Articles | Volume 8, issue 6
Atmos. Meas. Tech., 8, 2531–2542, 2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article 23 Jun 2015
Research article | 23 Jun 2015
Systematic evaluation of the impacts of GPSRO data on the prediction of typhoons over the northwestern Pacific in 2008–2010
Y.-C. Chen et al.
No articles found.
Z. Zeng, S. Sokolovskiy, W. Schreiner, D. Hunt, J. Lin, and Y.-H. Kuo
Atmos. Meas. Tech., 9, 335–346,Short summary
This study discusses the ionospheric correction problem of RO data in the troposphere and investigates an optimal transition height (OTH) for replacing the standard linear combination method by the L1–L2 bending angle extrapolated from above. By comparing the RO ionosphere-free bending angles with the ECMWF global forecast ones, the OTH is found when it gives the minimal standard deviations. The results show the OTH depends mainly on the L2 signal and is ~20 km for COSMIC L2P and ~10 km for L2C.
T.-K. Wee and Y.-H. Kuo
Atmos. Meas. Tech., 8, 4281–4294,
X. Yue, W. S. Schreiner, Z. Zeng, Y.-H. Kuo, and X. Xue
Atmos. Meas. Tech., 8, 225–236,Short summary
The occurrence of sporadic E (Es) layers has been a hot scientific topic for a long time. GNSS (global navigation satellite system)-based radio occultation (RO) has proven to be a powerful technique for detecting the global Es layers. In this paper, we show some examples of multiple Es layers occurring in one RO event and the occurrence of Es in a broad region during a certain time interval. The results are then evaluated by independent observations such as lidar and ionosondes.
A. K. Steiner, D. Hunt, S.-P. Ho, G. Kirchengast, A. J. Mannucci, B. Scherllin-Pirscher, H. Gleisner, A. von Engeln, T. Schmidt, C. Ao, S. S. Leroy, E. R. Kursinski, U. Foelsche, M. Gorbunov, S. Heise, Y.-H. Kuo, K. B. Lauritsen, C. Marquardt, C. Rocken, W. Schreiner, S. Sokolovskiy, S. Syndergaard, and J. Wickert
Atmos. Chem. Phys., 13, 1469–1484,
Related subject area
Subject: Others (Wind, Precipitation, Temperature, etc.) | Technique: Remote Sensing | Topic: Validation and IntercomparisonsValidation of the TROPOspheric Monitoring Instrument (TROPOMI) surface UV radiation productImprovement of numerical weather prediction model analysis during fog conditions through the assimilation of ground-based microwave radiometer observations: a 1D-Var studyValidation of Aeolus wind products above the Atlantic OceanCommercial microwave links as a tool for operational rainfall monitoring in Northern ItalyInter-calibration of nine UV sensing instruments over Antarctica and Greenland since 1980Inter-calibrating SMMR brightness temperatures over continental surfacesValidating HY-2A CMR precipitable water vapor using ground-based and shipborne GNSS observationsValidation of temperature data from the RAman Lidar for Meteorological Observations (RALMO) at Payerne. An application to liquid cloud supersaturationRetrieval of lower-order moments of the drop size distribution using CSU-CHILL X-band polarimetric radar: a case studyA two-year intercomparison of CW focusing wind lidar and tall mast wind measurements at CabauwGradient boosting machine learning to improve satellite-derived column water vapor measurement errorFlywheel calibration of a continuous-wave coherent Doppler wind lidarEvaluation of the 15-year ROM SAF monthly mean GPS radio occultation climate data recordConsistency and structural uncertainty of multi-mission GPS radio occultation recordsFirst validation of Aeolus wind observations by airborne Doppler wind lidar measurementsIntercomparison of wind observations from the European Space Agency's Aeolus satellite mission and the ALADIN Airborne DemonstratorUncertainty Quantification for Atmospheric Motion Vectors with Machine LearningCalibration and validation of the Polarimetric Radio Occultation and Heavy Precipitation experiment aboard the PAZ satelliteAutomatic quality control of the Meteosat First Generation measurementsConcurrent satellite and ground-based lightning observations from the Optical Lightning Imaging Sensor (ISS-LIS), the low-frequency network Meteorage and the SAETTA Lightning Mapping Array (LMA) in the northwestern Mediterranean regionUsing ground radar overlaps to verify the retrieval of calibration bias estimates from spaceborne platformsA geometry-dependent surface Lambertian-equivalent reflectivity product for UV–Vis retrievals – Part 2: Evaluation over open oceanOn the zero-level offset in the GOSAT TANSO-FTS O2 A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2Evaluation of GPM-DPR precipitation estimates with WegenerNet gauge dataA study of a two-dimensional scanned lunar image for Advanced Technology Microwave Sounder (ATMS) geometric calibrationMultistatic meteor radar observations of gravity-wave–tidal interaction over southern AustraliaA geometry-dependent surface Lambertian-equivalent reflectivity product for UV–Vis retrievals – Part 1: Evaluation over land surfaces using measurements from OMI at 466 nmRetrieval of convective available potential energy from INSAT-3D measurements: comparison with radiosonde data and their spatial–temporal variationsLidar temperature series in the middle atmosphere as a reference data set – Part 2: Assessment of temperature observations from MLS/Aura and SABER/TIMED satellitesPotential of INSAT-3D sounder-derived total precipitable water product for weather forecastLidar temperature series in the middle atmosphere as a reference data set – Part 1: Improved retrievals and a 20-year cross-validation of two co-located French lidarsEnhancing the consistency of spaceborne and ground-based radar comparisons by using beam blockage fraction as a quality filterRainfall retrieval with commercial microwave links in São Paulo, BrazilEvaluating two methods of estimating error variances using simulated data sets with known errorsEstimation of turbulence dissipation rate and its variability from sonic anemometer and wind Doppler lidar during the XPIA field campaignInter-channel uniformity of a microwave sounder in spaceFrom model to radar variables: a new forward polarimetric radar operator for COSMOEvaluating tropospheric humidity from GPS radio occultation, radiosonde, and AIRS from high-resolution time seriesReducing representativeness and sampling errors in radio occultation–radiosonde comparisonsEvaluating the lower-tropospheric COSMIC GPS radio occultation sounding quality over the ArcticValidation of new satellite rainfall products over the Upper Blue Nile Basin, EthiopiaIntercomparison of middle-atmospheric wind in observations and modelsUncertainty characterization of HOAPS 3.3 latent heat-flux-related parametersComparisons of the tropospheric specific humidity from GPS radio occultations with ERA-Interim, NASA MERRA, and AIRS dataAn intercomparison of stratospheric gravity wave potential energy densities from METOP GPS radio occultation measurements and ECMWF model dataAssessment of surface solar irradiance derived from real-time modelling techniques and verification with ground-based measurementsSensitivity of airborne radio occultation to tropospheric properties over ocean and landIntercomparison of AIRS and HIRDLS stratospheric gravity wave observationsThe importance of atmospheric correction for airborne hyperspectral remote sensing of shallow waters: application to depth estimationCombining ground-based microwave radiometer and the AROME convective scale model through 1DVAR retrievals in complex terrain: an Alpine valley case study
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,Short summary
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.
