Articles | Volume 4, issue 10
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Sensitivity studies for a space-based methane lidar mission
Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, 82234 Oberpfaffenhofen, Germany
Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, 82234 Oberpfaffenhofen, Germany
Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, 82234 Oberpfaffenhofen, Germany
Related subject area
Subject: Gases | Technique: Remote Sensing | Topic: Instruments and PlatformsTheoretical assessment of the ability of the MicroCarb satellite city-scan observing mode to estimate urban CO2 emissionsUAV-based sampling systems to analyse greenhouse gases and volatile organic compounds encompassing compound-specific stable isotope analysisPerformance and polarization response of slit homogenizers for the GeoCarb missionExploring bias in the OCO-3 snapshot area mapping mode via geometry, surface, and aerosol effectsPrecipitable water vapor retrievals using a ground infrared sky camera in subtropical South AmericaUpdated spectral radiance calibration on TIR bands for TANSO-FTS-2 onboard GOSAT-2Evaluation of the High Altitude Lidar Observatory (HALO) methane retrievals during the summer 2019 ACT-America campaignPolarization performance simulation for the GeoXO atmospheric composition instrument: NO2 retrieval impactsThe impact of aerosol fluorescence on long-term water vapor monitoring by Raman lidar and evaluation of a potential correction methodIntegrated airborne investigation of the air composition over the Russian sector of the ArcticMeasurement of the vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMTQuantification and mitigation of the instrument effects and uncertainties of the airborne limb imaging FTIR GLORIAImproved calibration procedures for the EM27/SUN spectrometers of the COllaborative Carbon Column Observing Network (COCCON)Ground-based Ku-band microwave observations of ozone in the polar middle atmosphereTraceable total ozone column retrievals from direct solar spectral irradiance measurements in the ultravioletFar-ultraviolet airglow remote sensing measurements on Feng Yun 3-D meteorological satelliteThe NO2 camera based on gas correlation spectroscopyTotal water vapour columns derived from Sentinel 5P using the AMC-DOAS methodMobile and high-spectral-resolution Fabry–Pérot interferometer spectrographs for atmospheric remote sensingDiurnal variability of stratospheric column NO2 measured using direct solar and lunar spectra over Table Mountain, California (34.38° N)The “ideal” spectrograph for atmospheric observationsDifferential absorption lidar for water vapor isotopologues in the 1.98 µm spectral region: sensitivity analysis with respect to regional atmospheric variabilityAtmospheric carbon dioxide measurement from aircraft and comparison with OCO-2 and CarbonTracker model dataLong-term column-averaged greenhouse gas observations using a COCCON spectrometer at the high-surface-albedo site in Gobabeb, NamibiaA fully automated Dobson sun spectrophotometer for total column ozone and Umkehr measurementsSlit homogenizer introduced performance gain analysis based on the Sentinel-5/UVNS spectrometerOn the capability of the future ALTIUS ultraviolet–visible–near-infrared limb sounder to constrain modelled stratospheric ozoneMicroPulse DIAL (MPD) – a diode-laser-based lidar architecture for quantitative atmospheric profilingA multi-purpose, multi-rotor drone system for long-range and high-altitude volcanic gas plume measurementsTropospheric NO2 measurements using a three-wavelength optical parametric oscillator differential absorption lidarSpectral calibration of the MethaneAIR instrumentThe design and development of a tuneable and portable radiation source for in situ spectrometer characterisationPerformance of an open-path near-infrared measurement system for measurements of CO2 and CH4 during extended field trialsDetermination of the emission rates of CO2 point sources with airborne lidarThe GHGSat-D imaging spectrometerThermal and near-infrared sensor for carbon observation Fourier transform spectrometer-2 (TANSO-FTS-2) on the Greenhouse gases Observing SATellite-2 (GOSAT-2) during its first year in orbitPrediction model for diffuser-induced spectral features in imaging spectrometersCharacterization and potential for reducing optical resonances in Fourier transform infrared spectrometers of the Network for the Detection of Atmospheric Composition Change (NDACC)MUCCnet: Munich Urban Carbon Column networkEmission Monitoring Mobile Experiment (EMME): an overview and first results of the St. Petersburg megacity campaign 2019Effect of polyoxymethylene (POM-H Delrin) off-gassing within the Pandora head sensor on direct-sun and multi-axis formaldehyde column measurements in 2016–2019A powerful lidar system capable of 1 h measurements of water vapour in the troposphere and the lower stratosphere as well as the temperature in the upper stratosphere and mesosphereFirst high-resolution tropospheric NO2 observations from the Ultraviolet Visible Hyperspectral Imaging Spectrometer (UVHIS)Quantitative imaging of volcanic SO2 plumes using Fabry–Pérot interferometer correlation spectroscopyThree decades of tropospheric ozone lidar development at Garmisch-Partenkirchen, GermanySolar tracker with optical feedback and continuous rotationAssessment of global total column water vapor sounding using a spaceborne differential absorption radarIntercomparison of low- and high-resolution infrared spectrometers for ground-based solar remote sensing measurements of total column concentrations of CO2, CH4, and CORecommendations for spectral fitting of SO2 from miniature multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurementsAtmospheric ammonia (NH3) over the Paris megacity: 9 years of total column observations from ground-based infrared remote sensing
Kai Wu, Paul I. Palmer, Dien Wu, Denis Jouglet, Liang Feng, and Tom Oda
Atmos. Meas. Tech., 16, 581–602,Short summary
We evaluate the theoretical ability of the upcoming MicroCarb satellite to estimate urban CO2 emissions over Paris and London. We explore the relative performance of alternative two-sweep and three-sweep city observing modes and take into account the impacts of cloud cover and urban biological CO2 fluxes. Our results find both the two-sweep and three-sweep observing modes are able to reduce prior flux errors by 20 %–40 % depending on the prevailing wind direction and cloud coverage.
