First validation of Aeolus wind observations by airborne Doppler wind lidar measurements
Benjamin Witschas, Christian Lemmerz, Alexander Geiß, Oliver Lux, Uwe Marksteiner, Stephan Rahm, Oliver Reitebuch, and Fabian Weiler
Atmos. Meas. Tech., 13, 2381–2396, https://doi.org/10.5194/amt-13-2381-2020, 2020
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.
Nitrate radical generation via continuous generation of dinitrogen pentoxide in a laminar flow reactor coupled to an oxidation flow reactor
Andrew T. Lambe, Ezra C. Wood, Jordan E. Krechmer, Francesca Majluf, Leah R. Williams, Philip L. Croteau, Manuela Cirtog, Anaïs Féron, Jean-Eudes Petit, Alexandre Albinet, Jose L. Jimenez, and Zhe Peng
Atmos. Meas. Tech., 13, 2397–2411, https://doi.org/10.5194/amt-13-2397-2020, 2020
We present a new method to continuously generate N2O5 in the gas phase that is injected into a reactor where it decomposes to generate nitrate radicals (NO3). To assess the applicability of the method towards different chemical systems, we present experimental and model characterization of the integrated NO3 exposure and other metrics as a function of operating conditions. We demonstrate the method by characterizing secondary organic aerosol particles generated from the β-pinene + NO3 reaction.
Single-photon laser-induced fluorescence detection of nitric oxide at sub-parts-per-trillion mixing ratios
Andrew W. Rollins, Pamela S. Rickly, Ru-Shan Gao, Thomas B. Ryerson, Steven S. Brown, Jeff Peischl, and Ilann Bourgeois
Atmos. Meas. Tech., 13, 2425–2439, https://doi.org/10.5194/amt-13-2425-2020, 2020
Nitric oxide (NO) is a key atmospheric constituent controlling atmospheric oxidation chemistry and tropospheric ozone formation. Existing instrumentation capable of quantifying NO at very low mixing ratios is uncommon and typically relies on chemiluminescence. We describe and demonstrate a new laser-based technique (LIF) with significant practical and technical advantages to CL. This technique is expected to allow for advances in understanding of atmospheric radical chemistry.
Mind the gap – Part 1: Accurately locating warm marine boundary layer clouds and precipitation using spaceborne radars
Katia Lamer, Pavlos Kollias, Alessandro Battaglia, and Simon Preval
Atmos. Meas. Tech., 13, 2363–2379, https://doi.org/10.5194/amt-13-2363-2020, 2020
According to ground-based radar observations, 50 % of liquid low-level clouds over the Atlantic extend below 1.2 km and are thinner than 400 m, thus limiting their detection from space. Using an emulator, we estimate that a 250 m resolution radar would capture cloud base better than the CloudSat radar which misses about 52 %. The more sensitive EarthCARE radar is expected to capture cloud cover but stretch cloud. This calls for the operation of interlaced pulse modes for future space missions.
Mind the gap – Part 1: Accurately locating warm marine boundary layer clouds and precipitation using spaceborne radars
Katia Lamer, Pavlos Kollias, Alessandro Battaglia, and Simon Preval
Atmos. Meas. Tech., 13, 2363–2379, https://doi.org/10.5194/amt-13-2363-2020, 2020
According to ground-based radar observations, 50 % of liquid low-level clouds over the Atlantic extend below 1.2 km and are thinner than 400 m, thus limiting their detection from space. Using an emulator, we estimate that a 250 m resolution radar would capture cloud base better than the CloudSat radar which misses about 52 %. The more sensitive EarthCARE radar is expected to capture cloud cover but stretch cloud. This calls for the operation of interlaced pulse modes for future space missions.
Microwave and submillimeter wave scattering of oriented ice particles
Manfred Brath, Robin Ekelund, Patrick Eriksson, Oliver Lemke, and Stefan A. Buehler
Atmos. Meas. Tech., 13, 2309–2333, https://doi.org/10.5194/amt-13-2309-2020, 2020
Microwave dual-polarization observations consistently show that larger atmospheric ice particles tend to have a preferred orientation. We provide a publicly available database of microwave and submillimeter wave scattering properties of oriented ice particles based on discrete dipole approximation scattering calculations. Detailed radiative transfer simulations, recreating observed polarization patterns, are additionally presented in this study.
