Reconstruction of the methane fluxes from the west Siberia gas fields by the 3D regional chemical transport model

A 3D mesoscale tropospheric photochemical transport model of high spatial r esolution has been developed and used for assessment of the methane concent rations and methane emission in the West Siberian region of intensive minin g of natural gas and oil deposits. The model is validated against the measu rements of methane concentration at the surface and in the lower tropospher e collected during July 1993 and June 1996 experiments. Comparison of the s imulated and observed concentrations allowed to estimate that during the ab ove periods the average natural methane fluxes were as high as 65 mg m(-2) day(-1). The anthropogenic methane fluxes (leakage from gas deposits) integ rated over model domain during the same time period were about 20% of the t otal methane emission from relevant areas. (C) 2000 Elsevier Science Ltd. A ll rights reserved.