What controls the atmospheric methane seasonal variability over India?

The weaker CH4 concentrations above Sinhagad (SNG) and Cape Rama (CRI) India during summer monsoon months JJAS may characterize a southern hemisphere origin. In order to verify this we compared the SNG and CRI CH4 with that of the southern hemispheric values taken from Seychelles at Mahe Island (SEY). Noticeably the SEY CH4 has similar seasonal variability as that of SNG and CRI, but with weaker amplitude probably because of its location over the open ocean. The in-phase seasonality between SNG, CRI and SEY thus suggest a possible southern hemisphere origin of CH4 that is observed over the Indian peninsula during JJAS. Model (LMDz) simulated CH4 concentration compared with observations a) SNG (Sinhagad) and SEY (Seychelles), and b) CRI (Cape Rama) and SEY (Seychelles).185