Articles | Volume 10, issue 3
10 Mar 2017
Research article | 10 Mar 2017
Plume propagation direction determination with SO2 cameras
Angelika Klein et al.
No articles found.
Udo Frieß, Karin Kreher, Richard Querel, Holger Schmithüsen, Dan Smale, Rolf Weller, and Ulrich Platt
Reactive bromine compounds, emitted by the sea ice during polar spring, play an important role in the atmospheric chemistry of the coastal regions of Antarctica. We investigate the sources and impacts of reactive bromine in detail using many years of measurements at two Antarctic sites, located at opposite sides of the Antarctic continent. Using a multitude of meteorological observations, we were able to identify the main triggers and source regions for reactive bromine in Antarctica.
Maximilian Herrmann, Moritz Schöne, Christian Borger, Simon Warnach, Thomas Wagner, Ulrich Platt, and Eva Gutheil
Atmos. Chem. Phys., 22, 13495–13526,Short summary
Ozone depletion events (ODEs) are a common occurrence in the boundary layer during Arctic spring. Ozone is depleted by bromine species in an autocatalytic reaction cycle. Previous modeling studies assumed an infinite bromine source at the ground. An alternative emission scheme is presented in which a finite amount of bromide in the snow is tracked over time. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) is used to study ODEs in the Arctic from February to May 2019.
Thomas Wagner, Simon Warnach, Steffen Beirle, Nicole Bobrowski, Adrian Jost, Janis Puķīte, and Nicolas Theys
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
We investigate 3D effects of volcanic plumes on the retrieval results of satellite and ground based UV-vis observations. With its small ground pixels of 3.5 × 5.5 km2 the TROPOMI instrument can detect much smaller volcanic plumes than previous instruments. At the same time 3D effects become important. Especially the effect of horizontal photon paths can lead to a strong underestimation of the derived plume contents of up to > 50 %, which can be further increased for strong absorbers like SO2.
Henning Finkenzeller, Denis Pöhler, Martin Horbanski, Johannes Lampel, and Ulrich Platt
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
Optical resonators enhance the light path in compact instruments, thereby improving the sensitivity. Determining the established path length in the instrument is a prerequisite for the accurate determination of trace gas concentrations but can be a significant complication in the use of such resonators. Here we show two calibration techniques which are relatively simple and free of consumables, but still provide accurate calibrations. This facilitates the use of optical resonators.
M. Dolores Andrés Hernández, Andreas Hilboll, Helmut Ziereis, Eric Förster, Ovid O. Krüger, Katharina Kaiser, Johannes Schneider, Francesca Barnaba, Mihalis Vrekoussis, Jörg Schmidt, Heidi Huntrieser, Anne-Marlene Blechschmidt, Midhun George, Vladyslav Nenakhov, Theresa Harlass, Bruna A. Holanda, Jennifer Wolf, Lisa Eirenschmalz, Marc Krebsbach, Mira L. Pöhlker, Anna B. Kalisz Hedegaard, Linlu Mei, Klaus Pfeilsticker, Yangzhuoran Liu, Ralf Koppmann, Hans Schlager, Birger Bohn, Ulrich Schumann, Andreas Richter, Benjamin Schreiner, Daniel Sauer, Robert Baumann, Mariano Mertens, Patrick Jöckel, Markus Kilian, Greta Stratmann, Christopher Pöhlker, Monica Campanelli, Marco Pandolfi, Michael Sicard, José L. Gómez-Amo, Manuel Pujadas, Katja Bigge, Flora Kluge, Anja Schwarz, Nikos Daskalakis, David Walter, Andreas Zahn, Ulrich Pöschl, Harald Bönisch, Stephan Borrmann, Ulrich Platt, and John P. Burrows
Atmos. Chem. Phys., 22, 5877–5924,Short summary
EMeRGe provides a unique set of in situ and remote sensing airborne measurements of trace gases and aerosol particles along selected flight routes in the lower troposphere over Europe. The interpretation uses also complementary collocated ground-based and satellite measurements. The collected data help to improve the current understanding of the complex spatial distribution of trace gases and aerosol particles resulting from mixing, transport, and transformation of pollution plumes over Europe.
Jan-Lukas Tirpitz, Udo Frieß, Robert Spurr, and Ulrich Platt
Atmos. Meas. Tech., 15, 2077–2098,Short summary
MAX-DOAS is a widely used measurement technique for the remote detection of atmospheric aerosol and trace gases. It relies on the analysis of ultra-violet and visible radiation spectra of skylight. To date, information contained in the skylight's polarisation state has not been utilised. On the basis of synthetic data, we carried out sensitivity analyses to assess the potential of polarimetry for MAX-DOAS applications.
Leon Kuhn, Jonas Kuhn, Thomas Wagner, and Ulrich Platt
Atmos. Meas. Tech., 15, 1395–1414,Short summary
We present a novel instrument for imaging measurements of NO2 with high spatiotemporal resolution based on gas correlation spectroscopy, called the GCS NO2 camera. The instrument works by placing two gas cells (cuvettes) in front of two photosensor arrays, one filled with air and one filled with a high concentration of NO2, acting as a non-dispersive spectral filter. NO2 images are then generated on the basis of the signal ratio of the two channels in the spectral region of 430–445 nm.
Jonas Kuhn, Nicole Bobrowski, Thomas Wagner, and Ulrich Platt
Atmos. Meas. Tech., 14, 7873–7892,Short summary
We propose spectrograph implementations using Fabry–Pérot interferometers for atmospheric trace gas remote sensing. Compared with widely used grating spectrographs, we find substantial light throughput and mobility advantages for high resolving powers. Besides lowering detection limits and increasing the spatial and temporal resolution of many atmospheric trace gas measurements, this approach might enable remote sensing of further important gases such as tropospheric OH radicals.
Ulrich Platt, Thomas Wagner, Jonas Kuhn, and Thomas Leisner
Atmos. Meas. Tech., 14, 6867–6883,Short summary
Absorption spectroscopy of scattered sunlight is extremely useful for the analysis of atmospheric trace gas distributions. A central parameter for the achievable sensitivity of spectroscopic instruments is the light throughput, which can be enhanced in a number of ways. We present new ideas and considerations of how instruments could be optimized. Particular emphasis is on arrays of massively parallel instruments. Such arrays can reduce the size and weight of instruments by orders of magnitude.
Alexandra Gutmann, Nicole Bobrowski, Marcello Liotta, and Thorsten Hoffmann
Atmos. Meas. Tech., 14, 6395–6406,Short summary
Motivated by a special interest in bromine chemistry in volcanic plumes, the study presented here describes a new method for the quantitative collection of gaseous hydrogen bromide in gas diffusion denuders. The hydrogen bromide reacted during sampling with appropriate epoxides applied to the denuder walls. The denuder sampling assembly was successfully deployed in the volcanic plume of Masaya volcano, Nicaragua.
Florian Dinger, Timo Kleinbek, Steffen Dörner, Nicole Bobrowski, Ulrich Platt, Thomas Wagner, Martha Ibarra, and Eveling Espinoza
Atmos. Chem. Phys., 21, 9367–9404,Short summary
Monitoring magnitude or chemical composition of volcanic gas emissions can help to forecast volcanic eruptions and provides empirical data on the impact of volcanoes on the chemistry in the local and global atmosphere. This study reports and discusses continuous time series of the sulfur and bromine emission fluxes of Masaya from 2014 to 2020. We observed an annual cyclicity in the BrO / SO2 molar ratio, possibly caused by the annual variability in the atmospheric humidity.
Bo Galle, Santiago Arellano, Nicole Bobrowski, Vladimir Conde, Tobias P. Fischer, Gustav Gerdes, Alexandra Gutmann, Thorsten Hoffmann, Ima Itikarai, Tomas Krejci, Emma J. Liu, Kila Mulina, Scott Nowicki, Tom Richardson, Julian Rüdiger, Kieran Wood, and Jiazhi Xu
Atmos. Meas. Tech., 14, 4255–4277,Short summary
Measurements of volcanic gases are important for geophysical research, risk assessment and environmental impact studies. Some gases, like SO2 and BrO, may be studied from the ground at a safe distance using remote sensing techniques. Many other gases require in situ access to the gas plume. Here, a drone may be an attractive alternative. This paper describes a drone specially adapted for volcanic gas studies and demonstrates its use in a field campaign at Manam volcano in Papua New Guinea.
Maximilian Herrmann, Holger Sihler, Udo Frieß, Thomas Wagner, Ulrich Platt, and Eva Gutheil
Atmos. Chem. Phys., 21, 7611–7638,Short summary
Time-dependent 3D numerical simulations of tropospheric bromine release and ozone depletion events (ODEs) in the Arctic polar spring of 2009 are compared to observations. Simulation results agree well with the observations at both Utqiaġvik, Alaska, and at Summit, Greenland. In a parameter study, different settings for the bromine release mechanism are evaluated. An enhancement of the bromine release mechanism improves the agreement regarding the occurrence of ODEs with the observations.
Santiago Arellano, Bo Galle, Fredy Apaza, Geoffroy Avard, Charlotte Barrington, Nicole Bobrowski, Claudia Bucarey, Viviana Burbano, Mike Burton, Zoraida Chacón, Gustavo Chigna, Christian Joseph Clarito, Vladimir Conde, Fidel Costa, Maarten De Moor, Hugo Delgado-Granados, Andrea Di Muro, Deborah Fernandez, Gustavo Garzón, Hendra Gunawan, Nia Haerani, Thor H. Hansteen, Silvana Hidalgo, Salvatore Inguaggiato, Mattias Johansson, Christoph Kern, Manne Kihlman, Philippe Kowalski, Pablo Masias, Francisco Montalvo, Joakim Möller, Ulrich Platt, Claudia Rivera, Armando Saballos, Giuseppe Salerno, Benoit Taisne, Freddy Vásconez, Gabriela Velásquez, Fabio Vita, and Mathieu Yalire
Earth Syst. Sci. Data, 13, 1167–1188,Short summary
This study presents a dataset of volcanic sulfur dioxide (SO2) emissions from 2005–2017. Measurements were obtained by Network for Observation of Volcanic and Atmospheric Change (NOVAC) scanning differential optical absorption spectrometer (ScanDOAS) instruments at 32 volcanoes and processed using a standardized procedure. We show statistics of volcanic gas emissions under a variety of conditions and compare them with averages derived from measurements from space and historical inventories.
