Mass balance inverse modelling of methane in the 1990s using a Chemistry Transport Model

[摘要] A mass balance inverse modelling procedure is applied with a time-dependentmethane concentration boundary condition and a chemical transport modelto relate observed changesin the surface distribution of methane mixing ratios during the 1990sto changes in its surface sources.The model reproduces essentialfeatures of the global methane cycle, such as the latitudinal distributionand seasonal cycle of fluxes, without using a priori knowledge ofmethane fluxes.A detailed description of the temporal and spatial variability ofthe fluxes diagnosed by the inverse procedure is presented,and compared with previously hypothesised changes in the methane budget,and previous inverse modelling studies.The sensitivity of the inverse results to the forcing data supplied bysurface measurements of methane from the NOAA CMDL cooperative airsampling network is also examined.This work serves as an important starting point for future inverse modellingwork examining changes in both the source and sink terms in the methane budgettogether.

[学科分类] 大气科学