Simon Leitner, Wendelin Feichtinger, Stefan Mayer, Florian Mayer, Dustin Krompetz, Rebecca Hood-Nowotny, and Andrea Watzinger
Atmos. Meas. Tech., 16, 513–527,Short summary
An increased social environmental awareness requires the monitoring of greenhouse gases (GHGs). We report on the development of two sampling devices (which can be mounted to a drone) and the subsequent measurement setup to analyse these gases. The functionality of the presented system was tested in the field, and the results emphasised the functionality of the sampling and measurement setup, demonstrating that it is a viable tool for monitoring GHGs and identifying their emission sources.
Sean Crowell, Tobias Haist, Michael Tscherpel, Jérôme Caron, Eric Burgh, and Berrien Moore III
Atmos. Meas. Tech., 16, 195–208,Short summary
Variations in brightness in radiance measurements cause errors that can be mitigated with hardware that scrambles the pattern of the incoming light. GeoCarb took this route to minimize this source of errors, but lab testing determined that the solution chosen was too sensitive to the the polarization of the incoming light. Modeling found that this was a predictable result of using gold coatings in the design, which is typical of spaceflight optical instruments.
Emily Bell, Christopher W. O'Dell, Thomas E. Taylor, Aronne Merrelli, Robert R. Nelson, Matthäus Kiel, Annmarie Eldering, Robert Rosenberg, and Brendan Fisher
Atmos. Meas. Tech., 16, 109–133,Short summary
A small percentage of data from the Orbiting Carbon Observatory-3 (OCO-3) instrument has been shown to have a geometry-related bias in the earliest public data release. This work shows that the bias is due to a complex interplay of aerosols and viewing geometry and is largely mitigated in the latest data version through improved bias correction and quality filtering.
Elion Daniel Hack, Theotonio Pauliquevis, Henrique Melo Jorge Barbosa, Marcia Akemi Yamasoe, Dimitri Klebe, and Alexandre Lima Correia
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
Water vapor is a key factor when seeking to understand fast-changing processes when clouds and storms form and develop. We show here how images from a calibrated infrared camera can be used to derive how much water vapor there is in the atmosphere at a given time. Comparing our results to an established technique, for a case of stable atmospheric conditions, we found an agreement within 2.8 %. Water vapor sky maps can be retrieved every few minutes, day or night, and under partly cloudy skies.
Hiroshi Suto, Fumie Kataoka, Robert O. Knuteson, Kei Shiomi, Nobuhiro Kikuchi, and Akihiko Kuze
Atmos. Meas. Tech., 15, 5399–5413,Short summary
TANSO-FTS-2 onboard GOSAT-2 has operated nominally since February 2019, and the atmospheric radiance spectra it has acquired have been released to the public. This paper describes an updated model for spectral radiance calibration of TIR and its validation. The multi-satellite sensor and multi-angle comparison results suggest that the spectral radiance for TANSO-FTS-2 TIR, version v210210, is superior to that of the previous version in its consistency of multi-satellite sensor data.
Rory A. Barton-Grimley, Amin R. Nehrir, Susan A. Kooi, James E. Collins, David B. Harper, Anthony Notari, Joseph Lee, Joshua P. DiGangi, Yonghoon Choi, and Kenneth J. Davis
Atmos. Meas. Tech., 15, 4623–4650,Short summary
HALO is a multi-functional lidar that measures CH4 columns and profiles of H2O mixing ratio and aerosol/cloud optical properties. HALO supports carbon cycle, weather dynamics, and radiation science suborbital research and is a technology testbed for future space-based differential absorption lidar missions. In 2019 HALO collected CH4 columns and aerosol/cloud profiles during the ACT-America campaign. Here we assess HALO's CH4 accuracy and precision compared to co-located in situ observations.
Aaron Pearlman, Monica Cook, Boryana Efremova, Francis Padula, Lok Lamsal, Joel McCorkel, and Joanna Joiner
Atmos. Meas. Tech., 15, 4489–4501,Short summary
NOAA’s Geostationary Extended Observations (GeoXO) constellation is planned to consist of an atmospheric composition instrument (ACX) to support air quality forecasting and monitoring. As design trade-offs are being studied, we investigated one parameter, the polarization sensitivity, which has yet to be fully documented for NO2 retrievals. Our simulation study explores these impacts to inform the ACX’s development and better understand polarization’s role in trace gas retrievals.
Fernando Chouza, Thierry Leblanc, Mark Brewer, Patrick Wang, Giovanni Martucci, Alexander Haefele, Hélène Vérèmes, Valentin Duflot, Guillaume Payen, and Philippe Keckhut
Atmos. Meas. Tech., 15, 4241–4256,Short summary
The comparison of water vapor lidar measurements with co-located radiosondes and aerosol backscatter profiles indicates that laser-induced aerosol fluorescence in smoke layers injected into the stratosphere can introduce very large and chronic wet biases above 15 km, thus impacting the ability of these systems to accurately estimate long-term water vapor trends. The proposed correction method presented in this work is able to reduce this fluorescence-induced bias from 75 % to under 5 %.
Boris D. Belan, Gerard Ancellet, Irina S. Andreeva, Pavel N. Antokhin, Viktoria G. Arshinova, Mikhail Y. Arshinov, Yurii S. Balin, Vladimir E. Barsuk, Sergei B. Belan, Dmitry G. Chernov, Denis K. Davydov, Alexander V. Fofonov, Georgii A. Ivlev, Sergei N. Kotel'nikov, Alexander S. Kozlov, Artem V. Kozlov, Katharine Law, Andrey V. Mikhal'chishin, Igor A. Moseikin, Sergei V. Nasonov, Philippe Nédélec, Olesya V. Okhlopkova, Sergei E. Ol'kin, Mikhail V. Panchenko, Jean-Daniel Paris, Iogannes E. Penner, Igor V. Ptashnik, Tatyana M. Rasskazchikova, Irina K. Reznikova, Oleg A. Romanovskii, Alexander S. Safatov, Denis E. Savkin, Denis V. Simonenkov, Tatyana K. Sklyadneva, Gennadii N. Tolmachev, Semyon V. Yakovlev, and Polina N. Zenkova
Atmos. Meas. Tech., 15, 3941–3967,Short summary
The change of the global climate is most pronounced in the Arctic, where the air temperature increases faster than the global average. This is associated with an increase in the concentration of greenhouse gases in the atmosphere. It is important to study how the air composition in the Arctic changes in the changing climate. Thus this integrated experiment was carried out to measure the composition of the troposphere in the Russian sector of the Arctic from on board the aircraft laboratory.