Julian Rüdiger, Alexandra Gutmann, Nicole Bobrowski, Marcello Liotta, J. Maarten de Moor, Rolf Sander, Florian Dinger, Jan-Lukas Tirpitz, Martha Ibarra, Armando Saballos, María Martínez, Elvis Mendoza, Arnoldo Ferrufino, John Stix, Juan Valdés, Jonathan M. Castro, and Thorsten Hoffmann
Atmos. Chem. Phys., 21, 3371–3393,Short summary
We present an innovative approach to study halogen chemistry in the plume of Masaya volcano in Nicaragua. An unique data set was collected using multiple techniques, including drones. These data enabled us to determine the fraction of activation of the respective halogens at various plume ages, where in-mixing of ambient air causes chemical reactions. An atmospheric chemistry box model was employed to further examine the field results and help our understanding of volcanic plume chemistry.
Christopher Fuchs, Jonas Kuhn, Nicole Bobrowski, and Ulrich Platt
Atmos. Meas. Tech., 14, 295–307,Short summary
We present first measurements of volcanic SO2 emissions with a novel imaging technique for atmospheric trace gases in the UV and visible spectral range. Periodic spectral Fabry–Pérot interferometer transmission features are matched to differential absorption cross sections of the investigated trace gas, yielding high selectivity and sensitivity. The technique can be extended to measure many other trace gases with high spatio-temporal resolution.
Jan-Lukas Tirpitz, Udo Frieß, François Hendrick, Carlos Alberti, Marc Allaart, Arnoud Apituley, Alkis Bais, Steffen Beirle, Stijn Berkhout, Kristof Bognar, Tim Bösch, Ilya Bruchkouski, Alexander Cede, Ka Lok Chan, Mirjam den Hoed, Sebastian Donner, Theano Drosoglou, Caroline Fayt, Martina M. Friedrich, Arnoud Frumau, Lou Gast, Clio Gielen, Laura Gomez-Martín, Nan Hao, Arjan Hensen, Bas Henzing, Christian Hermans, Junli Jin, Karin Kreher, Jonas Kuhn, Johannes Lampel, Ang Li, Cheng Liu, Haoran Liu, Jianzhong Ma, Alexis Merlaud, Enno Peters, Gaia Pinardi, Ankie Piters, Ulrich Platt, Olga Puentedura, Andreas Richter, Stefan Schmitt, Elena Spinei, Deborah Stein Zweers, Kimberly Strong, Daan Swart, Frederik Tack, Martin Tiefengraber, René van der Hoff, Michel van Roozendael, Tim Vlemmix, Jan Vonk, Thomas Wagner, Yang Wang, Zhuoru Wang, Mark Wenig, Matthias Wiegner, Folkard Wittrock, Pinhua Xie, Chengzhi Xing, Jin Xu, Margarita Yela, Chengxin Zhang, and Xiaoyi Zhao
Atmos. Meas. Tech., 14, 1–35,Short summary
Multi-axis differential optical absorption spectroscopy (MAX-DOAS) is a ground-based remote sensing measurement technique that derives atmospheric aerosol and trace gas vertical profiles from skylight spectra. In this study, consistency and reliability of MAX-DOAS profiles are assessed by applying nine different evaluation algorithms to spectral data recorded during an intercomparison campaign in the Netherlands and by comparing the results to colocated supporting observations.
Karin Kreher, Michel Van Roozendael, Francois Hendrick, Arnoud Apituley, Ermioni Dimitropoulou, Udo Frieß, Andreas Richter, Thomas Wagner, Johannes Lampel, Nader Abuhassan, Li Ang, Monica Anguas, Alkis Bais, Nuria Benavent, Tim Bösch, Kristof Bognar, Alexander Borovski, Ilya Bruchkouski, Alexander Cede, Ka Lok Chan, Sebastian Donner, Theano Drosoglou, Caroline Fayt, Henning Finkenzeller, David Garcia-Nieto, Clio Gielen, Laura Gómez-Martín, Nan Hao, Bas Henzing, Jay R. Herman, Christian Hermans, Syedul Hoque, Hitoshi Irie, Junli Jin, Paul Johnston, Junaid Khayyam Butt, Fahim Khokhar, Theodore K. Koenig, Jonas Kuhn, Vinod Kumar, Cheng Liu, Jianzhong Ma, Alexis Merlaud, Abhishek K. Mishra, Moritz Müller, Monica Navarro-Comas, Mareike Ostendorf, Andrea Pazmino, Enno Peters, Gaia Pinardi, Manuel Pinharanda, Ankie Piters, Ulrich Platt, Oleg Postylyakov, Cristina Prados-Roman, Olga Puentedura, Richard Querel, Alfonso Saiz-Lopez, Anja Schönhardt, Stefan F. Schreier, André Seyler, Vinayak Sinha, Elena Spinei, Kimberly Strong, Frederik Tack, Xin Tian, Martin Tiefengraber, Jan-Lukas Tirpitz, Jeroen van Gent, Rainer Volkamer, Mihalis Vrekoussis, Shanshan Wang, Zhuoru Wang, Mark Wenig, Folkard Wittrock, Pinhua H. Xie, Jin Xu, Margarita Yela, Chengxin Zhang, and Xiaoyi Zhao
Atmos. Meas. Tech., 13, 2169–2208,Short summary
In September 2016, 36 spectrometers from 24 institutes measured a number of key atmospheric pollutants during an instrument intercomparison campaign (CINDI-2) at Cabauw, the Netherlands. Here we report on the outcome of this intercomparison exercise. The three major goals were to characterise the differences between the participating instruments, to define a robust methodology for performance assessment, and to contribute to the harmonisation of the measurement settings and retrieval methods.
Ulrich Platt and Jonas Kuhn
Atmos. Meas. Tech., 12, 6259–6272,Short summary
Measurements of atmospheric trace gases by absorption spectroscopy are frequently supported by recording the amount of trace gas in absorption cells. These are typically small glass (or quartz) cylinders containing the gas to be studied. Here we show in the example of NO2-absorption cells that the effective amount of gas seen by the instrument can deviate greatly from expected values (by orders of magnitude in severe cases). Some suggestions for improving the situation are discussed.
Maximilian Herrmann, Le Cao, Holger Sihler, Ulrich Platt, and Eva Gutheil
Atmos. Chem. Phys., 19, 10161–10190,Short summary
The oscillations of tropospheric ODEs in the Arctic spring is studied numerically. After the termination of an ODE, the reactive bromine is deposited onto aerosols/the snow surface, and the ozone may regenerate. The replenished ozone is available for the next autocatalytic bromine release, leading to the oscillation of an ODE. Its dependence on the NOx mixing ratio, the inversion layer strength, the ambient temperature, the aerosol density, and the solar radiation is investigated.
Jan-Marcus Nasse, Philipp G. Eger, Denis Pöhler, Stefan Schmitt, Udo Frieß, and Ulrich Platt
Atmos. Meas. Tech., 12, 4149–4169,Short summary
We present several changes to the setup of long-path differential optical absorption spectroscopy (LP-DOAS) instruments, including the application of a laser-driven light source, a modified coupling of the measurement signal between components, improved stray-light suppression, and better signal homogenization measures. These changes reduce detection limits of typical trace-gas species by a factor of 3–4 compared to previous setups and enable automated long-term observations in Antarctica.
Martin Horbanski, Denis Pöhler, Johannes Lampel, and Ulrich Platt
Atmos. Meas. Tech., 12, 3365–3381,Short summary
ICAD allows a precise in situ measurement of gases like NO2 in a relatively simple and compact setup. The main advantage in comparison to most other optical methods is that it does not require a stable total light intensity. This allows a simpler and mobile instrument setup and additionally it features no observed cross-interferences. We validated the high quality for an ICAD NO2 instrument in different inter-comparisons with a detection limit of 0.02 ppbv.
Florian Dinger, Stefan Bredemeyer, Santiago Arellano, Nicole Bobrowski, Ulrich Platt, and Thomas Wagner
Solid Earth, 10, 725–740,Short summary
Evidence for tidal impacts on volcanism have been gathered by numerous empirical studies. This paper elucidates whether a causal link from the tidal forces to a variation in the volcanic degassing can be traced analytically. We model the response of a simplified magmatic system to the local tidal gravity variations, find that the tide-induced dynamics may significantly alter the bubble coalescence rate, and discuss the consequences for volcanic degassing behaviour.
Jonas Kuhn, Ulrich Platt, Nicole Bobrowski, and Thomas Wagner
Atmos. Meas. Tech., 12, 735–747,Short summary
We study a novel remote-sensing technique for atmospheric trace gases absorbing in the UV and visible spectral range. Using Fabry–Perot interferometers with a spectral transmission matched to the trace gas's spectral absorption allows for imaging trace gases with high sensitivity and selectivity. The thereby achieved high spatio-temporal resolution enables the study of small-scale and dynamic processes in the atmosphere. We present sample calculations and a proof-of-concept study.
