Retrieval of greenhouse gases from GOSAT and GOSAT-2 using the FOCAL algorithm

S. Noël; M. Reuter; M. Buchwitz; J. Borchardt; M. Hilker; O. Schneising; H. Bovensmann; J. P. Burrows; A. Di Noia; R. J. Parker; R. J. Parker; H. Suto; Y. Yoshida; M. Buschmann; N. M. Deutscher; D. G. Feist; D. G. Feist; D. G. Feist; D. W. T. Griffith; F. Hase; R. Kivi; C. Liu; I. Morino; J. Notholt; Y.-S. Oh; H. Ohyama; C. Petri; D. F. Pollard; M. Rettinger; C. Roehl; C. Rousogenous; M. K. Sha; K. Shiomi; K. Strong; R. Sussmann; Y. Té; V. A. Velazco; V. A. Velazco; M. Vrekoussis; M. Vrekoussis; M. Vrekoussis; T. Warneke

doi:10.5194/amt-15-3401-2022

Atmospheric Measurement Techniques (Jun 2022)

Retrieval of greenhouse gases from GOSAT and GOSAT-2 using the FOCAL algorithm

S. Noël,
M. Reuter,
M. Buchwitz,
J. Borchardt,
M. Hilker,
O. Schneising,
H. Bovensmann,
J. P. Burrows,
A. Di Noia,
R. J. Parker,
R. J. Parker,
H. Suto,
Y. Yoshida,
M. Buschmann,
N. M. Deutscher,
D. G. Feist,
D. G. Feist,
D. G. Feist,
D. W. T. Griffith,
F. Hase,
R. Kivi,
C. Liu,
I. Morino,
J. Notholt,
Y.-S. Oh,
H. Ohyama,
C. Petri,
D. F. Pollard,
M. Rettinger,
C. Roehl,
C. Rousogenous,
M. K. Sha,
K. Shiomi,
K. Strong,
R. Sussmann,
Y. Té,
V. A. Velazco,
V. A. Velazco,
M. Vrekoussis,
M. Vrekoussis,
M. Vrekoussis,
T. Warneke

Affiliations

S. Noël: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
M. Reuter: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
M. Buchwitz: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
J. Borchardt: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
M. Hilker: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
O. Schneising: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
H. Bovensmann: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
J. P. Burrows: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
A. Di Noia: Earth Observation Science, University of Leicester, LE1 7RH, Leicester, UK
R. J. Parker: Earth Observation Science, University of Leicester, LE1 7RH, Leicester, UK
R. J. Parker: National Centre for Earth Observation, University of Leicester, Leicester, UK
H. Suto: Japan Aerospace Exploration Agency (JAXA), 305-8505, Tsukuba, Japan
Y. Yoshida: National Institute for Environmental Studies (NIES), Onogawa 16-2, Tsukuba, Ibaraki 305-8506, Japan
M. Buschmann: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
N. M. Deutscher: Centre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW 2522, Wollongong, Australia
D. G. Feist: Max Planck Institute for Biogeochemistry, 07745 Jena, Germany
D. G. Feist: Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, 82234 Oberpfaffenhofen, Germany
D. G. Feist: Ludwig-Maximilians-Universität München, Lehrstuhl für Physik der Atmosphäre, 80539 Munich, Germany
D. W. T. Griffith: Centre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW 2522, Wollongong, Australia
F. Hase: Karlsruhe Institute of Technology, IMK-ASF, 76021 Karlsruhe, Germany
R. Kivi: Finnish Meteorological Institute, Space and Earth Observation Centre, Tähteläntie 62, 99600 Sodankylä, Finland
C. Liu: Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, 230026 Hefei, China
I. Morino: National Institute for Environmental Studies (NIES), Onogawa 16-2, Tsukuba, Ibaraki 305-8506, Japan
J. Notholt: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
Y.-S. Oh: Global Atmosphere Watch Team, Innovative Meteorological Research Department, National Institute of Meteorological Sciences, 3 Seohobuk-ro, Seogwipo-si, Jeju-do, Republic of Korea
H. Ohyama: National Institute for Environmental Studies (NIES), Onogawa 16-2, Tsukuba, Ibaraki 305-8506, Japan
C. Petri: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
D. F. Pollard: National Institute of Water and Atmospheric Research Ltd (NIWA), Lauder, Private Bag 50061, Omakau 9352, New Zealand
M. Rettinger: Karlsruhe Institute of Technology, IMK-IFU, 82467 Garmisch-Partenkirchen, Germany
C. Roehl: California Institute of Technology, Global Environmental Center, Pasadena, CA 91125, USA
C. Rousogenous: Climate and Atmosphere Research Center (CARE-C), The Cyprus Institute, Nicosia, Cyprus
M. K. Sha: Royal Belgian Institute for Space Aeronomy (BIRA-IASB), 1180 Brussels, Belgium
K. Shiomi: Japan Aerospace Exploration Agency (JAXA), 305-8505, Tsukuba, Japan
K. Strong: Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
R. Sussmann: Karlsruhe Institute of Technology, IMK-IFU, 82467 Garmisch-Partenkirchen, Germany
Y. Té: Laboratoire d'Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA-IPSL), Sorbonne Université, CNRS, Observatoire de Paris, PSL Université, 75005 Paris, France
V. A. Velazco: Centre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW 2522, Wollongong, Australia
V. A. Velazco: Deutscher Wetterdienst, Meteorological Observatory, 82383 Hohenpeissenberg, Germany
M. Vrekoussis: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany
M. Vrekoussis: Climate and Atmosphere Research Center (CARE-C), The Cyprus Institute, Nicosia, Cyprus
M. Vrekoussis: Center of Marine Environmental Sciences (MARUM), University of Bremen, Bremen, Germany
T. Warneke: Institute of Environmental Physics, University of Bremen, FB 1, P.O. Box 330440, 28334 Bremen, Germany