Pauline Martinet, Domenico Cimini, Frédéric Burnet, Benjamin Ménétrier, Yann Michel, and Vinciane Unger
Atmos. Meas. Tech., 13, 6593–6611,Short summary
Each year large human and economical losses are due to fog episodes. However, fog forecasts remain quite inaccurate, partly due to a lack of observations in the atmospheric boundary layer. The benefit of ground-based microwave radiometers has been investigated and has demonstrated their capability of significantly improving the initial state of temperature and liquid water content profiles in current numerical weather prediction models, paving the way for improved fog forecasts in the future.
Holger Baars, Alina Herzog, Birgit Heese, Kevin Ohneiser, Karsten Hanbuch, Julian Hofer, Zhenping Yin, Ronny Engelmann, and Ulla Wandinger
Atmos. Meas. Tech., 13, 6007–6024,Short summary
A first validation for the European satellite Aeolus is presented. Aeolus is the first satellite that can actively measure horizontal wind profiles from space. Radiosonde launches on board the German research vessel Polarstern have been utilized to validate Aeolus observations over the Atlantic Ocean, a region where almost no other reference measurements are available. It is shown that Aeolus is able to measure accurately atmospheric winds and thus may significantly improve weather forecasts.
Giacomo Roversi, Pier Paolo Alberoni, Anna Fornasiero, and Federico Porcù
Atmos. Meas. Tech., 13, 5779–5797,Short summary
The microwave signal travelling between two antennas of the commercial mobile backhaul network is strongly attenuated by rainfall. The open-source RAINLINK algorithm extracts rainfall rate maps, processing the attenuation data recorded by the transmission system. In this work, we applied RAINLINK to 357 Vodafone links in northern Italy and compared the outputs with the operational rain products of the local weather service (Arpae), outlining pros and cons and discussing error structure.
Clark J. Weaver, Pawan K. Bhartia, Dong L. Wu, Gordon J. Labow, and David E. Haffner
Atmos. Meas. Tech., 13, 5715–5723,Short summary
Currently, we do not know whether clouds will accelerate or moderate climate. We look to the past and ask whether cloudiness has changed over the last 4 decades. Using a suite of nine satellite instruments, we need to ensure that the first satellite, which was launched in 1980 and died in 1991, observed the same measurement as the eight other satellite instruments used in the record. If the instruments were measuring length and observing a 1.00 m long stick, they would all see 0.99 to 1.01 m.
Samuel Favrichon, Carlos Jimenez, and Catherine Prigent
Atmos. Meas. Tech., 13, 5481–5490,Short summary
Long-term monitoring of satellite-derived variables is necessary for a better understanding of the evolution of Earth parameters at global scale. However different instruments' observations used over the years need to be inter-calibrated with each other to provide meaningful information. This paper describes how a linear correction can improve the observations from the Scanning Multichannel Microwave Radiometer over continental surfaces to be more consistent with more recent radiometers.
Zhilu Wu, Yanxiong Liu, Yang Liu, Jungang Wang, Xiufeng He, Wenxue Xu, Maorong Ge, and Harald Schuh
Atmos. Meas. Tech., 13, 4963–4972,Short summary
The HY-2A calibration microwave radiometer (CMR) water vapor product is validated using ground-based GNSS observations along the coastline and shipborne GNSS observations over the Indian Ocean. The validation result shows that HY-2A CMR PWV agrees well with ground-based GNSS PWV, with 2.67 mm in rms within 100 km and an RMS of 1.57 mm with shipborne GNSS for the distance threshold of 100 km. Ground-based GNSS and shipborne GNSS agree with HY-2A CMR well.
Giovanni Martucci, Francisco Navas-Guzman, Ludovic Renaud, Gonzague Romanens, S. Mahagammulla Gamage, Maxime Hervo, Pierre Jeannet, and Alexander Haefele
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
This research article presents a validation of 1.5 years of pure rotational temperature data measured by the Raman LIDAR RALMO installed at the MeteoSwiss station of Payerne. The statistical results are in terms of bias and standard deviation with respect to two well-established radiosounding systems. The statistics are divided into daytime (bias = 0.28 K, std = 0.62 ± 0.03 K) and nighttime (bias = 0.29 K, std = 0.66 ± 0.06 K). The Lidar temperature profiles are applied to cloud supersaturation studies.
