1Key Laboratory of Middle Atmosphere and Global Environment Observation,
Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing,
2Belgian Institute for Space Aeronomy, Brussels, Belgium
3University of Chinese Academy of Sciences, Beijing, China
4SRON Netherlands Institute for Space Research, Utrecht, the Netherlands
5National Institute for Environmental Studies, Tsukuba, Japan
6Colorado State University, Fort Collins, CO, USA
7Max Planck Institute for Biogeochemistry, Jena, Germany
8Centre for Atmospheric Chemistry, University of Wollongong, Wollongong,
9Institute of Meteorology and Climate Research (IMK-ASF), Karlsruhe
Institute of Technology, Karlsruhe, Germany
Received: 25 Sep 2015 – Discussion started: 26 Oct 2015
Abstract. The thermal And near infrared sensor for carbon observations Fourier transform spectrometer (TANSO-FTS) on board the Greenhouse Gases Observing Satellite (GOSAT) applies the normal nadir mode above the land (“land data”) and sun glint mode over the ocean (“ocean data”) to provide global distributions of column-averaged dry-air mole fractions of CO2 and CH4, or XCO2 and XCH4. Several algorithms have been developed to obtain highly accurate greenhouse gas concentrations from TANSO-FTS/GOSAT spectra. So far, all the retrieval algorithms have been validated with the measurements from ground-based Fourier transform spectrometers from the Total Carbon Column Observing Network (TCCON), but limited to the land data. In this paper, the ocean data of the SRPR, SRFP (the proxy and full-physics versions 2.3.5 of SRON/KIT's RemoTeC algorithm), NIES (National Institute for Environmental Studies operational algorithm version 02.21) and ACOS (NASA's Atmospheric CO2 Observations from Space version 3.5) are compared with FTIR measurements from five TCCON sites and nearby GOSAT land data.For XCO2, both land and ocean data of NIES, SRFP and ACOS show good agreement with TCCON measurements. Averaged over all TCCON sites, the relative biases of ocean data and land data are −0.33 and −0.13 % for NIES, 0.03 and 0.04 % for SRFP, 0.06 and −0.03 % for ACOS, respectively. The relative scatter ranges between 0.31 and 0.49 %. For XCH4, the relative bias of ocean data is even less than that of the land data for the NIES (0.02 vs. −0.35 %), SRFP (0.04 vs. 0.20 %) and SRPR (−0.02 vs. 0.06 %) algorithms. Compared to the results for XCO2, the XCH4 retrievals show larger relative scatter (0.65–0.81 %).
Revised: 26 Feb 2016 – Accepted: 18 Mar 2016 – Published: 01 Apr 2016
Zhou, M., Dils, B., Wang, P., Detmers, R., Yoshida, Y., O'Dell, C. W., Feist, D. G., Velazco, V. A., Schneider, M., and De Mazière, M.: Validation of TANSO-FTS/GOSAT XCO2 and XCH4 glint mode retrievals using TCCON data from near-ocean sites, Atmos. Meas. Tech., 9, 1415-1430, doi:10.5194/amt-9-1415-2016, 2016.