Atmospheric observations of the water vapour continuum in the near-infrared windows between 2500 and 6600 cm−1
Jonathan Elsey, Marc D. Coleman, Tom D. Gardiner, Kaah P. Menang, and Keith P. Shine
Atmos. Meas. Tech., 13, 2335–2361, https://doi.org/10.5194/amt-13-2335-2020, 2020
Water vapour is an important component in trying to understand the flows of energy between the Sun and Earth, since it is opaque to radiation emitted by both the surface and the Sun. In this paper, we study how it absorbs sunlight by way of its continuum, a property which is poorly understood and with few measurements. Our results indicate that this continuum absorption may be more significant than previously thought, potentially impacting satellite observations and climate studies.
Vertical wind profiling from the troposphere to the lower mesosphere based on high-resolution heterodyne near-infrared spectroradiometry
Alexander V. Rodin, Dmitry V. Churbanov, Sergei G. Zenevich, Artem Y. Klimchuk, Vladimir M. Semenov, Maxim V. Spiridonov, and Iskander S. Gazizov
Atmos. Meas. Tech., 13, 2299–2308, https://doi.org/10.5194/amt-13-2299-2020, 2020
The paper presents a new technique in remote wind measurements that may potentially complement conventional aerological observations and eventually greatly improve our knowledge about our climate system, especially concerning processes related to troposphere–stratosphere coupling. The technique may be implemented at relatively low cost in various applications from meteorological observation posts to remote sensing spacecraft.
TROPOMI Aerosol Products: Evaluation and Observations of Synoptic Scale Carbonaceous Aerosol Plumes during 2018–2020
Omar Torres, Hiren Jethva, Changwoo Ahn, Glen Jaross, and Diego G. Loyola
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-124,2020
Preprint under review for AMT (discussion: open, 0 comments)
TROPOMI measures the amount of small suspended particles (aerosols). We describe initial results of aerosol measurements using a NASA algorithm that retrieves the UV Aerosol Index, as well as Aerosol Optical Depth and Single Scattering Albedo. An evaluation of derived products using sun-photometer observations shows close agreement. We also use these results to discuss important biomass burning and wildfire events around the world that got the attention of scientists and news media alike.
Improvement of numerical weather prediction model analysis during fog conditions through the assimilation of ground-based microwave radiometer observations: a 1D-Var study
Pauline Martinet, Domenico Cimini, Frédéric Burnet, Benjamin Ménétrier, Yann Michel, and Vinciane Unger
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-166,2020
Preprint under review for AMT (discussion: open, 0 comments)
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 model paving the way for improved fog forecasts in the future.
Microwave and submillimeter wave scattering of oriented ice particles
Manfred Brath, Robin Ekelund, Patrick Eriksson, Oliver Lemke, and Stefan A. Buehler
Atmos. Meas. Tech., 13, 2309–2333, https://doi.org/10.5194/amt-13-2309-2020, 2020
Microwave dual-polarization observations consistently show that larger atmospheric ice particles tend to have a preferred orientation. We provide a publicly available database of microwave and submillimeter wave scattering properties of oriented ice particles based on discrete dipole approximation scattering calculations. Detailed radiative transfer simulations, recreating observed polarization patterns, are additionally presented in this study.
Atmospheric observations of the water vapour continuum in the near-infrared windows between 2500 and 6600 cm−1
Jonathan Elsey, Marc D. Coleman, Tom D. Gardiner, Kaah P. Menang, and Keith P. Shine
Atmos. Meas. Tech., 13, 2335–2361, https://doi.org/10.5194/amt-13-2335-2020, 2020
Water vapour is an important component in trying to understand the flows of energy between the Sun and Earth, since it is opaque to radiation emitted by both the surface and the Sun. In this paper, we study how it absorbs sunlight by way of its continuum, a property which is poorly understood and with few measurements. Our results indicate that this continuum absorption may be more significant than previously thought, potentially impacting satellite observations and climate studies.
Vertical wind profiling from the troposphere to the lower mesosphere based on high-resolution heterodyne near-infrared spectroradiometry
Alexander V. Rodin, Dmitry V. Churbanov, Sergei G. Zenevich, Artem Y. Klimchuk, Vladimir M. Semenov, Maxim V. Spiridonov, and Iskander S. Gazizov
Atmos. Meas. Tech., 13, 2299–2308, https://doi.org/10.5194/amt-13-2299-2020, 2020
The paper presents a new technique in remote wind measurements that may potentially complement conventional aerological observations and eventually greatly improve our knowledge about our climate system, especially concerning processes related to troposphere–stratosphere coupling. The technique may be implemented at relatively low cost in various applications from meteorological observation posts to remote sensing spacecraft.