Viswanathan Bringi, Kumar Vijay Mishra, Merhala Thurai, Patrick C. Kennedy, and Timothy H. Raupach
Atmos. Meas. Tech., 13, 4727–4750,Short summary
The raindrop size distribution and its moments are fundamental in many areas, such as radar measurement of rainfall using polarimetry and numerical modeling of the microphysical processes of rain formation and evolution. We develop a technique which uses advanced radar measurements and complete drop size distributions using two collocated instruments to retrieve the lower-order moments such as total drop concentration and rain water content. We demonstrate a proof-of-concept using a case study.
Steven Knoop, Fred C. Bosveld, Marijn J. de Haij, and Arnoud Apituley
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
Doppler wind lidars are laser-based remote sensing instruments that measure the wind up to a few hundred meters or even a few kilometers. Their data can improve weather models and help forecasters. To investigate their accuracy and required meteorological conditions we have carried out a two-year measurement campaign of a wind lidar at our Cabauw test site and made a comparison with cup anemometers and wind vanes at several levels in a 213-m tall meteorological mast.
Allan C. Just, Yang Liu, Meytar Sorek-Hamer, Johnathan Rush, Michael Dorman, Robert Chatfield, Yujie Wang, Alexei Lyapustin, and Itai Kloog
Atmos. Meas. Tech., 13, 4669–4681,Short summary
A flexible machine-learning model was fit to explain the differences between estimates of water vapor from satellites versus ground stations in Northeastern USA. We use nine variables derived from the satellite acquisition and ground characteristics to explain this measurement error. Our results showed overall good agreement, but data from the Terra satellite were drifting too high in recent summers. Our model reduces measurement error and works well in new locations in the northeast.
Anders Tegtmeier Pedersen and Pedersen Courtney
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
This manuscript suggests and describes a method for calibrating wind lidars using a rotating flywheel. An uncertainty analysis shows that a standard uncertainty of 0.1 % can be achieved with the main contributor being the width of the laser beam which is in agreement with experimental results. The method can potentially lower the calibration uncertainty of wind lidars which today is often based on cup anemometers and thus lead to better wind assesments and perhaps more widespread use.
Hans Gleisner, Kent B. Lauritsen, Johannes K. Nielsen, and Stig Syndergaard
Atmos. Meas. Tech., 13, 3081–3098,Short summary
Data from GPS radio occultation (RO) instruments aboard a series of satellites have been reprocessed by the ROM SAF. We describe the monthly mean RO climate data records (CDRs) and the methods for removing sampling errors. The quality of the CDRs is evaluated, with a focus on systematic differences between satellite missions. Between 8 and 30 km, the data quality and the inter-mission differences are small enough to allow the generation of combined multi-mission data records starting in 2001.
Andrea K. Steiner, Florian Ladstädter, Chi O. Ao, Hans Gleisner, Shu-Peng Ho, Doug Hunt, Torsten Schmidt, Ulrich Foelsche, Gottfried Kirchengast, Ying-Hwa Kuo, Kent B. Lauritsen, Anthony J. Mannucci, Johannes K. Nielsen, William Schreiner, Marc Schwärz, Sergey Sokolovskiy, Stig Syndergaard, and Jens Wickert
Atmos. Meas. Tech., 13, 2547–2575,Short summary
High-quality observations are critically important for monitoring the Earth’s changing climate. We provide information on the consistency and long-term stability of observations from GPS radio occultation (RO). We assess, for the first time, RO records from multiple RO missions and all major RO data providers. Our results quantify where RO can be used for reliable trend assessment and confirm its climate quality.
Benjamin Witschas, Christian Lemmerz, Alexander Geiß, Oliver Lux, Uwe Marksteiner, Stephan Rahm, Oliver Reitebuch, and Fabian Weiler
Atmos. Meas. Tech., 13, 2381–2396,Short summary
Aeolus, the first ever wind lidar in space, has been providing wind profiles on a global scale since its launch. In order to validate the quality of Aeolus wind observations, the German Aerospace Center (DLR) recently performed two airborne campaigns over central Europe deploying two different Doppler wind lidars. A total of 10 satellite underflights were performed and used to validate the early-stage wind data product of Aeolus by means of collocated airborne wind lidar observations.
Oliver Lux, Christian Lemmerz, Fabian Weiler, Uwe Marksteiner, Benjamin Witschas, Stephan Rahm, Alexander Geiß, and Oliver Reitebuch
Atmos. Meas. Tech., 13, 2075–2097,Short summary
This work reports on the first airborne validation campaign of ESA’s Earth Explorer mission Aeolus, conducted in central Europe during the commissioning phase in November 2018. After presenting the methodology used to compare the data sets from the satellite, the airborne wind lidar and the ECWMF model, the wind results from the underflights performed are analyzed and discussed, providing a first assessment of the accuracy and precision of the preliminary Aeolus wind data.
Joaquim V. Teixeira, Hai Nguyen, Derek J. Posselt, Hui Su, and Longtao Wu
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
Wind-tracking algorithms produce atmospheric motion vectors (AMVs) by tracking satellite observations. Accurately characterizing the uncertainties in AMVs is essential in assimilating them into data assimilation models. We develop a machine learning based approach for error characterization which involves gaussian mixture model clustering and random forest using a simulation dataset of water vapor, AMVs, and true winds. We show that our method improves on existing AMV error characterizations.
Ramon Padullés, Chi O. Ao, F. Joseph Turk, Manuel de la Torre Juárez, Byron Iijima, Kuo Nung Wang, and Estel Cardellach
Atmos. Meas. Tech., 13, 1299–1313,Short summary
In this study we thoroughly address the calibration and validation of the new polarimetric radio occultation (PRO) observables. These represent an innovative way to obtain vertical profiles of precipitation along with thermodynamic observations of the same scene. First we perform the on-orbit calibration of the measurement. Then, we show how the PRO observables are sensitive to the presence and intensity of rain by looking for coincident precipitation measurements from independent missions.
Freek Liefhebber, Sarah Lammens, Paul W. G. Brussee, André Bos, Viju O. John, Frank Rüthrich, Jacobus Onderwaater, Michael G. Grant, and Jörg Schulz
Atmos. Meas. Tech., 13, 1167–1179,Short summary
The paper addresses the need for automatic quality control of a whole series of Earth observation (EO) time series extending a period of over 40 years. Such a dataset is valuable and may provide important information about trends related to geo-physical processes. Furthermore, as the dataset is that large, there is a need to completely automate the processes, as otherwise the effort would become impracticable. The result is a system with a high probability of detection and low false alarm rate.
Felix Erdmann, Eric Defer, Olivier Caumont, Richard J. Blakeslee, Stéphane Pédeboy, and Sylvain Coquillat
Atmos. Meas. Tech., 13, 853–875,Short summary
This article compares lightning observations from an optical sensor onboard the International Space Station to two ground-based networks using different radio frequencies. The location and timing of coincident flashes agree well for the three instruments. Differences exist for the detected number of flashes and the characteristics. Small flashes in particular are not always detected by all three instruments. About half of the flashes at altitudes below 10 km are not seen by the satellite sensor.
Irene Crisologo and Maik Heistermann
Atmos. Meas. Tech., 13, 645–659,Short summary
Archives of radar observations often suffer from errors, one of which is calibration. However, it is possible to correct them after the fact by using satellite radars as a calibration reference. We propose improvements to this calibration method by considering factors that affect the data quality, such that poor quality data gets filtered out in the bias calculation by assigning weights. We also show that the bias can be interpolated in time even for days when there are no satellite data.
Zachary Fasnacht, Alexander Vasilkov, David Haffner, Wenhan Qin, Joanna Joiner, Nickolay Krotkov, Andrew M. Sayer, and Robert Spurr
Atmos. Meas. Tech., 12, 6749–6769,Short summary
The anisotropy of Earth's surface reflection plays an important role in satellite-based retrievals of cloud, aerosol, and trace gases. Most current ultraviolet and visible satellite retrievals utilize climatological surface reflectivity databases that do not account for surface anisotropy. The GLER concept was introduced to account for such features. Here we evaluate GLER for water surfaces by comparing with OMI measurements and show that it captures these surface anisotropy features.
Haruki Oshio, Yukio Yoshida, and Tsuneo Matsunaga
Atmos. Meas. Tech., 12, 6721–6735,Short summary
We investigate the radiance offset in the O2 A band of GOSAT spectrometer and quality of the offset-corrected solar-induced chlorophyll fluorescence (SIF). An analysis of temporal variation of the offset suggests that the radiometric sensitivity of the spectrometer changed after switching the optics path selector in January 2015. Comparisons at multiple spatial scales show good agreement between GOSAT SIF and OCO-2 SIF, which supports the consistency among the present satellite SIF data.
Martin Lasser, Sungmin O, and Ulrich Foelsche
Atmos. Meas. Tech., 12, 5055–5070,Short summary
This paper evaluates the rain rate estimates from the Global Precipitation Measurement (GPM) mission's radar instrument by comparing them to the data of the WegenerNet, a local-scale high-resolution network of meteorological stations. Our results show that the GPM-DPR estimates basically match with the WegenerNet measurements, but absolute quantities are biased.
Jun Zhou and Hu Yang
Atmos. Meas. Tech., 12, 4983–4992,Short summary
Evaluating the on-orbit geolocation accuracy of the ATMS is of great importance. The widely used Earth-target-dependent methods are crippled by the strong atmospheric absorption at sounding channels and cloud contamination at window channels. To solve these issues, this study developed a geolocation evaluation algorithm based on a unique 2-D lunar scan dataset captured by the ATMS during a NOAA-20 pitch-over maneuver operation. The results are validated by the coastline inflection point method.
Andrew John Spargo, Iain Murray Reid, and Andrew David MacKinnon
Atmos. Meas. Tech., 12, 4791–4812,Short summary
We simulate the ability of a recently installed multistation meteor detection radar to measure characteristics of turbulence in the Earth's lower ionosphere. After verifying that it performs reasonably well, we use the radar's data to study an interaction between turbulence and tidal effects. We performed the study because no one has yet applied a multistation radar to this problem before and because multistation radars like this are becoming increasingly common worldwide.
Wenhan Qin, Zachary Fasnacht, David Haffner, Alexander Vasilkov, Joanna Joiner, Nickolay Krotkov, Bradford Fisher, and Robert Spurr
Atmos. Meas. Tech., 12, 3997–4017,Short summary
Satellite observations depend on Sun and view angles due to anisotropy of the Earth's atmosphere and surface reflection. But most of the ultraviolet and visible cloud, aerosol, and trace-gas algorithms utilize surface reflectivity databases that do not account for surface anisotropy. We create a surface database using the GLER concept which adequately accounts for surface anisotropy, validate it with independent satellite data, and provide a simple implementation to the current algorithms.
Uriya Veerendra Murali Krishna, Subrata Kumar Das, Kizhathur Narasimhan Uma, and Govindan Pandithurai
Atmos. Meas. Tech., 12, 777–790,Short summary
Convective available potential energy (CAPE) is an indicator of the occurrence of extreme weather. For the first time over India, this study estimated CAPE from high spatial–temporal resolution measurements of the geostationary satellite, INSAT-3D. INSAT-3D estimates that CAPE reasonably represents the radiosonde CAPE. This study allows the atmospheric science community to select the best available dataset for their use in nowcasting and making severe weather warnings based on numerical models.
Robin Wing, Alain Hauchecorne, Philippe Keckhut, Sophie Godin-Beekmann, Sergey Khaykin, and Emily M. McCullough
Atmos. Meas. Tech., 11, 6703–6717,Short summary
We have compared 2433 nights of OHP lidar temperatures (2002–2018) to temperatures derived from the satellites SABER and MLS. We have found a winter stratopause cold bias in the satellite measurements with respect to the lidar (−6 K for SABER and −17 K for MLS), a summer mesospheric warm bias for SABER (6 K near 60 km), and a vertically structured bias for MLS (−4 to 4 K). We have corrected the satellite data based on the lidar-determined stratopause height and found a significant improvement.
Shailesh Parihar, Ashim Kumar Mitra, Mrutyunjay Mohapatra, and Rajjev Bhatla
Atmos. Meas. Tech., 11, 6003–6012,Short summary
This paper is based on operational work carried out at IMD, New Delhi using the INSAT-3D satellite-derived sounder product TPW for weather events such as rainfall and thunderstorms. The INSAT-3D TPW has been used by forecasters as well as many other users over the last 2 years. This work mainly brings out an in-depth validation with in situ ground measurement data as well as a GNSS system for its suitability in weather prediction. This paper can be utilized operationally for weather purposes.
Robin Wing, Alain Hauchecorne, Philippe Keckhut, Sophie Godin-Beekmann, Sergey Khaykin, Emily M. McCullough, Jean-François Mariscal, and Éric d'Almeida
Atmos. Meas. Tech., 11, 5531–5547,Short summary
The objective of this work is to minimize the errors at the highest altitudes of a lidar temperature profile which arise due to background estimation and a priori choice. The systematic method in this paper has the effect of cooling the temperatures at the top of a lidar profile by up to 20 K – bringing them into better agreement with satellite temperatures. Following the description of the algorithm is a 20-year cross-validation of two lidars which establishes the stability of the technique.
Irene Crisologo, Robert A. Warren, Kai Mühlbauer, and Maik Heistermann
Atmos. Meas. Tech., 11, 5223–5236,Short summary
The calibration of ground-based weather radar (GR) can be improved a posteriori by comparing observed GR reflectivity to well-established spaceborne radar platforms (SR), such as TRMM or GPM. Our study shows that the consistency between GR and SR reflectivity measurements can be enhanced by considering the quality of GR data from areas where signals may have been blocked due to the surrounding terrain, and provides an open-source toolset to carry out corresponding analyses.
Manuel F. Rios Gaona, Aart Overeem, Timothy H. Raupach, Hidde Leijnse, and Remko Uijlenhoet
Atmos. Meas. Tech., 11, 4465–4476,Short summary
Rainfall estimates from commercial microwave links were obtained for the city of Sao Paulo (Brazil). The results show the potential of such networks as complementary rainfall measurements for more robust networks (e.g. radars, gauges, satellites).
Therese Rieckh and Richard Anthes
Atmos. Meas. Tech., 11, 4309–4325,Short summary
We compare the two-cornered hat (2CH) and three-cornered hat (3CH) method for estimating the error variances of two or more independent data sets using simulated data with various error correlations and biases. We assess the accuracy of the 3CH and 2CH estimates and examine the sensitivity of the estimated error variances to the degree of error correlation between the data sets as well as sample size. The 3CH method is less sensitive to these factors and hence more accurate.
Nicola Bodini, Julie K. Lundquist, and Rob K. Newsom
Atmos. Meas. Tech., 11, 4291–4308,Short summary
Turbulence within the atmospheric boundary layer is critically important to transfer heat, momentum, and moisture. Currently, improved turbulence parametrizations are crucially needed to refine the accuracy of model results at fine horizontal scales. In this study, we calculate turbulence dissipation rate from sonic anemometers and discuss a novel approach to derive turbulence dissipation from profiling lidar measurements.
Martin Burgdorf, Imke Hans, Marc Prange, Theresa Lang, and Stefan A. Buehler
Atmos. Meas. Tech., 11, 4005–4014,Short summary
We analysed observations of the Moon with the Advanced Microwave Sounding Unit-B on the NOAA-16 satellite in order to search for bias in the sounding channels. Significant bias had been detected in the past on the basis of simultaneous nadir overpasses. With the Moon providing a quite different reference flux than the on-board calibration target and Earth scenes, radio-frequency interference emerged as the best explanation for the anomalies of channel 20 of AMSU-B on NOAA-16.
Daniel Wolfensberger and Alexis Berne
Atmos. Meas. Tech., 11, 3883–3916,Short summary
This work presents a polarimetric forward operator for the COSMO weather prediction model. This tool is able to simulate radar observables from the state of the atmosphere simulated by the model, taking into account most physical aspects of radar beam propagation and backscattering. This operator was validated with a large dataset of radar observations from several instruments and it was shown that is able to simulate a realistic radar signature in liquid precipitation.
Therese Rieckh, Richard Anthes, William Randel, Shu-Peng Ho, and Ulrich Foelsche
Atmos. Meas. Tech., 11, 3091–3109,Short summary
Water vapor is the most important tropospheric greenhouse gas and is also highly variable in space and time. We study the vertical structure and variability of tropospheric humidity using various observing techniques (GPS radio occultation, radiosondes, Atmospheric Infrared Sounder) and models. Time–height cross sections reveal seasonal biases for different pressure layers. We find that radio occultation humidity has high accuracy and can contribute valuable information in data assimilation.
Shay Gilpin, Therese Rieckh, and Richard Anthes
Atmos. Meas. Tech., 11, 2567–2582,Short summary
Comparing observational systems when observations are not taken at the exact same time or location can introduce sampling errors that can be come significant during error analysis. In this study, we develop two methods to reduce sampling errors: using ellipse distance constraints rather than circles and subtracting model background. We found that both the ellipses and subtracting model background from the observations reduce sampling errors caused by spatial and temporal differences.
Xiao Yu, Feiqin Xie, and Chi O. Ao
Atmos. Meas. Tech., 11, 2051–2066,Short summary
Atmospheric observations from GPS receiver satellites offer uniform spatial coverage over the Arctic. The GPS profiles sensing deep into the lowest 300 m of the atmosphere only reach 50–60 % in summer but over 70 % in other seasons. The profile uncertainty due to different data centers is within 0.07 % in refractivity, 0.72 K in temperature, and 0.05 g kg-1 in humidity below 10 km. A systematic negative bias of 1 % in refractivity below 2 km is only seen in the summer due to moisture impact.
Getachew Tesfaye Ayehu, Tsegaye Tadesse, Berhan Gessesse, and Tufa Dinku
Atmos. Meas. Tech., 11, 1921–1936,Short summary
The intent of this research paper is to rigorously validate the performance of satellite rainfall products to be used for various operational applications in data-scarce regions of the Upper Blue Nile (UBN) basin in Ethiopia. It was found that satellite rainfall products could be used as an alternative source of rainfall data in areas with no or poor ground observations. Their reliable performance could make more appropriate for various functions in complex topographic areas of the UBN basin.
Rolf Rüfenacht, Gerd Baumgarten, Jens Hildebrand, Franziska Schranz, Vivien Matthias, Gunter Stober, Franz-Josef Lübken, and Niklaus Kämpfer
Atmos. Meas. Tech., 11, 1971–1987,Short summary
Wind information throughout the middle-atmosphere is crucial for the understanding of atmospheric dynamics but became available only recently, thanks to developments in remote sensing and modelling approaches. We present the first thorough assessment of the quality of the wind estimates by comparing co-located observations from lidar and microwave radiometry and opposing them to the major atmospheric models. Moreover we evaluated a new approach for measuring mesopause region wind by radiometry.
Julian Liman, Marc Schröder, Karsten Fennig, Axel Andersson, and Rainer Hollmann
Atmos. Meas. Tech., 11, 1793–1815,Short summary
Latent heat fluxes (LHF) play a major role in the climate system. Over open ocean, they are increasingly observed by satellite instruments. To access their quality, this research focuses on thorough uncertainty analysis of all LHF-related variables of the HOAPS satellite climatology, in parts making use of novel analysis approaches. Results indicate climatological LHF uncertainies up to 50 W m−2, whereby underlying specific humidities tend to be more uncertain than contributing wind speeds.
Panagiotis Vergados, Anthony J. Mannucci, Chi O. Ao, Olga Verkhoglyadova, and Byron Iijima
Atmos. Meas. Tech., 11, 1193–1206,Short summary
This study cross-compares the 10-year record of GPS radio occultation (GPS-RO) specific humidity product against independent databases (e.g., AIRS satellite, NASA/MERRA, and ERA-Interim). Our objective is to investigate the suitability of the GPS-RO humidity as a climate variable, which the science community could use in climate research. GPS-RO offers high vertical resolution, low sensitivity to clouds, and long-term stability making GPS-RO humidity a valuable complementary data set.
Markus Rapp, Andreas Dörnbrack, and Bernd Kaifler
Atmos. Meas. Tech., 11, 1031–1048,Short summary
Temperature profiles from operational weather satellites are used to determine the global distribution of gravity wave activity. This is an important information to constrain global climate models. The quality of this data set is assessed by systematic comparison to model fields from ECMWF which are considered very high quality. This reveals good agreement between model and observations, albeit the model misses localized centers of wave activity if model resolution is too low.
Panagiotis G. Kosmopoulos, Stelios Kazadzis, Michael Taylor, Panagiotis I. Raptis, Iphigenia Keramitsoglou, Chris Kiranoudis, and Alkiviadis F. Bais
Atmos. Meas. Tech., 11, 907–924,Short summary
Continuous monitoring of solar energy from space is critical for its efficient exploitation and distribution. For this reason we developed neural-network- and function-based real-time models, which are capable of producing massive radiation outputs in high spectral, spatial and temporal resolution. The models' performance against ground-based measurements revealed a dependence on input quality and resolution, and an overall accuracy under cloudless and high solar energy potential conditions.
Feiqin Xie, Loknath Adhikari, Jennifer S. Haase, Brian Murphy, Kuo-Nung Wang, and James L. Garrison
Atmos. Meas. Tech., 11, 763–780,Short summary
The GPS signal going through the atmosphere will experience refraction or bending, which can be precisely measured and used to infer the atmospheric properties. This paper demonstrates that high-quality atmospheric measurement with less than ~ 0.4 K is achievable from a GPS recording system with a simple antenna mounted on top of an aircraft cruising at ~ 13 km. Such a simple airborne GPS system can be implemented on commercial aircraft to provide valuable data for weather models in the future.