DOI: https://doi.org/10.5194/amt-15-3401-2022
Journal volume & issue: Vol. 15
pp. 3401 – 3437

Abstract

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We show new results from an updated version of the Fast atmOspheric traCe gAs retrievaL (FOCAL) retrieval method applied to measurements of the Greenhouse gases Observing SATellite (GOSAT) and its successor GOSAT-2. FOCAL was originally developed for estimating the total column carbon dioxide mixing ratio (XCO2) from spectral measurements made by the Orbiting Carbon Observatory-2 (OCO-2). However, depending on the available spectral windows, FOCAL also successfully retrieves total column amounts for other atmospheric species and their uncertainties within one single retrieval. The main focus of the current paper is on methane (XCH4; full-physics and proxy product), water vapour (XH2O) and the relative ratio of semi-heavy water (HDO) to water vapour (δD). Due to the extended spectral range of GOSAT-2, it is also possible to derive information on carbon monoxide (XCO) and nitrous oxide (XN2O) for which we also show first results. We also present an update on XCO2 from both instruments. For XCO2, the new FOCAL retrieval (v3.0) significantly increases the number of valid data compared with the previous FOCAL retrieval version (v1) by 50 % for GOSAT and about a factor of 2 for GOSAT-2 due to relaxed pre-screening and improved post-processing. All v3.0 FOCAL data products show reasonable spatial distribution and temporal variations. Comparisons with the Total Carbon Column Observing Network (TCCON) result in station-to-station biases which are generally in line with the reported TCCON uncertainties. With this updated version of the GOSAT-2 FOCAL data, we provide a first total column average XN2O product. Global XN2O maps show a gradient from the tropics to higher latitudes on the order of 15 ppb, which can be explained by variations in tropopause height. The new GOSAT-2 XN2O product compares well with TCCON. Its station-to-station variability is lower than 2 ppb, which is about the magnitude of the typical N2O variations close to the surface. However, both GOSAT-2 and TCCON measurements show that the seasonal variations in the total column average XN2O are on the order of 8 ppb peak-to-peak, which can be easily resolved by the GOSAT-2 FOCAL data. Noting that only few XN2O measurements from satellites exist so far, the GOSAT-2 FOCAL product will be a valuable contribution in this context.

Published in Atmospheric Measurement Techniques

ISSN: 1867-1381 (Print); 1867-8548 (Online)
Publisher: Copernicus Publications
Country of publisher: Germany
LCC subjects: Technology: Engineering (General). Civil engineering (General): Environmental engineering; Technology: Engineering (General). Civil engineering (General): Earthwork. Foundations
Website: http://www.atmospheric-measurement-techniques.net/home.html

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