Jorge Saturno, Florian Ditas, Marloes Penning de Vries, Bruna A. Holanda, Mira L. Pöhlker, Samara Carbone, David Walter, Nicole Bobrowski, Joel Brito, Xuguang Chi, Alexandra Gutmann, Isabella Hrabe de Angelis, Luiz A. T. Machado, Daniel Moran-Zuloaga, Julian Rüdiger, Johannes Schneider, Christiane Schulz, Qiaoqiao Wang, Manfred Wendisch, Paulo Artaxo, Thomas Wagner, Ulrich Pöschl, Meinrat O. Andreae, and Christopher Pöhlker
Atmos. Chem. Phys., 18, 10391–10405,Short summary
This study uses satellite observations to track volcanic emissions in eastern Congo and their subsequent transport across the Atlantic Ocean into the Amazon Basin. Aircraft and ground-based observations are used to characterize the influence of volcanogenic aerosol on the chemical and microphysical properties of Amazonian aerosols. Further, this work is an illustrative example of the conditions and dynamics driving the transatlantic transport of African emissions to South America.
Stephen Broccardo, Klaus-Peter Heue, David Walter, Christian Meyer, Alexander Kokhanovsky, Ronald van der A, Stuart Piketh, Kristy Langerman, and Ulrich Platt
Atmos. Meas. Tech., 11, 2797–2819,Short summary
Measurements of nitrogen dioxide, known to originate from industrial and automotive combustion sources, have been made from space for two decades. Successive generations of instrument bring improvements in ground-pixel resolution; however features in the atmosphere are known to be smaller than what the satellites can resolve. Measurements of urban and industrial areas using a high-resolution airborne instrument allow the impact of the satellite's relatively low resolution to be evaluated.
Julian Rüdiger, Jan-Lukas Tirpitz, J. Maarten de Moor, Nicole Bobrowski, Alexandra Gutmann, Marco Liuzzo, Martha Ibarra, and Thorsten Hoffmann
Atmos. Meas. Tech., 11, 2441–2457,Short summary
Volcanic gas emission studies are important for monitoring active volcanoes, obtaining insights into subsurface processes and opening up an interesting domain for atmospheric chemistry investigations. Using an unmanned aerial vehicle, commonly called a drone, we were able to study various volcanic gases at sites which are typically too dangerous to access otherwise. The use of drones for volcano monitoring and gas measurements in harsh environments was successfully assessed.
David W. T. Griffith, Denis Pöhler, Stefan Schmitt, Samuel Hammer, Sanam N. Vardag, and Ulrich Platt
Atmos. Meas. Tech., 11, 1549–1563,Short summary
Measurements of atmospheric trace gases over an open path complement in situ measurements by spatial averaging. This paper describes the first open-path measurements of CO2, CH4 and other trace gases by near-infrared Fourier transform spectroscopy. The measurements were made in Heidelberg, Germany, for 4 months in 2014 over a 1.5 km path and compared to in situ measurements made at one end of the path. The experiment setup and methods (and the comparisons of open path to in situ) are described.
Florian Dinger, Nicole Bobrowski, Simon Warnach, Stefan Bredemeyer, Silvana Hidalgo, Santiago Arellano, Bo Galle, Ulrich Platt, and Thomas Wagner
Solid Earth, 9, 247–266,Short summary
We monitored the bromine monoxide-to-sulfur dioxide molar ratio in the effusive gas plume of Cotopaxi volcano in order to gain insight into the geological processes which control the pressure regime of the volcanic system. We observed a conspicuous periodic pattern with a periodicity of about 2 weeks, which significantly correlates with the Earth tidal forcing. Our results support a possible Earth tidal impact on volcanic activity, in particular for the Cotopaxi eruption 2015.
Christoph Kleinschmitt, Olivier Boucher, and Ulrich Platt
Atmos. Chem. Phys., 18, 2769–2786,Short summary
We use a state-of-the-art stratospheric aerosol model to study geoengineering through stratospheric sulfur injections. We find that the efficiency may decrease more drastically for larger injections than previously estimated and that injections at higher altitude are not more effective. This study may provide additional evidence that this proposed geoengineering technique is still more complicated, probably less effective, and may implicate stronger side effects than initially thought.
Johannes Lampel, Johannes Zielcke, Stefan Schmitt, Denis Pöhler, Udo Frieß, Ulrich Platt, and Thomas Wagner
Atmos. Chem. Phys., 18, 1671–1683,Short summary
Previous publications on the absorptions of the oxygen dimer O2–O2 (or short: O4) list absorption peaks at 328 nm and 419 nm, for which no spectrally resolved literature cross sections are available. As these absorptions potentially influence the spectral retrieval of various other trace gases, their shape and magnitude need to be quantified. We approximate the absorption peaks at 328 nm and 419 nm by their respective neighboring absorption peaks to estimate their magnitude and peak wavelength.
Johannes Lampel, Yang Wang, Andreas Hilboll, Steffen Beirle, Holger Sihler, Janis Puķīte, Ulrich Platt, and Thomas Wagner
Atmos. Meas. Tech., 10, 4819–4831,Short summary
Experience of differential atmospheric absorption spectroscopy (DOAS) shows that a spectral shift between measurement and reference spectrum is frequently required in order to achieve optimal fit results. The shift is often attributed to temporal instabilities of the instrument but implicitly solved the problem of the tilt effect discussed in this paper. The tilt effect results from the finite resolution of the measurements and amounts to 2 pm for the example data set.
Christoph Kleinschmitt, Olivier Boucher, Slimane Bekki, François Lott, and Ulrich Platt
Geosci. Model Dev., 10, 3359–3378,Short summary
Stratospheric aerosols play an important role in the climate system by affecting the Earth's radiative budget. In this article we present the newly developed LMDZ-S3A model and assess its performance against observations in periods of low and high aerosol loading. The model may serve as a tool to study the climate impacts of volcanic eruptions, as well as the deliberate injection of aerosols into the stratosphere, which has been proposed as a method of geoengineering to abate global warming.
William R. Simpson, Peter K. Peterson, Udo Frieß, Holger Sihler, Johannes Lampel, Ulrich Platt, Chris Moore, Kerri Pratt, Paul Shepson, John Halfacre, and Son V. Nghiem
Atmos. Chem. Phys., 17, 9291–9309,Short summary
We investigated Arctic atmospheric bromine chemistry during March–April 2012 to improve understanding of the role of sea ice and cracks in sea ice (leads) in this phenomenon. We find that leads vertically redistribute reactive bromine but that open/re-freezing leads are not major direct reactive halogen sources. Surface ozone depletion affects the vertical distribution and amount of reactive halogens, and aerosol particles are necessary but not sufficient to maintain reactive bromine aloft.
Peter K. Peterson, Denis Pöhler, Holger Sihler, Johannes Zielcke, Stephan General, Udo Frieß, Ulrich Platt, William R. Simpson, Son V. Nghiem, Paul B. Shepson, Brian H. Stirm, Suresh Dhaniyala, Thomas Wagner, Dana R. Caulton, Jose D. Fuentes, and Kerri A. Pratt
Atmos. Chem. Phys., 17, 7567–7579,Short summary
High-spatial-resolution aircraft measurements in the Arctic showed the sustained transport of reactive bromine in a lofted layer via heterogeneous reactions on aerosol particles. This process provides an explanation for free tropospheric reactive bromine and the significant spatial extent of satellite-observed bromine monoxide. The knowledge gained herein improves our understanding of the fate and transport of atmospheric pollutants in the Arctic.
Holger Sihler, Peter Lübcke, Rüdiger Lang, Steffen Beirle, Martin de Graaf, Christoph Hörmann, Johannes Lampel, Marloes Penning de Vries, Julia Remmers, Ed Trollope, Yang Wang, and Thomas Wagner
Atmos. Meas. Tech., 10, 881–903,Short summary
This paper presents the independent and simple IFR method to retrieve the FOV of an instrument, i.e. the two-dimensional sensitivity distribution. IFR relies on correlated measurements featuring a higher spatial resolution and was applied to two satellite instruments, GOME-2 and OMI, and a DOAS instrument integrated in an SO2 camera. Our results confirm the commonly applied FOV distributions. IFR is applicable for verification exercises as well as degradation monitoring in the field.
Nga Lee Ng, Steven S. Brown, Alexander T. Archibald, Elliot Atlas, Ronald C. Cohen, John N. Crowley, Douglas A. Day, Neil M. Donahue, Juliane L. Fry, Hendrik Fuchs, Robert J. Griffin, Marcelo I. Guzman, Hartmut Herrmann, Alma Hodzic, Yoshiteru Iinuma, José L. Jimenez, Astrid Kiendler-Scharr, Ben H. Lee, Deborah J. Luecken, Jingqiu Mao, Robert McLaren, Anke Mutzel, Hans D. Osthoff, Bin Ouyang, Benedicte Picquet-Varrault, Ulrich Platt, Havala O. T. Pye, Yinon Rudich, Rebecca H. Schwantes, Manabu Shiraiwa, Jochen Stutz, Joel A. Thornton, Andreas Tilgner, Brent J. Williams, and Rahul A. Zaveri
Atmos. Chem. Phys., 17, 2103–2162,Short summary
Oxidation of biogenic volatile organic compounds by NO3 is an important interaction between anthropogenic and natural emissions. This review results from a June 2015 workshop and includes the recent literature on kinetics, mechanisms, organic aerosol yields, and heterogeneous chemistry; advances in analytical instrumentation; the current state NO3-BVOC chemistry in atmospheric models; and critical needs for future research in modeling, field observations, and laboratory studies.
Johannes Lampel, Denis Pöhler, Oleg L. Polyansky, Aleksandra A. Kyuberis, Nikolai F. Zobov, Jonathan Tennyson, Lorenzo Lodi, Udo Frieß, Yang Wang, Steffen Beirle, Ulrich Platt, and Thomas Wagner
Atmos. Chem. Phys., 17, 1271–1295,Short summary
Water vapour is known to absorb radiation from the microwave region to the blue part of the visible spectrum. Ab initio approaches to model individual absorption lines of the gaseous water molecule predict absorption lines until its dissociation limit at 243 nm. We present first evidence of water vapour absorption near 363 nm from field measurements using data from multi-axis differential optical absorption spectroscopy (MAX-DOAS) and long-path (LP)-DOAS measurements.
