Spatio-temporal variation of methane over Indian region: Seasonal and inter-annual variation .
Abstract
Methane (CH4) has an important role in the radiation budget and chemistry in the lower and middle atmosphere as a greenhouse and reactive trace gas. The rapid developments in the agriculture and industry over India have lead to the emission of many pollutants like CO, O3, CH4, CO2, SO2 etc into the atmosphere. However, their sources, sinks and concentration levels are poorly understood because of the lack of systematic sampling and monitoring. The advent of satellite remote sensing has helped to analyze the chemical composition of atmosphere with good spatial coverage especially over tropical region which was poorly sampled with the existing surface network. This work attempts an analysis of spatial distribution, seasonal cycle and inter annual variation of CH4 over Indian region during 2003-2009 using SCIAMACHY data onboard ENVISAT. Column CH4 varies from 1740-1890 ppbv over Indian region with distinct spatial and temporal features. We observed a dependence of seasonal CH4 variation on rice cultivation, convective activities and changes in boundary layer characteristics. The comparative study using satellite, aircraft and surface measurement shown CH4 has non-homogeneity in its distribution and seasonal variation in different layers of atmosphere. A comparative study of CH4 at different hot spot regions over the globe was carried out which showed prominent hemispherical variations. Large spread in column CH4 was observed at India and Chinese region compared to other regions with a significant seasonal variability. This study points to the blending of satellite, aircraft and surface measurements for the realization of regional distribution of CH4.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2015
- Bibcode:
- 2015AGUFM.A41I0167M
- Keywords:
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- 0322 Constituent sources and sinks;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES