Evaluating Sentinel-5P TROPOMI tropospheric NO2 column
densities with airborne and Pandora spectrometers near New York
City and Long Island Sound
Laura M. Judd, Jassim A. Al-Saadi, James J. Szykman, Lukas C. Valin, Scott J. Janz, Matthew G. Kowalewski, Henk J. Eskes, J. Pepijn Veefkind, Alexander Cede, Moritz Mueller, Manuel Gebetsberger, Robert Swap, R. Bradley Pierce, Caroline R. Nowlan, Gonzalo González Abad, Amin Nehrir, and David Williams
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-151,2020
Preprint under review for AMT (discussion: open, 0 comments)
This paper evaluates Sentinel-5P TROPOMI v1.2 NO2 tropospheric columns over New York City using data from airborne mapping spectrometers and a network of ground-based spectrometers (Pandora) collected in 2018. These evaluations consider impacts due to cloud parameters, a priori profile assumptions, and spatial/temporal variability. Overall, TROPOMI tropospheric NO2 columns appear to have a low bias in this region.
Interannual and seasonal variations in aerosol optical depth of the atmosphere in two regions of Spitsbergen Archipelago (2002–2018)
Dmitry M. Kabanov, Christoph Ritter, and Sergey M. Sakerin
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-83,2020
Preprint under review for AMT (discussion: open, 0 comments)
Long-term photometer measurements of two sites in the European Arctic on the archipelago of Spitsbergen, Barentsburg and Ny-Alesund are presented and compared. We find slightly higher aerosol optical depths at Barentsburg and attribute this to a higher concentration of small particles.
Validation of Aeolus wind products above the Atlantic Ocean
Holger Baars, Alina Herzog, Birgit Heese, Kevin Ohneiser, Karsten Hanbuch, Julian Hofer, Zhenping Yin, Ronny Engelmann, and Ulla Wandinger
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-198,2020
Preprint under review for AMT (discussion: open, 0 comments)
We present validation measurements for the European Satellite Aeolus which was launched in August 2018. Aeolus measures horizontal wind profiles around the globe.
We utilized radiosonde launches onboard the German research vessel Polarstern to validate the Aeolus observations on the Atlantic Ocean – a region were almost no other validation measurements are available. It is shown, that Aeolus is able to measure accurately atmospheric winds and thus may significantly improve weather forecast.
Measurement of NOx and NOy with a thermal dissociation cavity ring-down spectrometer (TD-CRDS): Instrument characterisation and first deployment
Nils Friedrich, Ivan Tadic, Jan Schuladen, James Brooks, Eoghan Darbyshire, Frank Drewnick, Horst Fischer, Jos Lelieveld, and John N. Crowley
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-187,2020
Preprint under review for AMT (discussion: open, 0 comments)
We present a new instrument for measurement of NOx and NOy based on a combination of thermal dissociation of NOy to NOx and cavity-ringdown-spectroscopy detection of NO2. It features a denuder to separate contributions of gas-phase and particulate nitrates to NOy. We describe a detailed characterization of the instrument and briefly outline results from first deployments.
Validation of Aeolus wind products above the Atlantic Ocean
Holger Baars, Alina Herzog, Birgit Heese, Kevin Ohneiser, Karsten Hanbuch, Julian Hofer, Zhenping Yin, Ronny Engelmann, and Ulla Wandinger
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-198,2020
Preprint under review for AMT (discussion: open, 0 comments)
We present validation measurements for the European Satellite Aeolus which was launched in August 2018. Aeolus measures horizontal wind profiles around the globe.
We utilized radiosonde launches onboard the German research vessel Polarstern to validate the Aeolus observations on the Atlantic Ocean – a region were almost no other validation measurements are available. It is shown, that Aeolus is able to measure accurately atmospheric winds and thus may significantly improve weather forecast.
Measurement of NOx and NOy with a thermal dissociation cavity ring-down spectrometer (TD-CRDS): Instrument characterisation and first deployment
Nils Friedrich, Ivan Tadic, Jan Schuladen, James Brooks, Eoghan Darbyshire, Frank Drewnick, Horst Fischer, Jos Lelieveld, and John N. Crowley
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-187,2020
Preprint under review for AMT (discussion: open, 0 comments)
We present a new instrument for measurement of NOx and NOy based on a combination of thermal dissociation of NOy to NOx and cavity-ringdown-spectroscopy detection of NO2. It features a denuder to separate contributions of gas-phase and particulate nitrates to NOy. We describe a detailed characterization of the instrument and briefly outline results from first deployments.