André Butz, Anna Solvejg Dinger, Nicole Bobrowski, Julian Kostinek, Lukas Fieber, Constanze Fischerkeller, Giovanni Bruno Giuffrida, Frank Hase, Friedrich Klappenbach, Jonas Kuhn, Peter Lübcke, Lukas Tirpitz, and Qiansi Tu
Atmos. Meas. Tech., 10, 1–14,Short summary
Remote sensing of the gaseous composition of non-eruptive, passively degassing volcanic plumes can be a tool for volcano monitoring. Here, we report on a field study that demonstrates the feasibility of remotely measuring the volcanic enhancements of carbon dioxide, hydrogen fluoride, hydrogen chloride, sulfur dioxide, and bromine monoxide in the plume of Mt. Etna using portable spectroscopic instrumentation sampling the plume several kilometers downwind of the source.
Peter Lübcke, Johannes Lampel, Santiago Arellano, Nicole Bobrowski, Florian Dinger, Bo Galle, Gustavo Garzón, Silvana Hidalgo, Zoraida Chacón Ortiz, Leif Vogel, Simon Warnach, and Ulrich Platt
Atmos. Meas. Tech., 9, 5677–5698,Short summary
We evaluated spectra from a scanning spectrometer network for the monitoring of volcanic gas emissions using a modelled background spectrum. Statistical methods were applied in order to improve the quality of the spectroscopic evaluation. We used this technique to assess the robustness of standard retrievals at two volcanos: Nevado del Ruiz (Colombia) and Tungurahua (Ecuador).
Christoph Hörmann, Holger Sihler, Steffen Beirle, Marloes Penning de Vries, Ulrich Platt, and Thomas Wagner
Atmos. Chem. Phys., 16, 13015–13034,Short summary
We present 10 years of bromine monoxide (BrO) satellite observations by the Ozone Monitoring Instrument (OMI) over the Rann of Kutch salt marsh. The measurements reveal a typical seasonal cycle of BrO with maximum concentrations during April/May. The results indicate that the Rann of Kutch is probably one of the strongest natural point sources of reactive bromine compounds outside the polar regions and is thought to have a significant impact on local and regional ozone chemistry.
Erna Frins, Reza Shaiganfar, Ulrich Platt, and Thomas Wagner
Atmos. Meas. Tech. Discuss.,
Revised manuscript has not been submittedShort summary
Standard methods like in-situ measurements can hardly register NOx (= NO + NO2) emissions from aircrafts during take-off, when engines run at high load and thus an important amount of fuel is consumed and most of the harmful emissions are produced . The goal of this work is to show that it is possible to measure aircraft emissions generated during take-off (and initial part of the climb) by a remote spectroscopic method like automobile – based – Differential Optical Absorption Spectroscopy (DOAS).
Le Cao, Ulrich Platt, Chenggang Wang, Nianwen Cao, and Qing Qin
Atmos. Chem. Phys. Discuss.,
Revised manuscript has not been submittedShort summary
A snowpack module which represents the mass transfer between the ambient air and the snowpack is implemented in a box model, aiming to clarify the influences of the snowpack on the ozone depletion events (ODEs) and the associated bromine explosion in the springtime of Arctic. The size of snow grains, volume fraction of the liquid-like layer (LLL), and the rate of the mass exchange between the snow interstitial air and the snow particles are shown to be critical parameters.
N. Sobanski, M. J. Tang, J. Thieser, G. Schuster, D. Pöhler, H. Fischer, W. Song, C. Sauvage, J. Williams, J. Fachinger, F. Berkes, P. Hoor, U. Platt, J. Lelieveld, and J. N. Crowley
Atmos. Chem. Phys., 16, 4867–4883,Short summary
The nitrate radical (NO3) is an important nocturnal oxidant. By measuring NO3, its precursors (nitrogen dioxide and ozone) and several trace gases with which it reacts, we examined the chemical and meteorological factors influencing the lifetime of NO3 at a semi-rural mountain site. Unexpectedly long lifetimes, approaching 1 h, were observed on several nights and were associated with a low-lying residual layer. We discuss the role of other reactions that convert NO2 to NO3.
J. Lampel, D. Pöhler, J. Tschritter, U. Frieß, and U. Platt
Atmos. Meas. Tech., 8, 4329–4346,Short summary
In recent updates of the HITRAN water vapour H2O spectroscopic compilation covering the blue spectral region (here 394–-480 nm) significant changes for the absorption bands at 416 and 426 nm were reported. In order to investigate the consistency of the different cross sections calculated from these compilations, H2O vapour column density ratios for different spectral intervals were retrieved from long-path and multi-axis differential optical absorption spectroscopy measurements.
K. D. Custard, C. R. Thompson, K. A. Pratt, P B. Shepson, J. Liao, L. G. Huey, J. J. Orlando, A. J. Weinheimer, E. Apel, S. R. Hall, F. Flocke, L. Mauldin, R. S. Hornbrook, D. Pöhler, S. General, J. Zielcke, W. R. Simpson, U. Platt, A. Fried, P. Weibring, B. C. Sive, K. Ullmann, C. Cantrell, D. J. Knapp, and D. D. Montzka
Atmos. Chem. Phys., 15, 10799–10809,
J. Lampel, U. Frieß, and U. Platt
Atmos. Meas. Tech., 8, 3767–3787,Short summary
In remote sensing applications, such as differential optical absorption spectroscopy (DOAS), atmospheric scattering processes need to be considered. Inelastic scattering on air molecules can lead to filling-in of absorption lines. The contribution of rotational Raman scattering is typically corrected for. The magnitude of vibrational Raman scattering (VRS) is known from theory and agrees with our first DOAS observations of this effect. Its impact on trace-gas measurements of NO2 is discussed.
J. Gliß, N. Bobrowski, L. Vogel, D. Pöhler, and U. Platt
Atmos. Chem. Phys., 15, 5659–5681,
P. K. Peterson, W. R. Simpson, K. A. Pratt, P. B. Shepson, U. Frieß, J. Zielcke, U. Platt, S. J. Walsh, and S. V. Nghiem
Atmos. Chem. Phys., 15, 2119–2137,Short summary
We developed methods to measure the vertical distribution of bromine monoxide, a gas that oxidizes pollutants, above sea ice based upon MAX-DOAS observations from Barrow, Alaska, and find that atmospheric stability exerts a strong control on BrO's vertical distribution. Specifically, more stable (temperature inversion) situations result in BrO being closer to the ground while more neutral (not inverted) atmospheres allow BrO to ascend further aloft and grow to larger column abundance.
J. Kuhn, N. Bobrowski, P. Lübcke, L. Vogel, and U. Platt
Atmos. Meas. Tech., 7, 3705–3715,
S. General, D. Pöhler, H. Sihler, N. Bobrowski, U. Frieß, J. Zielcke, M. Horbanski, P. B. Shepson, B. H. Stirm, W. R. Simpson, K. Weber, C. Fischer, and U. Platt
Atmos. Meas. Tech., 7, 3459–3485,
K.-P. Heue, H. Riede, D. Walter, C. A. M. Brenninkmeijer, T. Wagner, U. Frieß, U. Platt, A. Zahn, G. Stratmann, and H. Ziereis
Atmos. Chem. Phys., 14, 6621–6642,
P. Lübcke, N. Bobrowski, S. Arellano, B. Galle, G. Garzón, L. Vogel, and U. Platt
Solid Earth, 5, 409–424,
S. Bleicher, J. C. Buxmann, R. Sander, T. P. Riedel, J. A. Thornton, U. Platt, and C. Zetzsch
Atmos. Chem. Phys. Discuss.,
Revised manuscript has not been submitted
L. Cao, H. Sihler, U. Platt, and E. Gutheil
Atmos. Chem. Phys., 14, 3771–3787,
C. Liu, S. Beirle, T. Butler, P. Hoor, C. Frankenberg, P. Jöckel, M. Penning de Vries, U. Platt, A. Pozzer, M. G. Lawrence, J. Lelieveld, H. Tost, and T. Wagner
Atmos. Chem. Phys., 14, 1717–1732,
D. J. Hoch, J. Buxmann, H. Sihler, D. Pöhler, C. Zetzsch, and U. Platt
Atmos. Meas. Tech., 7, 199–214,
R. M. Varma, S. M. Ball, T. Brauers, H.-P. Dorn, U. Heitmann, R. L. Jones, U. Platt, D. Pöhler, A. A. Ruth, A. J. L. Shillings, J. Thieser, A. Wahner, and D. S. Venables
Atmos. Meas. Tech., 6, 3115–3130,
C. Hörmann, H. Sihler, N. Bobrowski, S. Beirle, M. Penning de Vries, U. Platt, and T. Wagner
Atmos. Chem. Phys., 13, 4749–4781,
H.-P. Dorn, R. L. Apodaca, S. M. Ball, T. Brauers, S. S. Brown, J. N. Crowley, W. P. Dubé, H. Fuchs, R. Häseler, U. Heitmann, R. L. Jones, A. Kiendler-Scharr, I. Labazan, J. M. Langridge, J. Meinen, T. F. Mentel, U. Platt, D. Pöhler, F. Rohrer, A. A. Ruth, E. Schlosser, G. Schuster, A. J. L. Shillings, W. R. Simpson, J. Thieser, R. Tillmann, R. Varma, D. S. Venables, and A. Wahner
Atmos. Meas. Tech., 6, 1111–1140,
K. Großmann, U. Frieß, E. Peters, F. Wittrock, J. Lampel, S. Yilmaz, J. Tschritter, R. Sommariva, R. von Glasow, B. Quack, K. Krüger, K. Pfeilsticker, and U. Platt
Atmos. Chem. Phys., 13, 3363–3378,
P. Lübcke, N. Bobrowski, S. Illing, C. Kern, J. M. Alvarez Nieves, L. Vogel, J. Zielcke, H. Delgado Granados, and U. Platt
Atmos. Meas. Tech., 6, 677–696,
Related subject area
