Japan Geoscience Union Meeting 2016

Presentation information


Symbol A (Atmospheric and Hydrospheric Sciences) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS12] Atmospheric Chemistry

Wed. May 25, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Hitoshi Irie(Center for Environmental Remote Sensing, Chiba University), Toshinobu Machida(National Institute for Environmental Studies), Hiroshi Tanimoto(National Institute for Environmental Studies), Yoko Iwamoto(Faculty of Science Division I, Tokyo University of Science)

5:15 PM - 6:30 PM

[AAS12-P02] Evaluation of GOSAT/TANSO-FTS TIR CH4 data using NICAM-TM and aircraft CH4 data

*Ryosuke Nonogaki2,1, Naoko Saitoh2, Ryoichi Imasu3, Kei Shiomi4, Yosuke Niwa5, Shuji Aoki6, Shinji Morimoto7, Toshinobu Machida8, Hidekazu Matsueda5, Yousuke Sawa5, Kazuhiro Tsuboi5 (1.The Graduate School of Advanced Integration Science, Chiba university, 2.Center for Environmental Remote Sensing, 3.Atmosphere and Ocean Research Institute, The University of Tokyo, 4.JAXA, 5.Meteorological Research Institute, 6.Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University, 7.Graduate School of Science, Tohoku University, 8.National Institute for Environmental Studies)

Keywords:GOSAT, CH4, evaluation

Greenhouse gases Observing SATellite (GOSAT) is the first satellite that was dedicated to the global observations of CO2 and CH4, and was launched on January 23, 2009. CH4 profiles can be retrieved from the thermal infrared (TIR) band of Thermal and Near-infrared Sensor for Carbon Observation Fourier Transform Spectrometer (TANSO-FTS) on board the GOSAT. In this study, we compared CH4 data from the TIR band of TANSO-FTS with CH4 data from Nonhydrostatic ICosahedral Atmospheric Model-based Transport Model (NICAM-TM) [Niwa et al., 2011] and aircraft measurements to evaluate the quality of the TIR CH4 data. First, we compared TIR, NICAM-TM, and CONTRAIL/GRENE CH4 data [Sawa et al., 2015] on the isentropic surfaces in the upper troposphere and lower stratosphere. Second, we compared TIR CH4 data with JMA aircraft CH4 measurement data over Minamitorishima [Niwa et al., 2014] in the upper and middle troposphere. Here, we adopted a distance between TANSO-FTS and the aircraft measurement locations within ±3 degree and a time difference between the two observations within ±3 days as criteria for the comparisons.
From the isentropic analysis, we found that the CONTRAIL/GRENE CH4 concentrations showed a large seasonal variation in the lower stratosphere, while the TIR CH4 data had higher concentrations there than the CONTRAIL/GRENE data and showed a relatively small seasonal variation; the seasonal variation of the NICAM-TM CH4 data were smaller than that of the TIR data. From the profile comparisons over Minamitorishima, we found that the TIR and aircraft CH4 data agreed to each other within 30 ppb at around 6 km in winter and spring, while their differences increased to 30 – 50 ppb in summer. We also investigated the impact of the coincident criteria on the comparisons results. Besides, we analyzed latitudinal distribution of TIR and aircraft CH4 data in the upper troposphere between Atsugi and Minamitorishima.

CONTRAIL/GRENE flask sampling data over Siberia was conducted under the GRENE Arctic Climate Change Research Project. Aircraft measurements between Atsugi and Minamitorishima were conducted by the Japan Meteorological Agency.