On the connection between upper atmospheric dynamics and tropospheric parameters: Correlation between mesopause region winds and the North Atlantic Oscillation.

The middle- and high-latitude stratospheric and mesospheric wind field in winter is dominated by the stratospheric polar vortex, which reaches up into the mesopause region and leads to westerly winds there in winter. On the other hand, the tropospheric mean winter wind field is also connected with the stratospheric polar vortex, which thus can be considered as being extended from the lower up to the upper atmosphere. It is found that the January and February mesopause region zonal winds, as measured at the Collm Observatory of the University of Leipzig, are closely connected with the North Atlantic Oscillation (NAO) that can be considered as a measure for part of the northern hemispheric mean circulation in the Atlantic and Europe domain, since it influences the circulation over that domain. The NAO itself is found to be a measure for Central Europe winter winds and temperatures, since large NAO indices are connected with stronger westerlies in Central Europe. Thus also the mesopause region winds are positively correlated to the Central European winter surface temperatures.