Response of seasonal cycle of carbon dioxide concentration to vegetation activity from satellite observation

The seasonal cycle, a significant character of annual variability in total column CO 2 (XCO 2 ), is highly correlated with the activity of vegetation. However, it is not completely clear how strong the seasonal cycle of XCO 2 is influenced by the vegetation activity in the global scale. This paper assessed the response of XCO 2 variation to vegetation activity using the global 1*1 degree grid data from June 2009 to May 2013, XCO 2 observed by the Greenhouse Gases Observing Satellite (GOSAT) and NDVI from Moderate Resolution Imaging Spectroradiometer (MODIS). The Pearson correlation coefficient (PCC) between the seasonal variations of XCO 2 removed yearly increasing trend and NDVI is obtained for each grid. The results demonstrate PCC significantly shows negative values over the vegetation regions with seasonal change of NDVI in both north and south hemisphere. The amplitude of seasonal variation between them presents a positive correlation. It should be noted that low PCC such as over the tropical area do not means low affection of vegetation on XCO 2 . Moreover, it is found that the correlation between XCO 2 and NDVI could be quantitatively disturbed by the anthropogenic emitting action also. The analysis of more factors inducing the seasonal variation of XCO 2 will be implemented in future.