Subject: Gases | Technique: Remote Sensing | Topic: Data Processing and Information RetrievalHarmonized retrieval of middle atmospheric ozone from two microwave radiometers in SwitzerlandAssessment of the error budget for stratospheric ozone profiles retrieved from OMPS limb scatter measurementsAlgorithm theoretical basis for ozone and sulfur dioxide retrievals from DSCOVR EPICImpact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 2: Impact on NO2 retrieval and mitigation strategiesTropospheric ozone retrieval by a combination of TROPOMI/S5P measurements with BASCOE assimilated dataA new machine-learning-based analysis for improving satellite-retrieved atmospheric composition data: OMI SO2 as an exampleComplementing XCO2 imagery with ground-based CO2 and 14CO2 measurements to monitor CO2 emissions from fossil fuels on a regional to local scaleOn the potential of a neural-network-based approach for estimating XCO2 from OCO-2 measurementsThe Space Carbon Observatory (SCARBO) concept: assessment of XCO2 and XCH4 retrieval performanceImproved retrieval of SO2 plume height from TROPOMI using an iterative Covariance-Based Retrieval AlgorithmImpact of instrumental line shape characterization on ozone monitoring by FTIR spectrometryRetrieval of Atmospheric CFC-11 and CFC-12 from High-resolution FTIR Observations at Hefei and Comparisons with Satellite DataSynergetic use of IASI profile and TROPOMI total-column level 2 methane retrieval productsComment on “Synergetic use of IASI profile and TROPOMI total-column level 2 methane retrieval products” by Schneider et al. (2022)Evaluation of the methane full-physics retrieval applied to TROPOMI ocean sun glint measurementsAn optimal estimation-based retrieval of upper atmospheric oxygen airglow and temperature from SCIAMACHY limb observationsOzone Monitoring Instrument (OMI) collection 4: establishing a 17-year-long series of detrended level-1b dataImpact of 3D cloud structures on the atmospheric trace gas products from UV–Vis sounders – Part 3: Bias estimate using synthetic and observational dataRetrieval of greenhouse gases from GOSAT and GOSAT-2 using the FOCAL algorithmSynergistic retrieval and Complete Data Fusion methods applied to FORUM and IASI-NG simulated measurementsSynergy of Using Nadir and Limb Instruments for Tropospheric Ozone Monitoring (SUNLIT)TUNER-compliant error estimation for MIPASDARCLOS: a cloud shadow detection algorithm for TROPOMICombined UV and IR ozone profile retrieval from TROPOMI and CrIS measurementsImproved ozone monitoring by ground-based FTIR spectrometryOn the consistency of methane retrievals using the Total Carbon Column Observing Network (TCCON) and multiple spectroscopic databasesThe MOPITT Version 9 CO product: sampling enhancements and validationRetrieving H2O/HDO columns over cloudy and clear-sky scenes from the Tropospheric Monitoring Instrument (TROPOMI)Sentinel-5P TROPOMI NO2 retrieval: impact of version v2.2 improvements and comparisons with OMI and ground-based dataLevel 2 processor and auxiliary data for ESA Version 8 final full mission analysis of MIPAS measurements on ENVISATOptimized Umkehr profile algorithm for ozone trend analysesMapping methane plumes at very high spatial resolution with the WorldView-3 satelliteMapping the spatial distribution of NO2 with in situ and remote sensing instruments during the Munich NO2 imaging campaignImproved monitoring of shipping NO2 with TROPOMI: decreasing NOx emissions in European seas during the COVID-19 pandemicSimulated multispectral temperature and atmospheric composition retrievals for the JPL GEO-IR SounderTruth and uncertainty. A critical discussion of the error concept versus the uncertainty conceptCalculating the vertical column density of O4 during daytime from surface values of pressure, temperature, and relative humidityAutomated detection of atmospheric NO2 plumes from satellite data: a tool to help infer anthropogenic combustion emissionsThe FORUM end-to-end simulator project: architecture and resultsNew sampling strategy mitigates a solar-geometry-induced bias in sub-kilometre vapour scaling statistics derived from imaging spectroscopyRemote sensing of methane plumes: instrument tradeoff analysis for detecting and quantifying local sources at global scaleThe ESA MIPAS/Envisat level2-v8 dataset: 10 years of measurements retrieved with ORM v8.22Phosgene distribution derived from MIPAS ESA v8 data: intercomparisons and trendsGlyoxal tropospheric column retrievals from TROPOMI – multi-satellite intercomparison and ground-based validationRetrieval algorithm for OClO from TROPOMI (TROPOspheric Monitoring Instrument) by differential optical absorption spectroscopyTracking aerosols and SO2 clouds from the Raikoke eruption: 3D view from satellite observationsA minimum curvature algorithm for tomographic reconstruction of atmospheric chemicals based on optical remote sensingAn improved TROPOMI tropospheric NO2 research product over EuropeNeural-network-based estimation of regional-scale anthropogenic CO2 emissions using an Orbiting Carbon Observatory-2 (OCO-2) dataset over East and West AsiaAre elevated moist layers a blind spot for hyperspectral infrared sounders? A model study
Eric Sauvageat, Eliane Maillard Barras, Klemens Hocke, Alexander Haefele, and Axel Murk
Atmos. Meas. Tech., 15, 6395–6417,Short summary
We present new harmonized ozone time series from two ground-based microwave radiometers in Switzerland. The new series consist of hourly ozone profiles in the middle atmosphere (~ 20–70 km) from 2009 until 2021. Cross-validation of the new data series shows the benefit of the harmonization process compared to the previous versions. Comparisons with collocated satellite observations is used to further validate these time series for long-term ozone monitoring over central Europe.
Carlo Arosio, Alexei Rozanov, Victor Gorshelev, Alexandra Laeng, and John P. Burrows
Atmos. Meas. Tech., 15, 5949–5967,Short summary
This paper characterizes the uncertainties affecting the ozone profiles retrieved at the University of Bremen through OMPS limb satellite observations. An accurate knowledge of the uncertainties is relevant for the validation of the product and to correctly interpret the retrieval results. We investigate several sources of uncertainties, estimate a total random and systematic component, and verify the consistency of the combined OMPS-MLS total uncertainty.
Xinzhou Huang and Kai Yang
Atmos. Meas. Tech., 15, 5877–5915,Short summary
This paper describes the algorithm for O3 and SO2 retrievals from DSCOVR EPIC. Algorithm advances, including the improved O3 profile representation and the regulated direct fitting inversion technique, improve the accuracy of O3 and SO2 from the multi-channel measurements of DSCOVR EPIC. A thorough error analysis is provided to quantify O3 and SO2 retrieval uncertainties due to various error sources and simplified algorithm physics treatments.
Huan Yu, Claudia Emde, Arve Kylling, Ben Veihelmann, Bernhard Mayer, Kerstin Stebel, and Michel Van Roozendael
Atmos. Meas. Tech., 15, 5743–5768,Short summary
In this study, we have investigated the impact of 3D clouds on the tropospheric NO2 retrieval from UV–visible sensors. We applied standard NO2 retrieval methods including cloud corrections to synthetic data generated by the 3D radiative transfer model. A sensitivity study was done for synthetic data, and dependencies on various parameters were investigated. Possible mitigation strategies were investigated and compared based on 3D simulations and observed data.
Klaus-Peter Heue, Diego Loyola, Fabian Romahn, Walter Zimmer, Simon Chabrillat, Quentin Errera, Jerry Ziemke, and Natalya Kramarova
Atmos. Meas. Tech., 15, 5563–5579,Short summary
To retrieve tropospheric ozone column information, we subtract stratospheric column data of BASCOE from TROPOMI/S5P total ozone columns. The new S5P-BASCOE data agree well with existing tropospheric data like OMPS-MERRA-2. The data are also compared to ozone soundings. The tropospheric ozone columns show the expected temporal and spatial patterns. We will also apply the algorithm to future UV nadir missions like Sentinel 4 or 5 or to recent and ongoing missions like GOME_2 or OMI.
Can Li, Joanna Joiner, Fei Liu, Nickolay A. Krotkov, Vitali Fioletov, and Chris McLinden
Atmos. Meas. Tech., 15, 5497–5514,Short summary
Satellite observations provide information on the sources of SO2, an important pollutant that affects both air quality and climate. However, these observations suffer from relatively poor data quality due to weak signals of SO2. Here, we use a machine learning technique to analyze satellite SO2 observations in order to reduce the noise and artifacts over relatively clean areas while keeping the signals near pollution sources. This leads to significant improvement in satellite SO2 data.
Elise Potier, Grégoire Broquet, Yilong Wang, Diego Santaren, Antoine Berchet, Isabelle Pison, Julia Marshall, Philippe Ciais, François-Marie Bréon, and Frédéric Chevallier
Atmos. Meas. Tech., 15, 5261–5288,Short summary
Atmospheric inversion at local–regional scales over Europe and pseudo-data assimilation are used to evaluate how CO2 and 14CO2 ground-based measurement networks could complement satellite CO2 imagers to monitor fossil fuel (FF) CO2 emissions. This combination significantly improves precision in the FF emission estimates in areas with a dense network but does not strongly support the separation of the FF from the biogenic signals or the spatio-temporal extrapolation of the satellite information.
François-Marie Bréon, Leslie David, Pierre Chatelanaz, and Frédéric Chevallier
Atmos. Meas. Tech., 15, 5219–5234,Short summary
The estimate of atmospheric CO2 from space measurement is difficult. Current methods are based on a detailed description of the atmospheric radiative transfer. These are affected by significant biases and errors and are very computer intensive. Instead we have proposed using a neural network approach. A first attempt led to confusing results. Here we provide an interpretation for these results and describe a new version that leads to high-quality estimates.
