Further correction of numerical estimations for anthropogenic methane emissions from Western Siberia gas deposits by applying 3D regional transport model in direct and inverse modes

摘要

The quantitative assessment of anthropogenic methane sources is a very actual problem due to global wanning observed and necessity to decrease the injection of greenhouse gases into the atmosphere. The estimate of leakage from gas deposits varies in a wide range. Our numerical estimates using of 3D regional transport model and measurements sampled during specially organised field campaigns allowed to correct the volume of gas leakage from main Siberian gas deposits, including corresponding gas transport systems. For correction of these estimations the 3D regional transport model in inverse mode is applied, allowing to trace departure points and routes of air masses coming to the sampling points and to estimate the relative input of different parts of West Siberian gas deposits into the sampled CH_4 concentrations. The total anthropogenic methane flux from Western Siberia is evaluated as 2.2+/-0.5 Mt/year or about 0.5% of global annual methane emission.