Catrin I. Meyer, Manfred Ern, Lars Hoffmann, Quang Thai Trinh, and M. Joan Alexander
Atmos. Meas. Tech., 11, 215–232,Short summary
We investigate stratospheric gravity wave observations by the Atmospheric InfraRed Sounder (AIRS) and the High Resolution Dynamics Limb Sounder (HIRDLS). Waves seen by AIRS contribute significantly to momentum flux, which indicates a calculated momentum flux factor. AIRS and HIRDLS agree well in the phase structure of the wave events and also in the seasonal and latitudinal patterns of gravity wave activity and can be used complementary to each other.
Elena Castillo-López, Jose Antonio Dominguez, Raúl Pereda, Julio Manuel de Luis, Ruben Pérez, and Felipe Piña
Atmos. Meas. Tech., 10, 3919–3929,Short summary
This work is part of a project funded by the government of Spain, whose objective was to develop a methodology that would allow the grain size and heavy metals estimation in the sediments of the intertidal zone (Bay of Santander) and depth estimation in the subtidal area, using information (VNIR) captured by the hyperspectral sensor, CASI-2, a spectroradiometer ASD-FR (350–2500 nm) in field and laboratory and classical and robust statistic algorithms.
Pauline Martinet, Domenico Cimini, Francesco De Angelis, Guylaine Canut, Vinciane Unger, Remi Guillot, Diane Tzanos, and Alexandre Paci
Atmos. Meas. Tech., 10, 3385–3402,Short summary
Microwave radiometers have the capability of observing temperature and humidity profiles with a few minute time resolution. This study investigates the potential benefit of this instrument to improve weather forecasts thanks to a better initialization of the model. Our results show that a significant improvement can be expected in the model initialization in the first 3 km with potential impacts on weather forecasts.
Anthes, R. A., Ector, D., Hunt, D. C., Kuo, Y.-H., Rocken, C., Schreiner, W. S., Sokolovskiy, S. V., Syndergaard, S., Wee, T.-K., Zeng, Z., Bernhardt, P. A., Dymond, K. F., Chen, Y., Liu, H., Manning, K., Randel, W. J., Trenberth, K. E., Cucurull, L., Healy, S. B., Ho, S.-P., McCormic, C., Meehan, T. K., Thompson, D. C., and Yen, N. L.: The COSMIC/FORMOSAT-3 mission: Early results, B. Am. Meteorol. Soc., 89, 313–333, 2008.
Aparicio, J. M., Deblonde, G., Garand, L., and Laroche, S.: The signature of the atmospheric compressibility factor in COSMIC, CHAMP and GRACE radio occultation data, J. Geophys. Res., 114, D16144, https://doi.org/10.1029/2008JD011156, 2009.
Buontempo, C., Jupp, A., and Rennie, M. P.: Operational NWP assimilation of GPS radio occultation data, Atmos. Sci. Lett., 9, 129–133, 2008.
Chen, F. and Dudhia, J.: Coupling an advanced land surface-hydrology model with the Penn State-NCAR MM5 modeling system. Part I: Model implementation and sensitivity, Mon. Weather Rev., 129, 569–585, 2001.
Cucurull, L. and Derber, J. C.: Operational implementation of COSMIC observations into NCEP's global data assimilation system, Weather Forecast., 23, 702–711, 2008.
Cucurull, L., Derber, J. C., Treadon, R., and Purser, R. J.: Assimilation of Global Positioning System Radio Occultation Observations into NCEP's Global Data Assimilation System, Mon. Weather Rev., 135, 3174–3193, 2007.
Galarneau, T. J. and Davis, C. A.: Diagnosing forecast errors in tropical cyclone motion, Mon. Weather Rev., 141, 405–430, 2013.
Hajj, G. A., Ao, C. O., Iijima, B. A., Kuang, D., Kursinski, E. R., Mannucci, A. J., Meehan, T. K., Romans, L. J., Juarez, M. de la Torre, and Yunck, T. P.: CHAMP and SAC-C atmospheric occultation results and intercomparisons, J. Geophys. Res., 109, D06109, https://doi.org/10.1029/2003JD003909, 2004.
Healy, S. B.: Forecast impact experiment with a constellation of GPS radio occultation receivers, Atmos. Sci. Lett., 9, 111–118, 2008.
Ho, S.-P., Kerchengast, G., Leroy, S., Wickert, J., Mannucci, A. J., Steiner, A., Hunt, D., Schreiner, W., Sokolovskiy, S., Ao, C., Borsche, M., von Engeln, A., Foelsche, U., Heise, S., Iijima, B., Kuo, Y.-H., Kursinski, R., Pirscher, B., Ringer, M., Rocken, C., and Schmidt, T.: Estimating the uncertainty of using GPS radio occultation data for climate monitoring: Intercomparison of CHAMP refractivity climate records from 2002 to 2006 from different data centers, J. Geophys. Res., 114, D23107, https://doi.org/10.1029/2009JD011969, 2009.
Hong, S.-Y., Noh, Y., and Dudhia, J.: A new vertical diffusion package with an explicit treatment of entrainment processes, Mon. Weather Rev., 134, 2318–2341, 2006.
Hsiao, L.-F., Chen, D.-S., Kuo, Y.-H., Guo, Y.-R., Yeh, T.-C., Hong, J.-S., Fong, C.-T., and Lee, C.-S.: Application of WRF 3DVAR to operational typhoon prediction in Taiwan: impact of outer loop and partial cycling approaches, Weather Forecast., 27, 1249–1263, 2012.
Huang, C.-Y., Kuo, Y.-H., and Chen, S.-H.: Improvements on Typhoon Forecast with Assimilated GPS Occultation Refractivity, Weather Forecast., 20, 931–953, 2005.
Kain, J. S. and Fritsch, J. M.: A one-dimensional entraining/detraining plume model and its application in convective parameterization, J. Atmos. Sci., 47, 2784–2802, 1990.