Matthieu Dogniaux, Cyril Crevoisier, Silvère Gousset, Étienne Le Coarer, Yann Ferrec, Laurence Croizé, Lianghai Wu, Otto Hasekamp, Bojan Sic, and Laure Brooker
Atmos. Meas. Tech., 15, 4835–4858,Short summary
The Space Carbon Observatory (SCARBO) concept proposes a constellation of small satellites that would carry a miniaturized Fabry–Pérot imaging interferometer named NanoCarb and an aerosol instrument named SPEXone. In this work, we assess the performance of this concept for the retrieval of the total weighted columns of CO2 and CH4 and show the interest of adding the SPEXone aerosol instrument to improve the CO2 and CH4 column retrieval.
Nicolas Theys, Christophe Lerot, Hugues Brenot, Jeroen van Gent, Isabelle De Smedt, Lieven Clarisse, Mike Burton, Matthew Varnam, Catherine Hayer, Benjamin Esse, and Michel Van Roozendael
Atmos. Meas. Tech., 15, 4801–4817,Short summary
Sulfur dioxide plume height after a volcanic eruption is an important piece of information for many different scientific studies and applications. Satellite UV retrievals are useful in this respect, but available algorithms have shown so far limited sensitivity to SO2 height. Here we present a new technique to improve the retrieval of SO2 plume height for SO2 columns as low as 5 DU. We demonstrate the algorithm using TROPOMI measurements and compare with other height estimates.
Omaira E. García, Esther Sanromá, Frank Hase, Matthias Schneider, Sergio Fabián León-Luis, Thomas Blumenstock, Eliezer Sepúlveda, Carlos Torres, Natalia Prats, Alberto Redondas, and Virgilio Carreño
Atmos. Meas. Tech., 15, 4547–4567,Short summary
Retrieving high-precision concentrations of atmospheric trace gases from FTIR (Fourier transform infrared) spectrometry requires a precise knowledge of the instrumental performance. In this context, this paper examines the impact on the ozone (O3) retrievals of several approaches used to characterise the instrumental line shape (ILS) function of ground-based FTIR spectrometers within NDACC (Network for the Detection of Atmospheric Composition Change).
Xiangyu Zeng, Wei Wang, Cheng Liu, Changgong Shan, Yu Xie, Peng Wu, Qianqian Zhu, and Alexander Polyakov
CFC-11 and CFC-12, which are classified as ozone depleting substances, also have high global warming potentials. This paper describes obtaining the CFC-11 and CFC-12 vertical profiles and total columns from the solar spectra based on ground-based Fourier transform infrared spectroscopy at Hefei, China. The seasonal variation and annual trend of the two gases are analyzed, and then the data are compared with other independent datasets.
Matthias Schneider, Benjamin Ertl, Qiansi Tu, Christopher J. Diekmann, Farahnaz Khosrawi, Amelie N. Röhling, Frank Hase, Darko Dubravica, Omaira E. García, Eliezer Sepúlveda, Tobias Borsdorff, Jochen Landgraf, Alba Lorente, André Butz, Huilin Chen, Rigel Kivi, Thomas Laemmel, Michel Ramonet, Cyril Crevoisier, Jérome Pernin, Martin Steinbacher, Frank Meinhardt, Kimberly Strong, Debra Wunch, Thorsten Warneke, Coleen Roehl, Paul O. Wennberg, Isamu Morino, Laura T. Iraci, Kei Shiomi, Nicholas M. Deutscher, David W. T. Griffith, Voltaire A. Velazco, and David F. Pollard
Atmos. Meas. Tech., 15, 4339–4371,Short summary
We present a computationally very efficient method for the synergetic use of level 2 remote-sensing data products. We apply the method to IASI vertical profile and TROPOMI total column space-borne methane observations and thus gain sensitivity for the tropospheric methane partial columns, which is not achievable by the individual use of TROPOMI and IASI. These synergetic effects are evaluated theoretically and empirically by inter-comparisons to independent references of TCCON, AirCore, and GAW.
Atmos. Meas. Tech., 15, 4407–4410,Short summary
The equivalence between the data fusion performed using the Kalman filter and the Complete Data Fusion has been proved, and a generalization of the Complete Data Fusion formula, that is valid also in the case that the noise error covariance matrices of the fused products are singular, is derived. The two methods are also equivalent to the measurement–space–solution data fusion method, and for moderately nonlinear problems, the three methods are all equivalent to the simultaneous retrieval.
Alba Lorente, Tobias Borsdorff, Mari C. Martinez-Verlarte, Andre Butz, Otto P. Hasekamp, Lianghai Wu, and Jochen Landgraf
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
The TROPOspheric Monitoring Instrument (TROPOMI) performs observations over ocean in every orbit, enhancing the monitoring capabilities of methane from space. In the sun-glint geometry the mirror-like reflection at the water surface provides a signal that is high enough to retrieve methane with high accuracy and precision. We present 4 years of methane concentrations over the ocean, and we assess its quality. We also show the importance of ocean observations to quantify total CH4 emissions.
Kang Sun, Mahdi Yousefi, Christopher Chan Miller, Kelly Chance, Gonzalo González Abad, Iouli E. Gordon, Xiong Liu, Ewan O'Sullivan, Christopher E. Sioris, and Steven C. Wofsy
Atmos. Meas. Tech., 15, 3721–3745,Short summary
This study of upper atmospheric airglow from oxygen is motivated by the need to measure oxygen simultaneously with methane and CO2 in satellite remote sensing. We provide an accurate understanding of the spatial, temporal, and spectral distribution of airglow emissions, which will help in the satellite remote sensing of greenhouse gases and constraining the chemical and physical processes in the upper atmosphere.
Quintus Kleipool, Nico Rozemeijer, Mirna van Hoek, Jonatan Leloux, Erwin Loots, Antje Ludewig, Emiel van der Plas, Daley Adrichem, Raoul Harel, Simon Spronk, Mark ter Linden, Glen Jaross, David Haffner, Pepijn Veefkind, and Pieternel F. Levelt
Atmos. Meas. Tech., 15, 3527–3553,Short summary
A new collection-4 dataset for the Ozone Monitoring Instrument (OMI) mission has been established to supersede the current collection-3 level-1b (L1b) data, produced with a newly developed L01b data processor based on the TROPOspheric Monitoring Instrument (TROPOMI) L01b processor. The collection-4 L1b data have a similar output format to the TROPOMI L1b data for easy connection of the data series. Many insights from the TROPOMI algorithms, as well as from OMI collection-3 usage, were included.
Arve Kylling, Claudia Emde, Huan Yu, Michel van Roozendael, Kerstin Stebel, Ben Veihelmann, and Bernhard Mayer
Atmos. Meas. Tech., 15, 3481–3495,Short summary
Atmospheric trace gases such as nitrogen dioxide (NO2) may be measured by satellite instruments sensitive to solar ultraviolet–visible radiation reflected from Earth and its atmosphere. For a single pixel, clouds in neighbouring pixels may affect the radiation and hence the retrieved trace gas amount. We found that for a solar zenith angle less than about 40° this cloud-related NO2 bias is typically below 10 %, while for larger solar zenith angles the NO2 bias is on the order of tens of percent.
Stefan Noël, Maximilian Reuter, Michael Buchwitz, Jakob Borchardt, Michael Hilker, Oliver Schneising, Heinrich Bovensmann, John P. Burrows, Antonio Di Noia, Robert J. Parker, Hiroshi Suto, Yukio Yoshida, Matthias Buschmann, Nicholas M. Deutscher, Dietrich G. Feist, David W. T. Griffith, Frank Hase, Rigel Kivi, Cheng Liu, Isamu Morino, Justus Notholt, Young-Suk Oh, Hirofumi Ohyama, Christof Petri, David F. Pollard, Markus Rettinger, Coleen Roehl, Constantina Rousogenous, Mahesh Kumar Sha, Kei Shiomi, Kimberly Strong, Ralf Sussmann, Yao Té, Voltaire A. Velazco, Mihalis Vrekoussis, and Thorsten Warneke
Atmos. Meas. Tech., 15, 3401–3437,Short summary
We present a new version (v3) of the GOSAT and GOSAT-2 FOCAL products. In addition to an increased number of XCO2 data, v3 also includes products for XCH4 (full-physics and proxy), XH2O and the relative ratio of HDO to H2O (δD). For GOSAT-2, we also present first XCO and XN2O results. All FOCAL data products show reasonable spatial distribution and temporal variations and agree well with TCCON. Global XN2O maps show a gradient from the tropics to higher latitudes on the order of 15 ppb.
Marco Ridolfi, Cecilia Tirelli, Simone Ceccherini, Claudio Belotti, Ugo Cortesi, and Luca Palchetti
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
Synergistic Retrieval (SR) and Complete Data Fusion (CDF) methods exploit the complementarity of coincident remote sensing measurements. We assess the performance of the SR and CDF methods on the basis of synthetic measurements of the FORUM and IASI-NG missions. In case of perfectly matching measurements, SR and CDF results differ by less than 1/10 of the error due to measurement noise. In case of a realistic mismatch, the two methods show differences of the order of their error bars.
Viktoria F. Sofieva, Risto Hänninen, Mikhail Sofiev, Monika Szeląg, Hei Shing Lee, Johanna Tamminen, and Christian Retscher
Atmos. Meas. Tech., 15, 3193–3212,Short summary
We present tropospheric ozone column datasets that have been created using combinations of total ozone column from OMI and TROPOMI with stratospheric ozone column datasets from several available limb-viewing instruments (MLS, OSIRIS, MIPAS, SCIAMACHY, OMPS-LP, GOMOS). The main results are (i) several methodological developments, (ii) new tropospheric ozone column datasets from OMI and TROPOMI, and (iii) a new high-resolution dataset of ozone profiles from limb satellite instruments.
