Carbon dioxide variations in the upper troposphere and lower stratosphere from GOSAT TANSO-FTS TIR profile data

Abstract

Abstract. Carbon dioxide (CO2) variations in the upper troposphere and lower stratosphere (UT and LS; pressure = 300–70 hPa) were investigated with profile data derived from the thermal infrared region (Band 4: 5.5–14.3 μm) of the Thermal And Near-infrared Sensor for carbon Observation (TANSO)–Fourier Transform Spectrometer (FTS) onboard the Greenhouse gas Observing SATellite (GOSAT). The vertical profile data (Level 2; version 1) of CO2 mixing ratios were obtained by bias correction using the in situ aircraft data. Data with sufficient sensitivity were used for the analysis by selecting values with higher degrees of freedom. The analysis period is over four years from January 2010 to December 2013. The increase of CO2 mixing ratios obtained with the bias correction in the UT and LS was 1.8–2.4 ppmv year−1 from 2010–2013, which is consistent with a previous observational study and almost the same as for the lower troposphere (LT). The seasonal variations in the UT and LS show that a maximum peak exists one or two months after the peak in the LT, and has an amplitude of 4–5 ppmv, which is less than that in the LT. The inter-annual variations observed in the tropical UT appear to be affected by ENSO events; higher (lower) CO2 mixing ratios were observed during La Niña (normal/El Niño) periods. Intra-seasonal variations over the Asian summer monsoon region were associated with both vertical and horizontal motions owing to deep convection and monsoonal anticyclonic circulation, respectively.

Reconstructing global daily XCO2 at 1° × 1° spatial resolution from 2016 to 2019 with multisource satellite observation data

“…GOSAT is the first artificial satellite that measures greenhouse gases all the time. Thermal and near-infrared sensor for carbon observation, which consists of Fourier transform spectrometer and a cloud and aerosol imager, is an observation instrument on the satellite 30 . There are mainly two CO2 inversion products covering the globe from the GOSAT satellite, one is the GOSAT-NIES product released by the Japanese National Institute for Environmental Studies (NIES) team, and the other is the GOSAT-ACOS product released by the American ACOS team.…”

“…Thermal and near-infrared sensor for carbon observation, which consists of Fourier transform spectrometer and a cloud and aerosol imager, is an observation instrument on the satellite. 30 There are mainly two CO 2 inversion products covering the globe from the GOSAT satellite, one is the GOSAT-NIES product released by the Japanese National Institute for Environmental Studies (NIES) team, and the other is the GOSAT-ACOS product released by the American ACOS team. This paper mainly uses the 9r lite version of the GOSAT product released by the American ACOS team, which has several advantages over the GOSAT-NIES product in academic research.…”