Daochun Yu, Haitao Li, Baoquan Li, Mingyu Ge, Youli Tuo, Xiaobo Li, Wangchen Xue, Yaning Liu, Aoying Wang, Yajun Zhu, and Bingxian Luo
Atmos. Meas. Tech., 15, 3141–3159,Short summary
In this work, the measurement of vertical atmospheric density profiles using X-ray Earth occultation is investigated. The Earth’s density profile for the lower thermosphere is obtained with Insight-HXMT. It is shown that the Insight-HXMT X-ray satellite of China can be used as an X-ray atmospheric diagnostics instrument for the upper atmosphere. The Insight-HXMT satellite can, with other X-ray astronomical satellites in orbit, form a network for X-ray Earth occultation sounding in the future.
Jörn Ungermann, Anne Kleinert, Guido Maucher, Irene Bartolomé, Felix Friedl-Vallon, Sören Johansson, Lukas Krasauskas, and Tom Neubert
Atmos. Meas. Tech., 15, 2503–2530,Short summary
GLORIA is a 2-D infrared imaging spectrometer operated on two high-flying research aircraft. This paper details our instrument calibration and characterization efforts, which in particular leverage in-flight data almost exclusively and often exploit the novel 2-D nature of the measurements. We show that the instrument surpasses the original instrument specifications and conclude by analyzing how the derived errors affect temperature and ozone retrievals, two of our main derived quantities.
Carlos Alberti, Frank Hase, Matthias Frey, Darko Dubravica, Thomas Blumenstock, Angelika Dehn, Paolo Castracane, Gregor Surawicz, Roland Harig, Bianca C. Baier, Caroline Bès, Jianrong Bi, Hartmut Boesch, André Butz, Zhaonan Cai, Jia Chen, Sean M. Crowell, Nicholas M. Deutscher, Dragos Ene, Jonathan E. Franklin, Omaira García, David Griffith, Bruno Grouiez, Michel Grutter, Abdelhamid Hamdouni, Sander Houweling, Neil Humpage, Nicole Jacobs, Sujong Jeong, Lilian Joly, Nicholas B. Jones, Denis Jouglet, Rigel Kivi, Ralph Kleinschek, Morgan Lopez, Diogo J. Medeiros, Isamu Morino, Nasrin Mostafavipak, Astrid Müller, Hirofumi Ohyama, Paul I. Palmer, Mahesh Pathakoti, David F. Pollard, Uwe Raffalski, Michel Ramonet, Robbie Ramsay, Mahesh Kumar Sha, Kei Shiomi, William Simpson, Wolfgang Stremme, Youwen Sun, Hiroshi Tanimoto, Yao Té, Gizaw Mengistu Tsidu, Voltaire A. Velazco, Felix Vogel, Masataka Watanabe, Chong Wei, Debra Wunch, Marcia Yamasoe, Lu Zhang, and Johannes Orphal
Atmos. Meas. Tech., 15, 2433–2463,Short summary
Space-borne greenhouse gas missions require ground-based validation networks capable of providing fiducial reference measurements. Here, considerable refinements of the calibration procedures for the COllaborative Carbon Column Observing Network (COCCON) are presented. Laboratory and solar side-by-side procedures for the characterization of the spectrometers have been refined and extended. Revised calibration factors for XCO2, XCO and XCH4 are provided, incorporating 47 new spectrometers.
David A. Newnham, Mark A. Clilverd, William D. J. Clark, Michael Kosch, Pekka T. Verronen, and Alan E. E. Rogers
Atmos. Meas. Tech., 15, 2361–2376,Short summary
Ozone (O3) is an important trace gas in the mesosphere and lower thermosphere (MLT), affecting heating rates and chemistry. O3 profiles measured by the Ny-Ålesund Ozone in the Mesosphere Instrument agree with Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) for winter night-time, but autumn twilight SABER abundances are up to 50 % higher. O3 abundances in the MLT from two different SABER channels also show significant differences for both autumn twilight and summer daytime.
Luca Egli, Julian Gröbner, Gregor Hülsen, Herbert Schill, and René Stübi
Atmos. Meas. Tech., 15, 1917–1930,Short summary
This study presents traceable total column ozone retrievals from direct solar spectral irradiance measurements. The retrieved ozone does not require any field calibration with a reference instrument as it is required for other operational network instruments such as Brewer or Dobson. Total column ozone can be retrieved with a traceable overall standard uncertainty of less than 0.8 % indicating a benchmark uncertainty for total column ozone measurements.
Yungang Wang, Liping Fu, Fang Jiang, Xiuqing Hu, Chengbao Liu, Xiaoxin Zhang, Jiawei Li, Zhipeng Ren, Fei He, Lingfeng Sun, Ling Sun, Zhongdong Yang, Peng Zhang, Jingsong Wang, and Tian Mao
Atmos. Meas. Tech., 15, 1577–1586,Short summary
Far-ultraviolet (FUV) airglow radiation is particularly well suited for space-based remote sensing. The Ionospheric Photometer (IPM) instrument carried aboard the Feng Yun 3-D satellite measures the spectral radiance of the Earth FUV airglow. IPM is a tiny, highly sensitive, and robust remote sensing instrument. Initial results demonstrate that the performance of IPM meets the designed requirement and therefore can be used to study the thermosphere and ionosphere in the future.