Thomas von Clarmann, Norbert Glatthor, Udo Grabowski, Bernd Funke, Michael Kiefer, Anne Kleinert, Gabriele P. Stiller, Andrea Linden, and Sylvia Kellmann
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
Errors of profiles of temperature and mixing ratios retrieved from spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding are estimated. All known and quantified sources of uncertainty are considered. Some ingoing uncertaities contribute both to the random and to the systematic error. In some cases, one source of uncertainty propagates onto the error budget via multiple pathways. Problems arise when correlations of errors to be propagated are unknown.
Victor J. H. Trees, Ping Wang, Piet Stammes, Lieuwe G. Tilstra, David P. Donovan, and A. Pier Siebesma
Atmos. Meas. Tech., 15, 3121–3140,Short summary
Cloud shadows are observed by the TROPOMI satellite instrument as a result of its high spatial resolution. These shadows contaminate TROPOMI's air quality measurements, because shadows are generally not taken into account in the models that are used for aerosol and trace gas retrievals. We present the Detection AlgoRithm for CLOud Shadows (DARCLOS) for TROPOMI, which is the first cloud shadow detection algorithm for a satellite spectrometer.
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,Short summary
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.
Omaira Elena García, Esther Sanromá, Matthias Schneider, Frank Hase, Sergio Fabián León-Luis, Thomas Blumenstock, Eliezer Sepúlveda, Alberto Redondas, Virgilio Carreño, Carlos Torres, and Natalia Prats
Atmos. Meas. Tech., 15, 2557–2577,Short summary
Accurate observations of atmospheric ozone (O3) are essential to monitor in detail its key role in atmospheric chemistry. In this context, this paper has assessed the effect of using different retrieval strategies on the quality of O3 products from ground-based NDACC FTIR (Fourier transform infrared) spectrometry, with the aim of providing an improved O3 retrieval that could be applied at any NDACC FTIR station.
Edward Malina, Ben Veihelmann, Matthias Buschmann, Nicholas M. Deutscher, Dietrich G. Feist, and Isamu Morino
Atmos. Meas. Tech., 15, 2377–2406,Short summary
Methane retrievals from remote sensing instruments are fundamentally based on spectroscopic parameters, which indicate spectral-line positions, and their characteristics. These parameters are stored in several databases that vary in their make-up. Here we assess how concentrations of methane isotopologues measured from the same Total Carbon Column Observing Network (TCCON) instruments vary across a range of spectral windows using different spectroscopic databases and comment on the implications.
Merritt Deeter, Gene Francis, John Gille, Debbie Mao, Sara Martínez-Alonso, Helen Worden, Dan Ziskin, James Drummond, Róisín Commane, Glenn Diskin, and Kathryn McKain
Atmos. Meas. Tech., 15, 2325–2344,Short summary
The MOPITT (Measurements of Pollution in the Troposphere) satellite instrument uses remote sensing to obtain retrievals (measurements) of carbon monoxide (CO) in the atmosphere. This paper describes the latest MOPITT data product, Version 9. Globally, the number of daytime MOPITT retrievals over land has increased by 30 %–40 % compared to the previous product. The reported improvements in the MOPITT product should benefit a wide variety of applications including studies of pollution sources.
Andreas Schneider, Tobias Borsdorff, Joost aan de Brugh, Alba Lorente, Franziska Aemisegger, David Noone, Dean Henze, Rigel Kivi, and Jochen Landgraf
Atmos. Meas. Tech., 15, 2251–2275,Short summary
This paper presents an extended H₂O/HDO total column dataset from short-wave infrared measurements by TROPOMI including cloudy and clear-sky scenes. Coverage is tremendously increased compared to previous TROPOMI HDO datasets. The new dataset is validated against recent ground-based FTIR measurements from TCCON and against aircraft measurements over the ocean. The use of the new dataset is demonstrated with a case study of a cold air outbreak in January 2020.
Jos van Geffen, Henk Eskes, Steven Compernolle, Gaia Pinardi, Tijl Verhoelst, Jean-Christopher Lambert, Maarten Sneep, Mark ter Linden, Antje Ludewig, K. Folkert Boersma, and J. Pepijn Veefkind
Atmos. Meas. Tech., 15, 2037–2060,Short summary
Nitrogen dioxide (NO2) is one of the main data products measured by the Tropospheric Monitoring Instrument (TROPOMI) on the Sentinel-5 Precursor (S5P) satellite. This study describes improvements in the TROPOMI NO2 retrieval leading to version v2.2, operational since 1 July 2021. It compares results with previous versions v1.2–v1.4 and with Ozone Monitoring Instrument (OMI) and ground-based measurements.
Piera Raspollini, Enrico Arnone, Flavio Barbara, Massimo Bianchini, Bruno Carli, Simone Ceccherini, Martyn P. Chipperfield, Angelika Dehn, Stefano Della Fera, Bianca Maria Dinelli, Anu Dudhia, Jean-Marie Flaud, Marco Gai, Michael Kiefer, Manuel López-Puertas, David P. Moore, Alessandro Piro, John J. Remedios, Marco Ridolfi, Harjinder Sembhi, Luca Sgheri, and Nicola Zoppetti
Atmos. Meas. Tech., 15, 1871–1901,Short summary
The MIPAS instrument onboard the ENVISAT satellite provided 10 years of measurements of the atmospheric emission al limb that allow for the retrieval of latitude- and altitude-resolved atmospheric composition. We describe the improvements implemented in the retrieval algorithm used for the full mission reanalysis, which allows for the generation of the global distributions of 21 atmospheric constituents plus temperature with increased accuracy with respect to previously generated data.
Irina Petropavlovskikh, Koji Miyagawa, Audra McClure-Beegle, Bryan Johnson, Jeannette Wild, Susan Strahan, Krzysztof Wargan, Richard Querel, Lawrence Flynn, Eric Beach, Gerard Ancellet, and Sophie Godin-Beekmann
Atmos. Meas. Tech., 15, 1849–1870,Short summary
The Montreal Protocol and its amendments assure the recovery of the stratospheric ozone layer that protects the Earth from harmful ultraviolet radiation. To monitor ozone recovery, multiple satellites and ground-based observational platforms collect ozone data. The changes in instruments can influence the continuation of the ozone data. We discuss a method to remove instrumental artifacts from ozone records to improve the internal consistency among multiple observational records.
Elena Sánchez-García, Javier Gorroño, Itziar Irakulis-Loitxate, Daniel J. Varon, and Luis Guanter
Atmos. Meas. Tech., 15, 1657–1674,Short summary
This study seeks to present the as-yet-unknown potential use of WorldView-3 for the mapping of methane point source emissions. The proposed retrieval methodology is based on the idea that the spectral channels not affected by methane can be used to predict the methane-affected band through regression analysis. The results show the precise location of 26 independent point emissions over different methane hotspot regions worldwide, which prove the game-changing potential that this mission entails.
Gerrit Kuhlmann, Ka Lok Chan, Sebastian Donner, Ying Zhu, Marc Schwaerzel, Steffen Dörner, Jia Chen, Andreas Hueni, Duc Hai Nguyen, Alexander Damm, Annette Schütt, Florian Dietrich, Dominik Brunner, Cheng Liu, Brigitte Buchmann, Thomas Wagner, and Mark Wenig
Atmos. Meas. Tech., 15, 1609–1629,Short summary
Nitrogen dioxide (NO2) is an air pollutant whose concentration often exceeds air quality guideline values, especially in urban areas. To map the spatial distribution of NO2 in Munich, we conducted the Munich NO2 Imaging Campaign (MuNIC), where NO2 was measured with stationary, mobile, and airborne in situ and remote sensing instruments. The campaign provides a unique dataset that has been used to compare the different instruments and to study the spatial variability of NO2 and its sources.
Tobias Christoph Valentin Werner Riess, Klaas Folkert Boersma, Jasper van Vliet, Wouter Peters, Maarten Sneep, Henk Eskes, and Jos van Geffen
Atmos. Meas. Tech., 15, 1415–1438,Short summary
This paper reports on improved monitoring of ship nitrogen oxide emissions by TROPOMI. With its fantastic resolution we can identify lanes of ship nitrogen dioxide (NO2) pollution not detected from space before. The quality of TROPOMI NO2 data over sea is improved further by recent upgrades in cloud retrievals and the use of sun glint scenes. Lastly, we study the impact of COVID-19 on ship NO2 in European seas and compare the found reductions to emission estimates gained from ship-specific data.
Vijay Natraj, Ming Luo, Jean-Francois Blavier, Vivienne H. Payne, Derek J. Posselt, Stanley P. Sander, Zhao-Cheng Zeng, Jessica L. Neu, Denis Tremblay, Longtao Wu, Jacola A. Roman, Yen-Hung Wu, and Leonard I. Dorsky
Atmos. Meas. Tech., 15, 1251–1267,Short summary
High-fidelity monitoring and forecast of air quality and the hydrological cycle require understanding the vertical distribution of temperature, humidity, and trace gases at high spatiotemporal resolution. We describe a new instrument concept, called the JPL GEO-IR Sounder, that would provide this information for the first time from a single instrument platform. Simulations demonstrate the benefits of combining measurements from multiple wavelengths for this purpose from geostationary orbit.
Thomas von Clarmann, Steven Compernolle, and Frank Hase
Atmos. Meas. Tech., 15, 1145–1157,Short summary
Contrary to the claims put forward in
Evaluation of measurement data – Guide to the expression of uncertainty in measurementissued by the JCGM, the error concept and the uncertainty concept are the same. Arguments in favor of the contrary were found not to be compelling. Neither was any evidence presented that
uncertaintiesdefine a different relation between the measured and true values, nor is a Bayesian concept beyond the mere subjective probability referred to.
Steffen Beirle, Christian Borger, Steffen Dörner, Vinod Kumar, and Thomas Wagner
Atmos. Meas. Tech., 15, 987–1006,Short summary
We present a formalism that relates the vertical column density (VCD) of the oxygen collision complex O4 to surface values of temperature and pressure, based on physical laws. In addition, we propose an empirical modification which also accounts for surface relative humidity (RH). This allows for simple and quick but still accurate calculation of the O4 VCD without the need for constructing full vertical profiles, which is expected to be useful in particular for MAX-DOAS applications.