Airborne measurement of peroxy radicals using chemical amplification coupled with cavity ring-down spectroscopy: the PeRCEAS instrument
Midhun George, Maria Dolores Andrés Hernández, Vladyslav Nenakhov, Yangzhuoran Liu, and John Philip Burrows
Atmos. Meas. Tech., 13, 2577–2600, https://doi.org/10.5194/amt-13-2577-2020, 2020
The accurate measurement of peroxy radicals is essential for understanding the chemistry of air masses probed in the free troposphere. The PeRCEAS instrument has been designed, developed and thoroughly characterised for the measurement of the total sum of peroxy radicals (RO2*) aboard airborne platforms. Parameters expected to affect the precision and accuracy of the measurement have been investigated in detail.
Consistency and structural uncertainty of multi-mission GPS radio occultation records
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, https://doi.org/10.5194/amt-13-2547-2020, 2020
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.
Airborne measurement of peroxy radicals using chemical amplification coupled with cavity ring-down spectroscopy: the PeRCEAS instrument
Midhun George, Maria Dolores Andrés Hernández, Vladyslav Nenakhov, Yangzhuoran Liu, and John Philip Burrows
Atmos. Meas. Tech., 13, 2577–2600, https://doi.org/10.5194/amt-13-2577-2020, 2020
The accurate measurement of peroxy radicals is essential for understanding the chemistry of air masses probed in the free troposphere. The PeRCEAS instrument has been designed, developed and thoroughly characterised for the measurement of the total sum of peroxy radicals (RO2*) aboard airborne platforms. Parameters expected to affect the precision and accuracy of the measurement have been investigated in detail.
Consistency and structural uncertainty of multi-mission GPS radio occultation records
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, https://doi.org/10.5194/amt-13-2547-2020, 2020
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.
Development of on-site self-calibration and retrieval methods for sky-radiometer observations of precipitable water vapor
Masahiro Momoi, Rei Kudo, Kazuma Aoki, Tatsuhiro Mori, Kazuhiko Miura, Hiroshi Okamoto, Hitoshi Irie, Yoshinori Shoji, Akihiro Uchiyama, Osamu Ijima, Matsumi Takano, and Teruyuki Nakajima
Atmos. Meas. Tech., 13, 2635–2658, https://doi.org/10.5194/amt-13-2635-2020, 2020
The water vapor channel of sun photometers, such as a sky radiometer, has been calibrated at limited observation sites (e.g., Mauna Loa) in previous studies, but our procedure has made on-site calibration possible by using sky radiances in addition to direct solar irradiance. The retrieved precipitable water vapor values correspond well to those derived from a global-navigation-satellite-system–global-positioning-system receiver, a microwave radiometer, and an AERONET sun–sky radiometer.
Aerosol retrievals from the EKO MS-711 spectral direct irradiance measurements and corrections of the circumsolar radiation
Rosa Delia García-Cabrera, Emilio Cuevas-Agulló, África Barreto, Victoria Eugenia Cachorro, Mario Pó, Ramón Ramos, and Kees Hoogendijk
Atmos. Meas. Tech., 13, 2601–2621, https://doi.org/10.5194/amt-13-2601-2020, 2020
Spectral direct UV–visible normal solar irradiance, measured with an EKO MS-711 grating spectroradiometer at the Izaña Atmospheric Observatory (Spain), has been used to determine aerosol optical depth (AOD) at several wavelengths, and has been compared to synchronous AOD measurements from a reference AERONET (Aerosol RObotic NETwork) Cimel sun photometer.
Simultaneous measurements of the relative-humidity-dependent aerosol light extinction, scattering, absorption, and single-scattering albedo with a humidified cavity-enhanced albedometer
Jiacheng Zhou, Xuezhe Xu, Weixiong Zhao, Bo Fang, Qianqian Liu, Yuanqing Cai, Weijun Zhang, Dean S. Venables, and Weidong Chen
Atmos. Meas. Tech., 13, 2623–2634, https://doi.org/10.5194/amt-13-2623-2020, 2020
We report the first demonstration of a humidified cavity-enhanced albedometer (H-CEA) that combines a broadband cavity-enhanced aerosol albedometer with a humidigraph system for simultaneous and accurate measurements of multiple optical hygroscopic parameters (f(RH)ext,scat,abs,ω) at λ = 532 nm. The instrument is suitable for operating under high RH-conditions and has sampling advantages over independent measurements of different parameters with different instruments.
TanSat ACGS on-orbit spectral calibration by use of individual
solar lines and entire atmospheric spectra
Yanmeng Bi, Qian Wang, Zhongdong Yang, Chengbao Liu, Chao Lin, Longfei Tian, Naiqiang Zhang, Yanping Luo, and Yacheng Wang
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-20,2020
Preprint under review for AMT (discussion: open, 0 comments)
We have used two types of on-orbit methods to evaluate the TANSAT/ACGS wavelength calibration. The first method is to use the solar Fraunhofer absorption lines as the reference.The second method uses the entire atmospheric spectra as the reference.For TanSat ACGS, the wavelength variations derived from the two methods agree closely. The accuracy of wavelength offsets is better than 10 % of the FWHM that meet the requirements of spectral calibration of the ACGS on orbit.