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.
Tobias Küchler, Stefan Noël, Heinrich Bovensmann, John Philip Burrows, Thomas Wagner, Christian Borger, Tobias Borsdorff, and Andreas Schneider
Atmos. Meas. Tech., 15, 297–320,Short summary
We applied the air-mass-corrected differential optical absorption spectroscopy (AMC-DOAS) method to derive total column water vapour (TCWV) from Sentinel-5P measurements and compared it to independent data sets. The correlation coefficients of typically more than 0.9 and the small deviations up to 2.5 kg m−2 reveal good agreement between our data product and other TCWV data sets. In particular for the different Sentinel-5P water vapour products, the deviations are around 1 kg m−2.
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.
King-Fai Li, Ryan Khoury, Thomas J. Pongetti, Stanley P. Sander, Franklin P. Mills, and Yuk L. Yung
Atmos. Meas. Tech., 14, 7495–7510,Short summary
Nitrogen dioxide (NO2) plays a dominant role in the stratospheric ozone-destroying catalytic cycle. We have retrieved the diurnal cycle of NO2 over Table Mountain in Southern California, USA, during a week in October 2018. Under clean conditions, we are able to predict the diurnal cycle using standard photochemistry. On a day with significant pollution, we see the effect of NO2 sources in the nearby Los Angeles Basin.
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.
Jonas Hamperl, Clément Capitaine, Jean-Baptiste Dherbecourt, Myriam Raybaut, Patrick Chazette, Julien Totems, Bruno Grouiez, Laurence Régalia, Rosa Santagata, Corinne Evesque, Jean-Michel Melkonian, Antoine Godard, Andrew Seidl, Harald Sodemann, and Cyrille Flamant
Atmos. Meas. Tech., 14, 6675–6693,Short summary
Laser active remote sensing of tropospheric water vapor is a promising technology for enhancing our understanding of processes governing the global hydrological cycle. We investigate the potential of a ground-based lidar to monitor the main water vapor isotopes at high spatio-temporal resolutions in the lower troposphere. Using a realistic end-to-end simulator, we show that high-precision measurements can be achieved within a range of 1.5 km, in mid-latitude or tropical environments.
Qin Wang, Farhan Mustafa, Lingbing Bu, Shouzheng Zhu, Jiqiao Liu, and Weibiao Chen
Atmos. Meas. Tech., 14, 6601–6617,Short summary
In this work, an airborne experiment was carried out to validate a newly developed CO2 monitoring IPDA lidar against the in situ measurements obtained from a commercial CO2 monitoring instrument installed on an aircraft. The XCO2 values calculated with the IPDA lidar measurements were compared with the dry-air CO2 mole fraction measurements obtained from the in situ instruments, and the results showed a good agreement between the two datasets.
Matthias M. Frey, Frank Hase, Thomas Blumenstock, Darko Dubravica, Jochen Groß, Frank Göttsche, Martin Handjaba, Petrus Amadhila, Roland Mushi, Isamu Morino, Kei Shiomi, Mahesh Kumar Sha, Martine de Mazière, and David F. Pollard
Atmos. Meas. Tech., 14, 5887–5911,Short summary
In this study, we present measurements of carbon dioxide, methane and carbon monoxide from a recently established site in Gobabeb, Namibia. Gobabeb is the first site observing these gases on the African mainland and improves the global coverage of measurement sites. Gobabeb is a hyperarid desert site, offering unique characteristics. Measurements started 2015 as part of the COllaborative Carbon Column Observing Network. We compare our results with other datasets and find a good agreement.
René Stübi, Herbert Schill, Jörg Klausen, Eliane Maillard Barras, and Alexander Haefele
Atmos. Meas. Tech., 14, 5757–5769,Short summary
In the first half of the 20th century, Prof. Dobson developed an instrument to measure the ozone column. Around 50 of these Dobson instruments, manufactured in the second half of the 20th century, are still used today to monitor the state of the ozone layer. Started in 1926, the Arosa series was, until recently, based on manually operated Dobsons. To ensure its future operation, a fully automated version of the Dobson has been developed. This well-working automated system is described here.
Timon Hummel, Christian Meister, Corneli Keim, Jasper Krauser, and Mark Wenig
Atmos. Meas. Tech., 14, 5459–5472,Short summary
The impact of heterogeneous scene radiance affects the quality of trace gas retrieval products of Earth observation imaging spectrometers. This effect can be mitigated by introducing on-board hardware solutions called slit homogenizers, which scramble the light entering the instrument and thereby make it insensitive to Earth scene contrast. Here we present a comprehensive modeling of the slit homogenizer present in the Sentinel-5/UVNS instrument and quantify the spectral performance.
Quentin Errera, Emmanuel Dekemper, Noel Baker, Jonas Debosscher, Philippe Demoulin, Nina Mateshvili, Didier Pieroux, Filip Vanhellemont, and Didier Fussen
Atmos. Meas. Tech., 14, 4737–4753,Short summary
ALTIUS is a micro-satellite which will measure the distribution of the ozone layer. Micro-satellites are intended to be cost-effective, but does this make the ALTIUS measurements any less valuable? To answer this, we simulated ALTIUS data and measured how it could constrain a model of the ozone layer; we then compared these results with those obtained from the state-of-the-art NASA Aura MLS satellite ozone measurements. The outcome shows us that the ALTIUS
budgetinstrument is indeed valuable.
Scott M. Spuler, Matthew Hayman, Robert A. Stillwell, Joshua Carnes, Todd Bernatsky, and Kevin S. Repasky
Atmos. Meas. Tech., 14, 4593–4616,Short summary
Continuous water vapor and temperature profiles are critically needed for improved understanding of the lower atmosphere and potential advances in weather forecasting skill. To address this observation need, an active remote sensing technology based on a diode-laser-based lidar architecture is being developed. We discuss the details of the lidar architecture and analyze how it addresses a national-scale profiling network's need to provide continuous thermodynamic observations.