Douglas P. Finch, Paul I. Palmer, and Tianran Zhang
Atmos. Meas. Tech., 15, 721–733,Short summary
We developed a machine learning model to detect plumes of nitrogen dioxide satellite observations over 2 years. We find over 310 000 plumes, mainly over cities, industrial regions, and areas of oil and gas production. Our model performs well in comparison to other datasets and in some cases finds emissions that are not included in other datasets. This method could be used to help locate and measure emission hotspots across the globe and help inform climate policies.
Luca Sgheri, Claudio Belotti, Maya Ben-Yami, Giovanni Bianchini, Bernardo Carnicero Dominguez, Ugo Cortesi, William Cossich, Samuele Del Bianco, Gianluca Di Natale, Tomás Guardabrazo, Dulce Lajas, Tiziano Maestri, Davide Magurno, Hilke Oetjen, Piera Raspollini, and Cristina Sgattoni
Atmos. Meas. Tech., 15, 573–604,Short summary
The FORUM instrument will look at the Earth's atmosphere from a satellite, covering a spectral range responsible for about 95 % of the radiation lost by our planet. FORUM helps to measure the imbalance between incoming and outgoing radiation that is responsible for the increasing average temperatures on Earth. The end-to-end simulator is a chain of codes that simulates the FORUM measurement process. The goal of the project is to study how the instrument reacts to different retrieval conditions.
Mark T. Richardson, David R. Thompson, Marcin J. Kurowski, and Matthew D. Lebsock
Atmos. Meas. Tech., 15, 117–129,Short summary
Sunlight can pass diagonally through the atmosphere, cutting through the 3-D water vapour field in a way that
smears2-D maps of imaging spectroscopy vapour retrievals. In simulations we show how this smearing is
away fromthe Sun, so calculating
across the solar direction allows sub-kilometre information about water vapour's spatial scaling to be calculated. This could be tested by airborne campaigns and used to obtain new information from upcoming spaceborne data products.
Siraput Jongaramrungruang, Georgios Matheou, Andrew K. Thorpe, Zhao-Cheng Zeng, and Christian Frankenberg
Atmos. Meas. Tech., 14, 7999–8017,Short summary
This study shows how precision error and bias in column methane retrieval change with different instrument specifications and the impact of spectrally complex surface albedos on retrievals. We show how surface interferences can be mitigated with an optimal spectral resolution and a higher polynomial degree in a retrieval process. The findings can inform future satellite instrument designs to have robust observations capable of separating real CH4 plume enhancements from surface interferences.
Bianca Maria Dinelli, Piera Raspollini, Marco Gai, Luca Sgheri, Marco Ridolfi, Simone Ceccherini, Flavio Barbara, Nicola Zoppetti, Elisa Castelli, Enzo Papandrea, Paolo Pettinari, Angelika Dehn, Anu Dudhia, Michael Kiefer, Alessandro Piro, Jean-Marie Flaud, Manuel López-Puertas, David Moore, John Remedios, and Massimo Bianchini
Atmos. Meas. Tech., 14, 7975–7998,Short summary
The level-2 v8 database from the measurements of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), aboard the European Space Agency Envisat satellite, containing atmospheric fields of pressure, temperature, and volume mixing ratio of 21 trace gases, is described in this paper. The database covers all the measurements acquired by MIPAS (from July 2002 to April 2012). The number of species included makes it of particular importance for the studies of stratospheric chemistry.
Paolo Pettinari, Flavio Barbara, Simone Ceccherini, Bianca Maria Dinelli, Marco Gai, Piera Raspollini, Luca Sgheri, Massimo Valeri, Gerald Wetzel, Nicola Zoppetti, and Marco Ridolfi
Atmos. Meas. Tech., 14, 7959–7974,Short summary
Phosgene (COCl2) is a toxic gas whose presence is a consequence of human activity. Besides its direct injection in the troposphere, stratospheric COCl2 is produced from the decomposition of CCl4, an anthropogenic gas regulated by the Montreal Protocol. As a consequence, COCl2 negative trends characterize the lower and part of the middle stratosphere. However, we find positive trends in the upper troposphere, demonstrating the non-negligible role of other Cl-containing species not yet regulated.
Christophe Lerot, François Hendrick, Michel Van Roozendael, Leonardo M. A. Alvarado, Andreas Richter, Isabelle De Smedt, Nicolas Theys, Jonas Vlietinck, Huan Yu, Jeroen Van Gent, Trissevgeni Stavrakou, Jean-François Müller, Pieter Valks, Diego Loyola, Hitoshi Irie, Vinod Kumar, Thomas Wagner, Stefan F. Schreier, Vinayak Sinha, Ting Wang, Pucai Wang, and Christian Retscher
Atmos. Meas. Tech., 14, 7775–7807,Short summary
Global measurements of glyoxal tropospheric columns from the satellite instrument TROPOMI are presented. Such measurements can contribute to the estimation of atmospheric emissions of volatile organic compounds. This new glyoxal product has been fully characterized with a comprehensive error budget, with comparison with other satellite data sets as well as with validation based on independent ground-based remote sensing glyoxal observations.
Jānis Puķīte, Christian Borger, Steffen Dörner, Myojeong Gu, Udo Frieß, Andreas Carlos Meier, Carl-Fredrik Enell, Uwe Raffalski, Andreas Richter, and Thomas Wagner
Atmos. Meas. Tech., 14, 7595–7625,Short summary
Chlorine dioxide (OClO) is used as an indicator for chlorine activation. We present a new differential optical absorption spectroscopy retrieval algorithm for OClO from measurements of TROPOMI on the Sentinel-5P satellite. To achieve a substantially improved accuracy for the weak absorber OClO, we consider several additional fit parameters accounting for various higher-order spectral effects. The retrieved OClO slant column densities are compared with ground-based zenith sky measurements.
Nick Gorkavyi, Nickolay Krotkov, Can Li, Leslie Lait, Peter Colarco, Simon Carn, Matthew DeLand, Paul Newman, Mark Schoeberl, Ghassan Taha, Omar Torres, Alexander Vasilkov, and Joanna Joiner
Atmos. Meas. Tech., 14, 7545–7563,Short summary
The 21 June 2019 eruption of the Raikoke volcano produced significant amounts of volcanic aerosols (sulfate and ash) and sulfur dioxide (SO2) gas that penetrated into the lower stratosphere. We showed that the amount of SO2 decreases with a characteristic period of 8–18 d and the peak of sulfate aerosol lags the initial peak of SO2 by 1.5 months. We also examined the dynamics of an unusual stratospheric coherent circular cloud of SO2 and aerosol observed from 18 July to 22 September 2019.
Sheng Li and Ke Du
Atmos. Meas. Tech., 14, 7355–7368,Short summary
A new minimum curvature algorithm has been proposed for tomographic mapping of air chemicals using optical remote sensing based on the seminorms in variational interpolation. The algorithm was evaluated by using multiple test maps. It shows significant improvement compared with the nonsmoothed algorithm, requires only approximately 65 % computation time of the low third derivative algorithm, and is simple to implement by directly using high-resolution grids.
Song Liu, Pieter Valks, Gaia Pinardi, Jian Xu, Ka Lok Chan, Athina Argyrouli, Ronny Lutz, Steffen Beirle, Ehsan Khorsandi, Frank Baier, Vincent Huijnen, Alkiviadis Bais, Sebastian Donner, Steffen Dörner, Myrto Gratsea, François Hendrick, Dimitris Karagkiozidis, Kezia Lange, Ankie J. M. Piters, Julia Remmers, Andreas Richter, Michel Van Roozendael, Thomas Wagner, Mark Wenig, and Diego G. Loyola
Atmos. Meas. Tech., 14, 7297–7327,Short summary
In this work, an improved tropospheric NO2 retrieval algorithm from TROPOMI measurements over Europe is presented. The stratospheric estimation is implemented with correction for the dependency of the stratospheric NO2 on the viewing geometry. The AMF calculation is implemented using improved surface albedo, a priori NO2 profiles, and cloud correction. The improved tropospheric NO2 data show good correlations with ground-based MAX-DOAS measurements.
Farhan Mustafa, Lingbing Bu, Qin Wang, Na Yao, Muhammad Shahzaman, Muhammad Bilal, Rana Waqar Aslam, and Rashid Iqbal
Atmos. Meas. Tech., 14, 7277–7290,Short summary
A neural-network-based approach was suggested to estimate CO2 emissions using satellite-based net primary productivity (NPP) and XCO2 retrievals. XCO2 anomalies were calculated for each year using OCO-2 retrievals. A Generalized Regression Neural Network (GRNN) model was then built; NPP, XCO2 anomalies, and ODIAC CO2 emissions from 2015 to 2018 were used as a training dataset; and, finally, CO2 emissions were predicted for 2019 based on the NPP and XCO2 anomalies calculated for the same year.
Marc Prange, Manfred Brath, and Stefan A. Buehler
Atmos. Meas. Tech., 14, 7025–7044,Short summary
We investigate the ability of the hyperspectral infrared satellite instrument IASI to resolve moist layers in the tropical free troposphere in a model framework. Previous observational results indicated major deficiencies of passive satellite instruments in resolving moist layers around the freezing level. We conduct a first systematic hyperspectral infrared retrieval analysis of such moist layers and conclude that no inherent satellite blind spot for moist layers exists.
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While measuring sulfur dioxide fluxes in volcanic plumes with a UV-sensitive camera, the wind direction can influence the retrieved fluxes. If the volcanic plume is tilted in the field of view of the camera, it can lead to over- or underestimations of the determined fluxes. This paper presents a method to deal with such a circumstance. Additionally, it provides the possibility to determine the wind direction of the plume directly from the image time series themselves.
While measuring sulfur dioxide fluxes in volcanic plumes with a UV-sensitive camera, the wind...