chien Chang, Shu-Ya Chen, and Cheng Yung Huang
Atmos. Meas. Tech., 17, 3605–3623, https://doi.org/10.5194/amt-17-3605-2024, https://doi.org/10.5194/amt-17-3605-2024, 2024
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This research examines the characteristics of low-level GNSS radio occultation (RO) refractivity bias over ocean and land and its dependency on the RO retrieval uncertainty, atmospheric temperature, and moisture. We propose methods for estimating the region-dependent refractivity bias. Our methods can be applied to calibrate the refractivity bias under different atmospheric conditions and thus improve the applications of the GNSS RO data in the deep troposphere.
Sanja Dmitrovic, Johnathan W. Hair, Brian L. Collister, Ewan Crosbie, Marta A. Fenn, Richard A. Ferrare, David B. Harper, Chris A. Hostetler, Yongxiang Hu, John A. Reagan, Claire E. Robinson, Shane T. Seaman, Taylor J. Shingler, Kenneth L. Thornhill, Holger Vömel, Xubin Zeng, and Armin Sorooshian
Atmos. Meas. Tech., 17, 3515–3532, https://doi.org/10.5194/amt-17-3515-2024, https://doi.org/10.5194/amt-17-3515-2024, 2024
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This study introduces and evaluates a new ocean surface wind speed product from the NASA Langley Research Center (LARC) airborne High-Spectral-Resolution Lidar – Generation 2 (HSRL-2) during the NASA ACTIVATE mission. We show that HSRL-2 surface wind speed data are accurate when compared to ground-truth dropsonde measurements. Therefore, the HSRL-2 instrument is able obtain accurate, high-resolution surface wind speed data in airborne field campaigns.
Laura M. Tomkins, Sandra E. Yuter, and Matthew A. Miller
Atmos. Meas. Tech., 17, 3377–3399, https://doi.org/10.5194/amt-17-3377-2024, https://doi.org/10.5194/amt-17-3377-2024, 2024
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We have created a new method to better identify enhanced features in radar data from winter storms. Unlike the clear-cut features seen in warm-season storms, features in winter storms are often fuzzier with softer edges. Our technique is unique because it uses two adaptive thresholds that change based on the background radar values. It can identify both strong and subtle features in the radar data and takes into account uncertainties in the detection process.
Eileen Päschke and Carola Detring
Atmos. Meas. Tech., 17, 3187–3217, https://doi.org/10.5194/amt-17-3187-2024, https://doi.org/10.5194/amt-17-3187-2024, 2024
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Little noise in radial velocity Doppler lidar measurements can contribute to large errors in retrieved turbulence variables. In order to distinguish between plausible and erroneous measurements we developed new filter techniques that work independently of the choice of a specific threshold for the signal-to-noise ratio. The performance of these techniques is discussed both by means of assessing the filter results and by comparing retrieved turbulence variables versus independent measurements.
Luuk D. van der Valk, Miriam Coenders-Gerrits, Rolf W. Hut, Aart Overeem, Bas Walraven, and Remko Uijlenhoet
Atmos. Meas. Tech., 17, 2811–2832, https://doi.org/10.5194/amt-17-2811-2024, https://doi.org/10.5194/amt-17-2811-2024, 2024
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Microwave links, often part of mobile phone networks, can be used to measure rainfall along the link path by determining the signal loss caused by rainfall. We use high-frequency data of multiple microwave links to recreate commonly used sampling strategies. For time intervals up to 1 min, the influence of sampling strategies on estimated rainfall intensities is relatively little, while for intervals longer than 5–15 min, the sampling strategy can have significant influences on the estimates.
Martin Lainer, Killian P. Brennan, Alessandro Hering, Jérôme Kopp, Samuel Monhart, Daniel Wolfensberger, and Urs Germann
Atmos. Meas. Tech., 17, 2539–2557, https://doi.org/10.5194/amt-17-2539-2024, https://doi.org/10.5194/amt-17-2539-2024, 2024
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This study uses deep learning (the Mask R-CNN model) on drone-based photogrammetric data of hail on the ground to estimate hail size distributions (HSDs). Traditional hail sensors' limited areas complicate the full HSD retrieval. The HSD of a supercell event on 20 June 2021 is retrieved and contains > 18 000 hailstones. The HSD is compared to automatic hail sensor measurements and those of weather-radar-based MESHS. Investigations into ground hail melting are performed by five drone flights.
Andrea Camplani, Daniele Casella, Paolo Sanò, and Giulia Panegrossi
Atmos. Meas. Tech., 17, 2195–2217, https://doi.org/10.5194/amt-17-2195-2024, https://doi.org/10.5194/amt-17-2195-2024, 2024
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The paper describes a new machine-learning-based snowfall retrieval algorithm for Advanced Technology Microwave Sounder observations developed to retrieve high-latitude snowfall events. The main novelty of the approach is the radiometric characterization of the background surface at the time of the overpass, which is ancillary to the retrieval process. The algorithm shows a unique capability to retrieve snowfall in the environmental conditions typical of high latitudes.
