Japan Geoscience Union Meeting 2014

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Poster

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

[A-AS22_1PO1] Atmospheric Chemistry

Thu. May 1, 2014 6:15 PM - 7:30 PM Poster (3F)

Convener:*Takegawa Nobuyuki(Research Center for Advanced Science and Technology, University of Tokyo), Yousuke Sawa(Geochemical Research Department, Meteorological Research Institute), Yugo Kanaya Yugo(Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology), Kenshi Takahashi(Research Institute for Sustainable Humanosphere, Kyoto University), Hiroshi Tanimoto(National Institute for Environmental Studies)

6:15 PM - 7:30 PM

[AAS22-P28] Validation of GOSAT SWIR xCH4 using TCCON and Airborne Measurements

*Chisa IWASAKI1, Sachiko HAYASHIDA1, Akiko ONO1, Toshinobu MACHIDA2 (1.Faculty of Science, Nara Women's University, 2.NIES)

Keywords:GOSAT, validation, methane, cloud screening, aircraft

As methane (CH4) is one of the most important Short-Lived Climate Pollutants (SLCPs), global monitoring of atmospheric CH4 with enough accuracy is expected to estimate its sources and sinks. For measurements of global distribution of CO2 and CH4 concentration from space, the Greenhouse gases Observing SATellite (GOSAT) was launched in 2009, and has continued measurements up to the present. However, cloud interferes satellite observation. To understand CH4 emission from a cloudy region, the selection of an adequate criterion of cloud screening, and validation of data quality are necessary. In this study, we validate the GOSAT CH4 products of the column-averaged dry-air mole fractions (xCH4) derived from Short-Wavelength InfraRed (SWIR) radiation by comparing them with data of Total Carbon Column Observing Network (TCCON). Yoshida et al. (AMT, 2013) had already carried out the validation for the NIES product, but we extended the period and involved more TCCON sites; Yoshida et al. (2013) used data observed at the 13 TCCON sites from June, 2009 to December, 2012 and we used data at the 17 TCCON sites from June, 2009 to August, 2013. We found that the average difference between TCCON and GOSAT for the whole period is -6.0 ± 16.1 ppbv. We also examined the appropriate cloud screening for xCH4 product from RemoTeC-MACC. The product was obtained by using the "proxy method" by which we can obtain more data under cloudy conditions. In this study, we also tried to compare GOSAT data with aircraft measurements over Siberia and other areas.Acknowledgements This research was supported by the Environment Research and Technology Development Fund of the Ministry of the Environment, Japan (A1202). The RemoTeC-MACC product was provided by Dr. Andre Butz (IMK-ASF, Karlsruhe Institute of Technology; KIT).