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.
Jia Su, M. Patrick McCormick, Matthew S. Johnson, John T. Sullivan, Michael J. Newchurch, Timothy A. Berkoff, Shi Kuang, and Guillaume P. Gronoff
Atmos. Meas. Tech., 14, 4069–4082,Short summary
A new technique using a three-wavelength differential absorption lidar (DIAL) technique based on an optical parametric oscillator (OPO) laser is proposed to obtain more accurate measurements of NO2. The retrieval uncertainties in aerosol extinction using the three-wavelength DIAL technique are reduced to less than 2 % of those when using the two-wavelength DIAL technique. Hampton University (HU) lidar NO2 profiles are compared with simulated data from the WRF-Chem model, and they agree well.
Carly Staebell, Kang Sun, Jenna Samra, Jonathan Franklin, Christopher Chan Miller, Xiong Liu, Eamon Conway, Kelly Chance, Scott Milligan, and Steven Wofsy
Atmos. Meas. Tech., 14, 3737–3753,Short summary
Given the high global warming potential of CH4, the identification and subsequent reduction of anthropogenic CH4 emissions presents a significant opportunity for climate change mitigation. Satellites are an integral piece of this puzzle, providing data to quantify emissions at a variety of spatial scales. This work presents the spectral calibration of MethaneAIR, the airborne instrument used as a test bed for the forthcoming MethaneSAT satellite.
Marek Šmíd, Geiland Porrovecchio, Jiří Tesař, Tim Burnitt, Luca Egli, Julian Grőbner, Petr Linduška, and Martin Staněk
Atmos. Meas. Tech., 14, 3573–3582,Short summary
We designed and developed a tuneable and portable radiation source (TuPS) to provide a reference wavelength scale, with a bandwidth of emitted radiation of 0.13 nm and uncertainty in wavelength of 0.02 nm. TuPS was successfully used for the in-field characterization of 14 Dobson spectrophotometers in campaigns in Europe. The line spread functions of Dobsons measured by TuPS in conjunction with the cross-sections from IUP improves the consistency between the Dobson and Brewer from 3 % to 1 %.
Nicholas M. Deutscher, Travis A. Naylor, Christopher G. R. Caldow, Hamish L. McDougall, Alex G. Carter, and David W. T. Griffith
Atmos. Meas. Tech., 14, 3119–3130,Short summary
This work describes the performance of an open-path measurement system for greenhouse gases in an extended field trial. The instrument obtained measurement repeatability of 0.1 % or better for CO2 and CH4 measurements over a 1.55 km one-way pathway. Comparison to co-located in situ measurements allows characterisation of biases relative to global reference scales. The research was done to show the applicability of the technique and its ability to detect atmospheric-relevant sources and sinks.
Sebastian Wolff, Gerhard Ehret, Christoph Kiemle, Axel Amediek, Mathieu Quatrevalet, Martin Wirth, and Andreas Fix
Atmos. Meas. Tech., 14, 2717–2736,Short summary
We report on CO2 emissions of a coal-fired power plant derived from flight measurements performed with the IPDA lidar CHARM-F during the CoMet campaign in spring 2018. Despite the results being in broad agreement with reported emissions, we observe strong variations between successive flyovers. Using a high-resolution large eddy simulation, we identify strong atmospheric turbulence as the cause for the variations and recommend more favorable measurement conditions for future campaign planning.
Dylan Jervis, Jason McKeever, Berke O. A. Durak, James J. Sloan, David Gains, Daniel J. Varon, Antoine Ramier, Mathias Strupler, and Ewan Tarrant
Atmos. Meas. Tech., 14, 2127–2140,Short summary
We describe how the GHGSat-D demonstration satellite is designed and operated in order to measure greenhouse gas emissions from different types of industrial facilities. The distinguishing features of GHGSat-D, or
Claire, are its compact size (< 15 kg) and high spatial resolution (< 50 m). We give a mathematical model of the instrument and describe the techniques used to infer a methane concentration from a measurement of the sunlight that has reflected off the Earth's surface.
Hiroshi Suto, Fumie Kataoka, Nobuhiro Kikuchi, Robert O. Knuteson, Andre Butz, Markus Haun, Henry Buijs, Kei Shiomi, Hiroko Imai, and Akihiko Kuze
Atmos. Meas. Tech., 14, 2013–2039,Short summary
The Japanese Greenhouse gases Observing SATellite-2 (GOSAT-2), in orbit since October 2018, is the follow-up mission of GOSAT, which has been operating since January 2009. Both satellites are dedicated to the monitoring of global carbon dioxide and methane to further knowledge of the global carbon cycle. This paper has reported on the function and performance of the TANSO-FTS-2 instrument, level-1 data processing, and calibrations for the first year of GOSAT-2 observation.
Florian Richter, Corneli Keim, Jérôme Caron, Jasper Krauser, Dennis Weise, and Mark Wenig
Atmos. Meas. Tech., 14, 1561–1571,Short summary
Much effort has gone into obtaining crucial information about the progress of climate change, which depends on trace gases in the Earth's atmosphere. Satellite-based imaging spectrometers are used to record the Earth's reflectance in order to quantify the concentration of relevant trace gases. This work contributes an approach to a well-known calibration uncertainty regarding diffuser speckle and could significantly reduce overheads in the future planning phases of such instruments.