Kueh, M.-T., Huang, C.-Y., Chen, S.-Y., Chen, S.-H., and Wang, C.-J.: Impact of GPS radio occultation soundings on prediction of Typhoon Bilis (2006) landfalling Taiwan, Terr. Atmos. Ocean Sci., 20, 115–131, 2009.
Kuo, Y.-H., Zou, X., and Huang, W.: The impact of Global Positioning System data on the prediction of an extratropical cyclone: An observing system simulation experiment, Dynam. Atmos. Oceans, 27, 439–470, 1997.
Kuo, Y.-H., Wee, T.-K., Sokolovskiy, S., Rocken, C., Schreiner, W., Hunt, D., and Anthes, R. A.: Inversion and error estimation of GPS radio occultation data, J. Meteorol. Soc. Jpn., 82, 507–531, 2004.
Kuo, Y.-H., Liu, H., Guo, Y.-R., Terng, C.-T., and Lin. Y.-T.: Impact of FORMOSAT-3/COSMIC data on typhoon and Mei-yu prediction, in: Recent Progress in Atmospheric Sciences: Applications to the Asia-Pacific Region, World Scientific, 458–483, 2009.
Kursinski, E. R., Hajj, G. A., Hardy, K. R., Schofield, J. T., and Linfield, R.: Observing Earth's atmosphere with radio occultation measurements, J. Geophys. Res., 102, 23429–23465, 1997.
Landsea, C. W. and Franklin, J. L.: Atlantic Hurricane Database Uncertainty and Presentation of a New Dataset Format, Mon. Weather Rev., 141, 3576–3592, 2013.
Larsen, G. B., Lauritsen, K. B., Rubek, F., and Sorensen, M. B.: GRAS-SAF Radio Occultation Data from EPS/Metop, in: Occultation for Probing Atmosphere and Climate, Kirchengast, G., Foelsche, U., and Steiner, A. K., Springer, 111–118, 2004.
Liu, H., Anderson, J., and Kuo, Y.-H.: Improved Analyses and Forecasts of Hurricane Ernesto's Genesis Using Radio Occultation Data in an Ensemble Filter Assimilation System, Mon. Weather Rev., 140, 151–166, 2012.
Mlawer, E. J., Taubman, S. J., Brown, P. D., Iacono, M. J., and Clough, S. A.: Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave, J. Geophys. Res., 102, 16663–16682, 1997.
Poli, P., Healy, S. B., and Dee, D. P.: Assimilation of Global Positioning System radio occultation data in the ECMWF ERA-Interim reanalysis, Q. J. Roy. Meteor. Soc., 136, 1972–1990, https://doi.org/10.1002/qj.722, 2010.
Shen, Y.-C., Chen, Y.-C., Yang, M.-J., Fong, C.-T., and Chen, W.-M.: The Impacts of GPSRO data to the forecast typhoon tracks in Central Weather Bureau's Global Forecast System, 2011 Conference on Weather Analysis, Forecasting and Seismic Observation, Taipei, Taiwan, 20–22 September 2011, 90–93, 2011 (in Chinese).
Smith, E. K. and Weintraub, S.: The constants in the equation for atmospheric refractive index at radio frequencies, P. IRE, 41, 1035–1037, 1953.
Tao, W.-K., Simpson, J., Baker, D., Braun, S., Chou, M.-D., Ferrier, B., Johnson, D., Khain, A., Lang, S., Lynn, B., Shie, C.-L., Starr, D., Sui, C.-H., Wang, Y., and Wetzel, P.: Microphysics, radiation and surface processes in the Goddard Cumulus Ensemble (GCE) model, Meteorol. Atmos. Phys., 82, 97–137, 2003.
Ware, R., Rocken, C., Solheim, F., Exner, M., Schreiner, W., Anthes, R., Feng, D., Herman, B., Gorbunov, M., Sokolovskiy, S., Hardy, K., Kuo, Y., Zou, X., Trenberth, K., Meehan, T., Melbourne, W., and Businger, S.: GPS soundings of the atmosphere from low earth orbit: Preliminary results, B. Am. Meteorol. Soc., 77, 19–40, 1996.
Wickert, J., Reigber, C., Beyerle, G., König, R., Marquardt, C., Schmidt, T., Grunwaldt, L., Galas, R., Meehan, T. K., and Melbourne, W. G.: Atmosphere sounding by GPS radio occultation: First results from CHAMP, Geophys. Res. Lett., 28, 3263–3266, 2001.
Wickert, J., Arras, C., Ao, C. O., Beyerle, G., Falck, C., Grunwaldt, L., Healy, S. B., Heise, S., Helm, A., Huang, C.-Y., Jakowski, N., Konig, R., Mannucci, T., Mayer, C., Michalak, G., Poli, P., Rothacher, M., Schmidt, T., Stosius, R., and Tapley, B.: CHAMP, GRACE, SAC-C, TerraSAR-X/TanDEM-X: Science results, status and future prospects, GRAS SAF Workshop on Applications of GPSRO Measurements, ECMWF, 16–18 June 2008, 43–52, 2008.
We systematically evaluated the impact of GPSRO data on typhoon track prediction over the Northwestern Pacific during 2008 to 2010. Specifically, we perform data assimilation and forecast experiments using the TWRF system at 45km resolution on 11 typhoons, with or without the use of GPSRO refractivity. The results indicate that the assimilation of GPSRO reduces the 72-hour track forecast errors by ~12km (5 %). Although this is only a modest improvement, it is statistically significant.
We systematically evaluated the impact of GPSRO data on typhoon track prediction over the...