Retrievals of Total and Tropospheric Ozone From GOSAT Thermal Infrared Spectral Radiances

Abstract

Total and tropospheric ozone columns have been retrieved from thermal infrared spectral radiances recorded with the Thermal And Near infrared Sensor for carbon ObservationFourier Transform Spectrometer (TANSO-FTS), which is onboard the Greenhouse gases Observing SATellite launched on January 23, 2009. We present ozone retrievals that were performed over about two years of observations (during the period from April 2009 to December 2010) over four climatically distinct regions (the Sapporo, Tsukuba, Naha, and Syowa sites). Annual variations of the total and tropospheric ozone columns over the four sites were derived. We compare TANSO-FTS total ozone columns with ground-based data from the Dobson spectrophotometer, and the seasonal trends and patterns of the retrieved total ozone are consistent with those of Dobson measurements. The TANSO-FTS total ozone columns are in good agreement with the Dobson data, with a correlation coefficient of about 0.98. On average, TANSO-FTS total ozone retrievals exhibit a positive bias of 8.8 DU (3.0%) with a root-mean-square difference of 10.9 DU (4.1%) compared to the Dobson measurements. Comparisons of the TANSO-FTS tropospheric ozone columns to ozonesondes available from the four sites have been performed. The TANSO-FTS tropospheric ozone columns compare well with the ozonesonde measurements, with correlation coefficients of 0.96 and 0.92 for the surface-tropopause and surface-6 km partial columns, respectively. Average differences of 0.7 ± 4.2 DU (2.5% ± 12.8%) and −0.7 ± 2.2 DU(−3.0% ± 12.2%) are found for the surface-tropopause and surface-6 km partial columns, respectively.

Intercomparison of XH2O Data from the GOSAT TANSO-FTS (TIR and SWIR) and Ground-Based FTS Measurements: Impact of the Spatial Variability of XH2O on the Intercomparison

“…The analytical error estimations for the TIR and SWIR products are described by Ohyama et al [61] and Yoshida et al [38], respectively. Smoothing errors were considered in Equations (6)- (8).…”

Algorithm update of the GOSAT/TANSO-FTS thermal infrared CO<sub>2</sub> product (version 1) and validation of the UTLS CO<sub>2</sub> data using CONTRAIL measurements

“…TANSO-FTS consists of three bands in the SWIR region and one band in the TIR region. Column amounts of greenhouse gases are observed in the SWIR bands, and vertical information of gas concentrations are obtained in the TIR band (Yoshida et al, 2011Saitoh et al, 2009Saitoh et al, , 2012Ohyama et al, 2012Ohyama et al, , 2013. Kuze et al (2012) provided a detailed description of the methods used for the processing and calibration of level 1B (L1B) spectral data from TANSO-FTS.…”

DIAL measurement of lower tropospheric ozone over Saga (33.24° N, 130.29° E), Japan, and comparison with a chemistry–climate model

“…In 2011, we deployed an ozone DIfferential Absorption Lidar (ozone DIAL) system, originally developed by the National Institute for Environmental Studies (NIES) at Tsukuba, at Saga (33.24 • N, 130.29 • E) in the Kyushu district, with three aims: (1) to validate GOSAT (Greenhouse gases Observing SATellite) ozone products retrieved from thermal infrared spectral radiances by the Thermal And Near infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard GOSAT (Ohyama et al, 2012); (2) to detect high-ozone concentrations in the lower troposphere; and (3) to compare the observed concentrations with concentration data predicted by the Meteorological Research Institute's (MRI) chemistry-climate model, version 2 (MRI-CCM2) (Deushi and Shibata, 2011). Except in summer, Saga is downwind of the Asian continent most of the year.…”