Study of CO2 variability over India using data from satellites

The concentration levels of CO2 in Earth's atmosphere have rapidly increased over the last 250 years. The source of CO2 in the atmosphere is mainly human activity whereas few natural events such as volcanic activity, natural coal fires etc. also contribute to global CO2. The ground-based measurements provide a strong global constraint on both human and natural CO2 fluxes into the atmosphere. However the identification and characterization of strongest natural sources and sinks, and to discriminate the human CO2 emissions from the natural background, more comprehensive measurement network is needed. Such measurements are essential for the formulation of carbon management policies. For both spatial and temporal studies, detailed global measurements can be provided by satellites. The satellite instruments that provide or have provided atmospheric CO2 information include SCIAMACHY, GOSAT and OCO-2. Alongwith comparative study of SCIAMACHY and GOSAT derived CO2, analysis of recently obtained OCO-2 data is also performed. The GOSAT derived concentration values are about 1{2% smaller than those obtained from SCIAMACHY. The spatial and temporal variability of CO2 over the globe as well as over the Indian land boundary is studied. Comparison with the global view NOAA in-situ data and also location specific data is made.