Thomas Blumenstock, Frank Hase, Axel Keens, Denis Czurlok, Orfeo Colebatch, Omaira Garcia, David W. T. Griffith, Michel Grutter, James W. Hannigan, Pauli Heikkinen, Pascal Jeseck, Nicholas Jones, Rigel Kivi, Erik Lutsch, Maria Makarova, Hamud K. Imhasin, Johan Mellqvist, Isamu Morino, Tomoo Nagahama, Justus Notholt, Ivan Ortega, Mathias Palm, Uwe Raffalski, Markus Rettinger, John Robinson, Matthias Schneider, Christian Servais, Dan Smale, Wolfgang Stremme, Kimberly Strong, Ralf Sussmann, Yao Té, and Voltaire A. Velazco
Atmos. Meas. Tech., 14, 1239–1252,Short summary
This study investigates the level of channeling (optical resonances) of each FTIR spectrometer within the Network for the Detection of Atmospheric Composition Change (NDACC). Since the air gap of the beam splitter is a significant source of channeling, we propose new beam splitters with an increased wedge of the air gap. This study shows the potential for reducing channeling in the FTIR spectrometers operated by the NDACC, thereby increasing the quality of recorded spectra across the network.
Florian Dietrich, Jia Chen, Benno Voggenreiter, Patrick Aigner, Nico Nachtigall, and Björn Reger
Atmos. Meas. Tech., 14, 1111–1126,Short summary
Climate change is one of the defining issues of our time. However, most of the current emission estimates are based on calculations, not on actual measurements as it is difficult to quantify the emissions of large sources such as cities. This study shows how to use the relatively new approach of column measurements to quantify urban greenhouse gas emissions in an exact way using only a few compact measurement systems. The approach can be used to evaluate the effectiveness of mitigation policies.
Maria V. Makarova, Carlos Alberti, Dmitry V. Ionov, Frank Hase, Stefani C. Foka, Thomas Blumenstock, Thorsten Warneke, Yana A. Virolainen, Vladimir S. Kostsov, Matthias Frey, Anatoly V. Poberovskii, Yuri M. Timofeyev, Nina N. Paramonova, Kristina A. Volkova, Nikita A. Zaitsev, Egor Y. Biryukov, Sergey I. Osipov, Boris K. Makarov, Alexander V. Polyakov, Viktor M. Ivakhov, Hamud Kh. Imhasin, and Eugene F. Mikhailov
Atmos. Meas. Tech., 14, 1047–1073,Short summary
Fundamental understanding of the major processes driving climate change is a key problem which is to be solved, not only on a global but also on a regional scale. The Emission Monitoring Mobile Experiment (EMME) carried out in 2019 with two portable Bruker EM27/SUN spectrometers as core instruments provided new information on the emissions of greenhouse (CO2, CH4) and reactive (CO, NOx) gases from St. Petersburg (Russia), which is the largest northern megacity with a population of 5 million.
Elena Spinei, Martin Tiefengraber, Moritz Müller, Manuel Gebetsberger, Alexander Cede, Luke Valin, James Szykman, Andrew Whitehill, Alexander Kotsakis, Fernando Santos, Nader Abbuhasan, Xiaoyi Zhao, Vitali Fioletov, Sum Chi Lee, and Robert Swap
Atmos. Meas. Tech., 14, 647–663,Short summary
Plastics are widely used in everyday life and scientific equipment. This paper presents Delrin plastic off-gassing as a function of temperature on the atmospheric measurements of formaldehyde by Pandora spectroscopic instruments. The sealed telescope assembly containing Delrin components emitted large amounts of formaldehyde at 30–45 °C, interfering with the Pandora measurements. These results have a broader implication since electronic products often experience the same temperature.
Lisa Klanner, Katharina Höveler, Dina Khordakova, Matthias Perfahl, Christian Rolf, Thomas Trickl, and Hannes Vogelmann
Atmos. Meas. Tech., 14, 531–555,Short summary
The importance of water vapour as the most influential greenhouse gas and for air composition calls for detailed investigations. The details of the highly inhomogeneous distribution of water vapour can be determined with lidar, the very low concentrations at high altitudes imposing a major challenge. An existing water-vapour lidar in the Bavarian Alps was recently complemented by a powerful Raman lidar that provides water vapour up to 20 km and temperature up to 90 km within just 1 h.
Liang Xi, Fuqi Si, Yu Jiang, Haijin Zhou, Kai Zhan, Zhen Chang, Xiaohan Qiu, and Dongshang Yang
Atmos. Meas. Tech., 14, 435–454,Short summary
In this paper, we present a novel airborne imaging differential optical absorption spectroscopy (DOAS) instrument: the Ultraviolet Visible Hyperspectral Imaging Spectrometer (UVHIS), which is developed for trace gas monitoring and pollution mapping. In the first demonstration flight on 23 June 2018, the UVHIS instrument clearly detected several NO2 emission plumes transporting from south to north. UVHIS NO2 vertical columns are well correlated with ground-based mobile DOAS observations.
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.
Thomas Trickl, Helmuth Giehl, Frank Neidl, Matthias Perfahl, and Hannes Vogelmann
Atmos. Meas. Tech., 13, 6357–6390,Short summary
Lidar sounding of ozone and other atmospheric constituents has proved to be an invaluable tool for atmospheric studies. The ozone lidar systems developed at Garmisch-Partenkirchen have reached an accuracy level almost matching that of in situ sensors. Since the late 1990s numerous important scientific discoveries have been made, such as the first observation of intercontinental transport of ozone and the very high occurrence of intrusions of stratospheric air into the troposphere.
John Robinson, Dan Smale, David Pollard, and Hisako Shiona
Atmos. Meas. Tech., 13, 5855–5871,Short summary
Solar trackers are used by spectrometers to measure atmospheric trace gas concentrations using direct-sun spectroscopy. The ideal tracker should be sufficiently accurate, highly reliable, and with a longevity that exceeds the lifetime of the spectrometer which it serves. It should also be affordable, easy to use, and not too complex should maintenance be required. We present a design that fulfils these requirements using some simple innovations.
Luis Millán, Richard Roy, and Matthew Lebsock
Atmos. Meas. Tech., 13, 5193–5205,Short summary
This paper describes the feasibility of using a differential absorption radar technique for the remote sensing of total column water vapor from a spaceborne platform.