Lusheng Liang, Wenying Su, Sergio Sejas, Zachary Eitzen, and Norman G. Loeb
Atmos. Meas. Tech., 17, 2147–2163, https://doi.org/10.5194/amt-17-2147-2024, https://doi.org/10.5194/amt-17-2147-2024, 2024
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This paper describes an updated process to obtain unfiltered radiation from CERES satellite instruments by incorporating the most recent developments in radiative transfer modeling and ancillary input datasets (e.g., realistic representation of land surface radiation and climatology of surface temperatures and aerosols) during the past 20 years. The resulting global mean of instantaneous SW and LW fluxes is changed by less than 0.5 W m−2 with regional differences as large as 2.0 W m−2.
Maximilian Graf, Andreas Wagner, Julius Polz, Llorenç Lliso, José Alberto Lahuerta, Harald Kunstmann, and Christian Chwala
Atmos. Meas. Tech., 17, 2165–2182, https://doi.org/10.5194/amt-17-2165-2024, https://doi.org/10.5194/amt-17-2165-2024, 2024
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Commercial microwave links (CMLs) can be used for rainfall retrieval. The detection of rainy periods in their attenuation time series is a crucial processing step. We investigate the usage of rainfall data from MSG SEVIRI for this task, compare this approach with existing methods, and introduce a novel combined approach. The results show certain advantages for SEVIRI-based methods, particularly for CMLs where existing methods perform poorly. Our novel combination yields the best performance.
Lieuwe G. Tilstra, Martin de Graaf, Victor J. H. Trees, Pavel Litvinov, Oleg Dubovik, and Piet Stammes
Atmos. Meas. Tech., 17, 2235–2256, https://doi.org/10.5194/amt-17-2235-2024, https://doi.org/10.5194/amt-17-2235-2024, 2024
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This paper introduces a new surface albedo climatology of directionally dependent Lambertian-equivalent reflectivity (DLER) observed by TROPOMI on the Sentinel-5 Precursor satellite. The database contains monthly fields of DLER for 21 wavelength bands at a relatively high spatial resolution of 0.125 by 0.125 degrees. The anisotropy of the surface reflection is handled by parameterisation of the viewing angle dependence.
Bing Cao and Alan Z. Liu
Atmos. Meas. Tech., 17, 2123–2146, https://doi.org/10.5194/amt-17-2123-2024, https://doi.org/10.5194/amt-17-2123-2024, 2024
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A narrow-band sodium lidar measures atmospheric waves but is limited to vertical variations. We propose to utilize phase shifts among observations from different laser beams to derive horizontal wave information. Two gravity wave packets were identified by this method. Both waves were found to interact with thin evanescent layers, partially reflected, but transmitted energy to higher altitudes. The method can detect more medium-frequency gravity waves for similar lidar systems worldwide.
Xiaozhen Xiong, Xu Liu, Robert Spurr, Ming Zhao, Qiguang Yang, Wan Wu, and Liqiao Lei
Atmos. Meas. Tech., 17, 1965–1978, https://doi.org/10.5194/amt-17-1965-2024, https://doi.org/10.5194/amt-17-1965-2024, 2024
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The term “hotspot” refers to the sharp increase in reflectance occurring when incident (solar) and reflected (viewing) directions coincide in the backscatter direction. The accurate simulation of hotspot directional signatures is important for many remote sensing applications, but current models typically require large values of computations to represent the hotspot accurately. This paper provides a numerically improved hotspot BRDF model that converges much faster and is used in VLIDORT.
Daniel Zawada, Kimberlee Dubé, Taran Warnock, Adam Bourassa, Susann Tegtmeier, and Douglas Degenstein
Atmos. Meas. Tech., 17, 1995–2010, https://doi.org/10.5194/amt-17-1995-2024, https://doi.org/10.5194/amt-17-1995-2024, 2024
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There remain large uncertainties in long-term changes of stratospheric–atmospheric temperatures. We have produced a time series of more than 20 years of satellite-based temperature measurements from the OSIRIS instrument in the upper–middle stratosphere. The dataset is publicly available and intended to be used for a better understanding of changes in stratospheric temperatures.
Matthieu Vernay, Matthieu Lafaysse, and Clotilde Augros
EGUsphere, https://doi.org/10.5194/egusphere-2024-668, https://doi.org/10.5194/egusphere-2024-668, 2024
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This paper provides a comprehensive evaluation of the quality of radar-based precipitation estimation in mountainous areas and presents a method to mitigate the main shortcomings identified. It then compares three different ensemble analysis methods that combine radar-based precipitation estimates with forecasts from an ensemble numerical weather prediction model.
Cited articles
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Short summary
The world's longest continuous total column ozone time series was initiated in 1926 at the Lichtklimatisches Observatorium (LKO), at Arosa, in the Swiss Alps. The measurements between Dobson and Brewer spectroradiometers have shown seasonal variations of the order of 2 %. The results of the study show that the consistency between the two instrument types can be significantly improved when the ozone cross-sections from Serdyuchenko et al. (2013) and the measured slit functions are used.
The world's longest continuous total column ozone time series was initiated in 1926 at the...
