Simulation of global atmospheric methane cycle

In the previous study the three-dimensional climatic model, with realistic representation of global circulation, supplemented by the continuity equation for methane (CH4) has been considered as a tracer transport model On the basis of this model there has been performed the simulation of the atmospheric response to the global surface distribution of the background concentration of CH4 measured in the marine boundary layer at the NOAA/CMDL network for 1984-1987. Closed contours of maximum concentrations distinguishing geographical source regions and adjacent areas with steep gradients have been derived at the northern mid-latitudes in the atmospheric boundary layer. The main result of the model experiment is that the given transport model allows to interpolate rather sparse ground-based observations derived from 19 sites. Most of the measurement sites are in remote locations, far from methane sources. As atmospheric methane sinks were not included in the model it was possible to interpret the spatial distribution of the methane simulated only within the atmospheric boundary layer.