Mahesh Kumar Sha, Martine De Mazière, Justus Notholt, Thomas Blumenstock, Huilin Chen, Angelika Dehn, David W. T. Griffith, Frank Hase, Pauli Heikkinen, Christian Hermans, Alex Hoffmann, Marko Huebner, Nicholas Jones, Rigel Kivi, Bavo Langerock, Christof Petri, Francis Scolas, Qiansi Tu, and Damien Weidmann
Atmos. Meas. Tech., 13, 4791–4839,Short summary
We present the results of the 2017 FRM4GHG campaign at the Sodankylä TCCON site aimed at characterising the assessment of several low-cost portable instruments for precise solar absorption measurements of column-averaged dry-air mole fractions of CO2, CH4, and CO. The test instruments provided stable and precise measurements of these gases with quantified small biases. This qualifies the instruments to complement TCCON and expand the global coverage of ground-based measurements of these gases.
Zoë Y. W. Davis and Robert McLaren
Atmos. Meas. Tech., 13, 3993–4008,Short summary
MAX-DOAS is a technique that can be used to measure pollutant concentrations and vertical profiles in the atmosphere via remote sensing of sky-scattered light with a telescope. Measuring SO2 is particularly challenging because of low light intensities in regions where SO2 absorbs solar radiation. Here, we performed experiments that document inaccuracies in these measurements as a function of spectral
fitting windows. We provide recommendations for measuring SO2 with greater accuracy.
Benoît Tournadre, Pascale Chelin, Mokhtar Ray, Juan Cuesta, Rebecca D. Kutzner, Xavier Landsheere, Audrey Fortems-Cheiney, Jean-Marie Flaud, Frank Hase, Thomas Blumenstock, Johannes Orphal, Camille Viatte, and Claude Camy-Peyret
Atmos. Meas. Tech., 13, 3923–3937,Short summary
We present some results about ammonia pollution because NH3, mainly emitted by agricultural activities, is a precursor of fine particles. This study is based on the first multiyear time series (2009–2017) of atmospheric NH3 ground-based measurements over the Paris megacity. This pollutant varies seasonally by 2 orders of magnitude, especially in spring. We highlight that this kind of instrument could be easily installed and is very useful for analyzing NH3 in other megacities or source regions.
Amediek, A., Fix, A., Ehret, G., Caron, J., and Durand, Y.: Airborne lidar reflectance measurements at 1.57 μm in support of the A-SCOPE mission for atmospheric CO2, Atmos. Meas. Tech., 2, 755–772, https://doi.org/10.5194/amt-2-755-2009, 2009.
Bréon, F. M., Aben, I., Boesch, H., Bormann, N., Bruneau, D., Chevallier, F., Ehret, G., Engelen, R., Flamant, P., Gerbig, C., Heimann, M., Houweling, S., Lezeaux, F. O., Peylin, P., Prunet, P., Rayner, P., Rödenbeck, C., and Thepaut, J. N.: Observation Techniques and Mission Concepts for Analysis of the Global Carbon Cycle, Final Report, ESA Study, Contract No. 20839/07/NL/HE, 2008.
Bruneau, D., Gibert, F., Flamant, P. H., and Pelon, J.: Complementary study of differential absorption lidar optimization in direct and heterodyne detections, Appl. Optics, 45, 4898–4908, 2006.
Caron, J. and Durand, Y.: Operating wavelengths optimization for a spaceborne lidar measuring atmospheric CO2, Appl. Optics, 48, 5413–5422, 2009.
Davy, B., Pecher, I., Wood, R., Carter, L., and Gohl, K.: Gas escape features off New Zealand: Evidence of massive release of methane from hydrates, Geophys. Res. Lett., 37, L21309, https://doi.org/10.1029/2010GL045184, 2010.
Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P., Kobayashi, S., Andrae, U., Balmaseda, M. A., Balsamo, G., Bauer, P., Bechtold, P., Beljaars, A. C. M., van de Berg, L., Bidlot, J., Bormann, N., Delsol, C., Dragani, R., Fuentes, M., Geer, A. J., Haimberger, L., Healy, S. B., Hersbach, H., Holm, E. V., Isaksen, L., Kallberg, P., Koehler, M., Matricardi, M., McNally, A. P., Monge-Sanz, B. M., Morcrette, J.-J., Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C., Thepaut, J.-N., and Vitart, F.: The ERA-Interim reanalysis: configuration and performance of the data assimilation system, Q. J. Roy. Meteorol. Soc., 137, 553–597, https://doi.org/10.1002/qj.828, 2011.
Dufour, E. and Bréon, F.-M.: Spaceborne estimate of atmospheric CO2 column by use of the differential absorption method: error analysis, Appl. Optics, 42, 3595–3609, 2003.
Ehret, G. and Kiemle, C.: Requirements Definition for Future DIAL Instruments, Final Report, ESA Study CR(P)-4513, Contract 10880/03/NL/FF, 2005.
Ehret, G., Kiemle, C., Wirth, M., Amediek, A., Fix, A., and Houweling, S.: Space-borne remote sensing of CO2, CH4, and N2O by integrated path differential absorption lidar: a sensitivity analysis, Appl. Phys. B, 90, 593–608, https://doi.org/10.1007/s00340-007-2892-3, 2008.
Ehret, G., Flamant, P., Amediek, A., Ciais, P., Gibert, F., Fix, A., Kiemle, C., Quatrevalet, M., and Wirth, M.: The French-German Climate Monitoring Initiative on Global Observations of Atmospheric Methane, Proc. 25th Int. Laser Radar Conf., St. Petersburg, Russia, July 2010.
Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D. W., Haywood, J., Lean, J., Lowe, D. C., Myhre, G., Nganga, J., Prinn, R., Raga, G., Schulz, M., and Van Dorland, R.: Changes in Atmospheric Constituents and in Radiative Forcing, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, UK and New York, NY, USA, 2007.
