Dependence of the upper middle atmosphere on tropospheric circulation:: Correlation of European winter rainfall and midlatitude mesopause region zonal winds

The winter midlatitude upper mesosphere/lower thermosphere zonal winds are connected with the northern hemisphere troposphere circulation, such that mesopause region zonal westerly winds are stronger when North Atlantic westerly winds onto Europe are stronger. Since European rainfall rates are connected with the North Atlantic tropospheric circulation, e.g. expressed through a connection with the North Atlantic Oscillation, this leads to a connection between European rainfall and mesopause region circulation, too. Winter rainfall over Northern Europe is larger, when the upper atmosphere zonal prevailing wind is stronger, while in the mediterranean an opposite correlation is found. However, this connection does not give a hint of a direct coupling between upper mesosphere/lower thermosphere winds and European rainfall, but rather shows that both European tropospheric and upper atmosphere dynamical parameters are both included into large-scale circulation patterns.