Hydrometeor classification of quasi-vertical profiles of polarimetric
radar measurements using a top-down iterative hierarchical
clustering method
Maryna Lukach, David Dufton, Jonathan Crosier, Joshua M. Hampton, Lindsay Bennett, and Ryan R. Neely III
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-143,2020
Preprint under review for AMT (discussion: open, 0 comments)
This paper presents a novel technique of data-driven hydrometeor classification (HC) from QVPs, where the hydrometeor types are identified from an optimal number of hierarchical clusters, obtained recursively. This data-driven HC approach is capable of providing an optimal number of classes from the dual-polarimetric weather radar observations and the embedded flexibility in the extent of granularity is the main advantage of this technique.
Development of on-site self-calibration and retrieval methods for sky-radiometer observations of precipitable water vapor
Masahiro Momoi, Rei Kudo, Kazuma Aoki, Tatsuhiro Mori, Kazuhiko Miura, Hiroshi Okamoto, Hitoshi Irie, Yoshinori Shoji, Akihiro Uchiyama, Osamu Ijima, Matsumi Takano, and Teruyuki Nakajima
Atmos. Meas. Tech., 13, 2635–2658, https://doi.org/10.5194/amt-13-2635-2020, 2020
The water vapor channel of sun photometers, such as a sky radiometer, has been calibrated at limited observation sites (e.g., Mauna Loa) in previous studies, but our procedure has made on-site calibration possible by using sky radiances in addition to direct solar irradiance. The retrieved precipitable water vapor values correspond well to those derived from a global-navigation-satellite-system–global-positioning-system receiver, a microwave radiometer, and an AERONET sun–sky radiometer.
Aerosol retrievals from the EKO MS-711 spectral direct irradiance measurements and corrections of the circumsolar radiation
Rosa Delia García-Cabrera, Emilio Cuevas-Agulló, África Barreto, Victoria Eugenia Cachorro, Mario Pó, Ramón Ramos, and Kees Hoogendijk
Atmos. Meas. Tech., 13, 2601–2621, https://doi.org/10.5194/amt-13-2601-2020, 2020
Spectral direct UV–visible normal solar irradiance, measured with an EKO MS-711 grating spectroradiometer at the Izaña Atmospheric Observatory (Spain), has been used to determine aerosol optical depth (AOD) at several wavelengths, and has been compared to synchronous AOD measurements from a reference AERONET (Aerosol RObotic NETwork) Cimel sun photometer.
Simultaneous measurements of the relative-humidity-dependent aerosol light extinction, scattering, absorption, and single-scattering albedo with a humidified cavity-enhanced albedometer
Jiacheng Zhou, Xuezhe Xu, Weixiong Zhao, Bo Fang, Qianqian Liu, Yuanqing Cai, Weijun Zhang, Dean S. Venables, and Weidong Chen
Atmos. Meas. Tech., 13, 2623–2634, https://doi.org/10.5194/amt-13-2623-2020, 2020
We report the first demonstration of a humidified cavity-enhanced albedometer (H-CEA) that combines a broadband cavity-enhanced aerosol albedometer with a humidigraph system for simultaneous and accurate measurements of multiple optical hygroscopic parameters (f(RH)ext,scat,abs,ω) at λ = 532 nm. The instrument is suitable for operating under high RH-conditions and has sampling advantages over independent measurements of different parameters with different instruments.
TanSat ACGS on-orbit spectral calibration by use of individual
solar lines and entire atmospheric spectra
Yanmeng Bi, Qian Wang, Zhongdong Yang, Chengbao Liu, Chao Lin, Longfei Tian, Naiqiang Zhang, Yanping Luo, and Yacheng Wang
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-20,2020
Preprint under review for AMT (discussion: open, 0 comments)
We have used two types of on-orbit methods to evaluate the TANSAT/ACGS wavelength calibration. The first method is to use the solar Fraunhofer absorption lines as the reference.The second method uses the entire atmospheric spectra as the reference.For TanSat ACGS, the wavelength variations derived from the two methods agree closely. The accuracy of wavelength offsets is better than 10 % of the FWHM that meet the requirements of spectral calibration of the ACGS on orbit.
Hydrometeor classification of quasi-vertical profiles of polarimetric
radar measurements using a top-down iterative hierarchical
clustering method
Maryna Lukach, David Dufton, Jonathan Crosier, Joshua M. Hampton, Lindsay Bennett, and Ryan R. Neely III
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-143,2020
Preprint under review for AMT (discussion: open, 0 comments)
This paper presents a novel technique of data-driven hydrometeor classification (HC) from QVPs, where the hydrometeor types are identified from an optimal number of hierarchical clusters, obtained recursively. This data-driven HC approach is capable of providing an optimal number of classes from the dual-polarimetric weather radar observations and the embedded flexibility in the extent of granularity is the main advantage of this technique.