Frankenberg, C., Warneke, T., Butz, A., Aben, I., Hase, F., Spietz, P., and Brown, L. R.: Pressure broadening in the 2 \nu3 band of methane and its implication on atmospheric retrievals, Atmos. Chem. Phys., 8, 5061–5075, https://doi.org/10.5194/acp-8-5061-2008, 2008.
Gerbig, C., Dolman, A. J., and Heimann, M.: On observational and modelling strategies targeted at regional carbon exchange over continents, Biogeosciences, 6, 1949–1959, https://doi.org/10.5194/bg-6-1949-2009, 2009.
Heimann, M.: How Stable Is the Methane Cycle?, Science, 327, 1211–1212, 2010.
Hungershoefer, K., Breon, F.-M., Peylin, P., Chevallier, F., Rayner, P., Klonecki, A., Houweling, S., and Marshall, J.: Evaluation of various observing systems for the global monitoring of CO2 surface fluxes, Atmos. Chem. Phys., 10, 10503–10520, https://doi.org/10.5194/acp-10-10503-2010, 2010.
Ingmann, P., Bensi, P., and Durand, Y.: Candidate Earth Explorer Core Missions – Reports for Assessment: A-SCOPE – Advanced Space Carbon and climate Observation of Planet Earth, ESA SP-1313/1, ISBN 978-92-9221-406-7, ISSN 0379-6566, 2008.
Ismail, S. and Browell, E. V.: Airborne and spaceborne lidar measurements of water vapor profiles: a sensitivity analysis, Appl. Opticsc, 28, 3603–3614, 1989.
Kaminski, T., Scholze, M., and Houweling, S.: Quantifying the benefit of A-SCOPE data for reducing uncertainties in terrestrial carbon fluxes in CCDAS, Tellus B, 62, 784–796, https://doi.org/10.1111/j.1600-0889.2010.00483.x, 2010.
Kawa, S. R., Mao, J., Abshire, J. B., Collatz, G. J., Sun, X., Weaver, C. J.: Simulation studies for a space-based CO2 lidar mission, Tellus B, 62, 759–769, https://doi.org/10.1111/j.1600-0889.2010.00486.x, 2010.
Mayer, B. and Kylling, A.: Technical note: The libRadtran software package for radiative transfer calculations – description and examples of use, Atmos. Chem. Phys., 5, 1855–1877, https://doi.org/10.5194/acp-5-1855-2005, 2005.
Menzies, R. T., Tratt, D. M., Spinhirne, J. D., and Hlavka, D. L.: Aerosol layers over the Pacific Ocean: Vertical distributions and optical properties as observed by multiwavelength airborne lidars, J. Geophys. Res., 107, 4292, https://doi.org/10.1029/2001JD001196, 2002.
Milkov, A. V.: Global estimates of hydrate-bound gas in marine sediments: How much is really out there?, Earth Sci. Rev. 66, 183–197, https://doi.org/10.1016/j.earscirev.2003.11.002, 2004.
Morino, I., Uchino, O., Inoue, M., Yoshida, Y., Yokota, T., Wennberg, P. O., Toon, G. C., Wunch, D., Roehl, C. M., Notholt, J., Warneke, T., Messerschmidt, J., Griffith, D. W. T., Deutscher, N. M., Sherlock, V., Connor, B., Robinson, J., Sussmann, R., and Rettinger, M.: Preliminary validation of column-averaged volume mixing ratios of carbon dioxide and methane retrieved from GOSAT short-wavelength infrared spectra, Atmos. Meas. Tech., 4, 1061–1076, https://doi.org/10.5194/amt-4-1061-2011, 2011.
Petersen, A. K., Warneke, T., Frankenberg, C., Bergamaschi, P., Gerbig, C., Notholt, J., Buchwitz, M., Schneising, O., and Schrems, O.: First ground-based FTIR observations of methane in the inner tropics over several years, Atmos. Chem. Phys., 10, 7231–7239, https://doi.org/10.5194/acp-10-7231-2010, 2010.
Rothman, L. S., Gordon, I. E., Barbe, A., Benner, D. C., Bernath, P. F., Birk, M., Boudon, V., Brown, L. R., Campargue, A., Champion, J.-P., Chance, K., Coudert, L. H., Dana, V., Devi, V. M., Fally, S., Flaud, J.-M., Gamache, R. R., Goldman, A., Jacquemart, D., Kleiner, I., Lacome, N., Lafferty, W. J., Mandin, J.-Y., Massie, S. T., Mikhailenko, S. N., Miller, C. E., Moazzen-Ahmadi, N., Naumenko, O., Nikitin, A. V., Orphal, J., Perevalov, V. I., Perrin, A., Predoi-Cross, A., Rinsland, C. P., Rotger, M., Simecková, M., Smith, M. A. H., Sung, K., Tashkun, S. A., Tennyson, J., Toth, R. A., Vandaele, A. C., and Vander Auwera, J.: The HITRAN 2008 molecular spectroscopic database, J. Quant. Spectrosc. Ra., 110, 533–572, https://doi.org/10.1016/j.jqsrt.2009.02.013, 2009.
Schneising, O., Buchwitz, M., Reuter, M., Heymann, J., Bovensmann, H., and Burrows, J. P.: Long-term analysis of carbon dioxide and methane column-averaged mole fractions retrieved from SCIAMACHY, Atmos. Chem. Phys., 11, 2863–2880, https://doi.org/10.5194/acp-11-2863-2011, 2011.
Vaughan, J. M., Brown, D. W., Nash, C., Alejandro, S. B., and Koenig, G. G.: Atlantic atmospheric aerosols studies 2. Compendium of airborne backscatter measurements at 10.6 μm, J. Geophys. Res., 100, 1043–1065, 1995.
Villani, M. G., Bergamaschi, P., Krol, M., Meirink, J. F., and Dentener, F.: Inverse modeling of European CH4 emissions: sensitivity to the observational network, Atmos. Chem. Phys., 10, 1249–1267, https://doi.org/10.5194/acp-10-1249-2010, 2010.