TROPOMI Aerosol Products: Evaluation and Observations of Synoptic Scale Carbonaceous Aerosol Plumes during 2018–2020
Omar Torres, Hiren Jethva, Changwoo Ahn, Glen Jaross, and Diego G. Loyola
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-124,2020
Preprint under review for AMT (discussion: open, 0 comments)
TROPOMI measures the amount of small suspended particles (aerosols). We describe initial results of aerosol measurements using a NASA algorithm that retrieves the UV Aerosol Index, as well as Aerosol Optical Depth and Single Scattering Albedo. An evaluation of derived products using sun-photometer observations shows close agreement. We also use these results to discuss important biomass burning and wildfire events around the world that got the attention of scientists and news media alike.
Improvement of numerical weather prediction model analysis during fog conditions through the assimilation of ground-based microwave radiometer observations: a 1D-Var study
Pauline Martinet, Domenico Cimini, Frédéric Burnet, Benjamin Ménétrier, Yann Michel, and Vinciane Unger
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-166,2020
Preprint under review for AMT (discussion: open, 0 comments)
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 model paving the way for improved fog forecasts in the future.
Stratospheric Extinction Profiles from SCIAMACHY Solar Occultation
Stefan Noël, Klaus Bramstedt, Alexei Rozanov, Elizaveta Malinina, Heinrich Bovensmann, and John P. Burrows
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-113,2020
Preprint under review for AMT (discussion: open, 0 comments)
A new approach to derive stratospheric aerosol extinction profiles between 15 and 30 km from SCIAMACHY solar occultation measurements is presented.
Except for some oscillating features the results for 452, 525 and 750 nm agree well with collocated SAGE II and SCIAMACHY limb data products.
Volcanic eruptions and polar stratospheric clouds can be identified in the time series.
Linear changes of extinction between 2003 and 2011 reach 20–30 % per year, mainly due to volcanic eruptions after 2006.
Quantifying the impact of aerosol scattering on the retrieval of methane from airborne remote sensing measurements
Yunxia Huang, Vijay Natraj, Zhaocheng Zeng, and Yuk L. Yung
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-51,2020
Preprint under review for AMT (discussion: open, 0 comments)
As a greenhouse gas with strong global warming potential, atmospheric methane emissions have attracted a great deal of attention. However, accurate assessment of these emissions is challenging in the presence of atmospheric particulates called aerosols. We quantify the aerosol impact on methane quantification from airborne measurements using two techniques, one that has traditionally been used by the imaging spectroscopy community and the other commonly employed in trace gas remote sensing.
Generalized Canonical Transform method for radio occultation sounding with improved retrieval in the presence of horizontal gradients
Michael Gorbunov, Gottfried Kirchengast, and Kent B. Lauritsen
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-147,2020
Preprint under review for AMT (discussion: open, 0 comments)
By now, the Canonical Transform (CT) approach to the processing of Radio Occultation (RO) observations is widely used. For the spherically symmetric atmosphere, the applicability of this method can be strictly proven. However, in the presence of horizontal gradients, this approach may not work. Here we introduce a generalization of the CT method in order to reduce the errors due to horizontal gradients.
Quantifying the impact of aerosol scattering on the retrieval of methane from airborne remote sensing measurements
Yunxia Huang, Vijay Natraj, Zhaocheng Zeng, and Yuk L. Yung
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-51,2020
Preprint under review for AMT (discussion: open, 0 comments)
As a greenhouse gas with strong global warming potential, atmospheric methane emissions have attracted a great deal of attention. However, accurate assessment of these emissions is challenging in the presence of atmospheric particulates called aerosols. We quantify the aerosol impact on methane quantification from airborne measurements using two techniques, one that has traditionally been used by the imaging spectroscopy community and the other commonly employed in trace gas remote sensing.
Generalized Canonical Transform method for radio occultation sounding with improved retrieval in the presence of horizontal gradients
Michael Gorbunov, Gottfried Kirchengast, and Kent B. Lauritsen
Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2020-147,2020
Preprint under review for AMT (discussion: open, 0 comments)
By now, the Canonical Transform (CT) approach to the processing of Radio Occultation (RO) observations is widely used. For the spherically symmetric atmosphere, the applicability of this method can be strictly proven. However, in the presence of horizontal gradients, this approach may not work. Here we introduce a generalization of the CT method in order to reduce the errors due to horizontal gradients.
