Mapping the FTS SWIR L2 product of XCO2 and XCH4 data from the GOSAT by the Kriging method - a case study in East Asia

Developed by Japan, the Greenhouse Gases Observing Satellite (GOSAT), also known as IBUKI, was successfully launched on 23 January 2009 to monitor greenhouse gases on the Earth's surface. Observations started in April 2009, and data on Levels 1, 2 and 3 products became available to general users in November 2009, February 2010 and October 2010, respectively. For this article, the Kriging method was proposed to generate the spatial distribution of the daily GOSAT XCO2 and XCH4 data within the region of East Asia from June 2009 to May 2010. The relationship between the distance and difference of daily data for each month were represented by variogram models. The concentration distributions of XCO2 and XCH4 in East Asia can be intuitively seen on a Kriging interpolation map. Seasonal changes were observed. The concentration of XCO2 was high in winter and spring, which might be due to smoke and dust from coal burning. The concentration of XCH4 changed significantly with latitude in autumn and winter, mainly according to temperature changes. In addition, by comparison, the Level 2 Kriging interpolation values were lower than ground observed data and consistent with the higher tendency of Level 3 data.