Comment on amt-2021-31
Abstract
Abstract. The thermal infrared nadir spectra of IASI (Infrared Atmospheric Sounding Interferometer) are successfully used for retrievals of different atmospheric trace gas profiles. However, these retrievals offer generally reduced information about the lowermost tropospheric layer due to the lack of thermal contrast close to the surface. Spectra of scattered solar radiation observed in the near-infrared and/or shortwave infrared, for instance by TROPOMI (TROPOspheric Monitoring Instrument), offer higher sensitivity near the ground and are used for the retrieval of total-column-averaged mixing ratios of a variety of atmospheric trace gases. Here we present a method for the synergetic use of IASI profile and TROPOMI total-column level 2 retrieval products. Our method uses the output of the individual retrievals and consists of linear algebra a posteriori calculations (i.e. calculation after the individual retrievals). We show that this approach has strong theoretical similarities to applying the spectra of the different sensors together in a single retrieval procedure but with the substantial advantage of being applicable to data generated with different individual retrieval processors, of being very time efficient, and of directly benefiting from the high quality and most recent improvements of the individual retrieval processors. We demonstrate the method exemplarily for atmospheric methane (CH4). We perform a theoretical evaluation and show that the a posteriori combination method yields a total-column-averaged CH4 product (XCH4) that conserves the good sensitivity of the corresponding TROPOMI product while merging it with the high-quality upper troposphere–lower stratosphere (UTLS) CH4 partial-column information of the corresponding IASI product. As a consequence, the combined product offers additional sensitivity for the tropospheric CH4 partial column, which is not provided by the individual TROPOMI nor the individual IASI product. The theoretically predicted synergetic effect is verified by comparisons to CH4 reference data obtained from collocated XCH4 measurements at 14 globally distributed TCCON (Total Carbon Column Observing Network) stations, CH4 profile measurements made by 36 individual AirCore soundings, and tropospheric CH4 data derived from continuous ground-based in situ observations made at two nearby Global Atmospheric Watch (GAW) mountain stations. The comparisons clearly demonstrate that the combined product can reliably detect the actual variations of atmospheric XCH4, CH4 in the UTLS, and CH4 in the troposphere. A similar good reliability for the latter is not achievable by the individual TROPOMI and IASI products.
Authors 34
-
Matthias F. Schneider corresponding
Karlsruhe Institute of Technology · University of Bern · Oeschger Centre for Climate Change Research · Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Laboratoire des Sciences du Climat et de l'Environnement · CEA Paris-Saclay
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA, 91191 Gif-sur-Yvette, France
now at: Laboratory for the Analysis of Radiocarbon with AMS (LARA), Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP) & Oeschger Centre for Climate Change Research (OCCR), University of Bern, Bern, Switzerland
-
Karlsruhe Institute of Technology
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
Steinbuch Centre for Computing (SCC), Karlsruhe Institute of Technology, Karlsruhe, Germany
-
Karlsruhe Institute of Technology · Tongji University
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
now at: School of Mechanical Engineering, Tongji University, Shanghai, China
-
Karlsruhe Institute of Technology
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
now at: Software Solutions Department, Telespazio Germany GmbH, Darmstadt, Germany
-
Karlsruhe Institute of Technology
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
-
Karlsruhe Institute of Technology
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
-
Karlsruhe Institute of Technology
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
-
Karlsruhe Institute of Technology
Affiliation as printed
Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology, Karlsruhe, Germany
-
Agencia Estatal de Meteorología
Affiliation as printed
Izaña Atmospheric Research Center, Agencia Estatal de Meteorología (AEMET), Santa Cruz de Tenerife, Spain
-
Agencia Estatal de Meteorología
Affiliation as printed
Izaña Atmospheric Research Center, Agencia Estatal de Meteorología (AEMET), Santa Cruz de Tenerife, Spain
-
Space Research Organisation Netherlands
Affiliation as printed
Earth Science Group, SRON Netherlands Institute for Space Research, Utrecht, the Netherlands
-
Space Research Organisation Netherlands
Affiliation as printed
Earth Science Group, SRON Netherlands Institute for Space Research, Utrecht, the Netherlands
-
Space Research Organisation Netherlands
Affiliation as printed
Earth Science Group, SRON Netherlands Institute for Space Research, Utrecht, the Netherlands
-
Affiliation as printed
Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany
-
Affiliation as printed
Center for Isotope Research, University of Groningen, Groningen, the Netherlands
-
Finnish Meteorological Institute
Affiliation as printed
Space and Earth Observation Centre, Finnish Meteorological Institute, Sodankylä, Finland
-
University of Bern · Oeschger Centre for Climate Change Research · Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Laboratoire des Sciences du Climat et de l'Environnement · CEA Paris-Saclay
Affiliation as printed
Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA, 91191 Gif-sur-Yvette, France
now at: Laboratory for the Analysis of Radiocarbon with AMS (LARA), Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP) & Oeschger Centre for Climate Change Research (OCCR), University of Bern, Bern, Switzerland
-
Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Laboratoire des Sciences du Climat et de l'Environnement · CEA Paris-Saclay
Affiliation as printed
Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA, 91191 Gif-sur-Yvette, France
-
Centre National de la Recherche Scientifique · École Polytechnique
Affiliation as printed
LMD/IPSL, CNRS, École polytechnique, University Paris-Saclay, Palaiseau, France
-
Centre National de la Recherche Scientifique · École Polytechnique
Affiliation as printed
LMD/IPSL, CNRS, École polytechnique, University Paris-Saclay, Palaiseau, France
-
Swiss Federal Laboratories for Materials Science and Technology
Affiliation as printed
Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
-
Affiliation as printed
Air Monitoring Network, Federal Environment Agency (UBA), Langen, Germany
-
Affiliation as printed
Department of Physics, Universtity of Toronto, Toronto, Canada
-
Affiliation as printed
Department of Physics, Universtity of Toronto, Toronto, Canada
-
Affiliation as printed
Institute of Environmental Physics, University of Bremen, Bremen, Germany
-
California Institute of Technology
Affiliation as printed
Geological and Planetary Science Division, California Institute of Technology, Pasadena, CA, USA
-
California Institute of Technology
Affiliation as printed
Geological and Planetary Science Division, California Institute of Technology, Pasadena, CA, USA
-
National Institute for Environmental Studies
Affiliation as printed
Satellite Observation Center, National Institute for Environmental Studies (NIES), Tsukuba, Ibaraki, Japan
-
Affiliation as printed
Atmospheric Science Branch, NASA Ames Research Center, Moffett Field, CA, USA
-
Japan Aerospace Exploration Agency
Affiliation as printed
Earth Observation Research Center (EORC), Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
-
Affiliation as printed
Centre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia
-
Affiliation as printed
Centre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia
-
Deutscher Wetterdienst · University of Wollongong
Affiliation as printed
Centre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia
now at: Meteorological Observatory Hohenpeissenberg, Deutscher Wetterdienst (DWD), Albin-Schwaiger-Weg 10, 82383 Hohenpeissenberg, Germany
-
National Institute of Water and Atmospheric Research
Affiliation as printed
National Institute of Water and Atmospheric Research Ltd (NIWA), Lauder, New Zealand
Cited by 0 stored of 0
No patents citing this paper on Lens.org (checked 2026-10-11).