Structural changes in long-term trends of the dynamics of the upper atmosphere

• Applicant: Professor Dr. Christoph Jacobi
• Subject Area: Atmospheric Science
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 36432611

Experimental evidence has shown that, differing from the behaviour of middle atmosphere temperature, mesosphere/lower thermosphere (MLT) winds do not exhibit a clear long-term trend pattern, which is probably due to the interplay of lower and middle atmospheric sources of MLT dynamical variations. To clarify the role of different sources in MLT variations, time series of middle atmosphere winds will be investigated with respect to structural changes in long-term trends recently observed. Taking into account the relatively short data series and inhomogeneous time series available, sophisticated statistical tools will be used to assess the time when possible middle atmosphere trends change their structure and the type of these changes. These analyses will be complemented by comparison with variations and trends of troposphere-stratosphere parameters related to dynamics, ozone behaviour, lower ionospheric parameters, and external influence as solar flux, geomagnetic field and cosmic ray flux variations to obtain information on possible sources of middle atmosphere wind trends and their changes. Numerical modelling of the middle atmosphere response to lower atmosphere changes will be performed using state-of-the-art circulation models of the middle atmosphere. Time slice runs based upon reanalysis data will be used to clarify the influence of the lower atmosphere on middle atmosphere trends.

• DFG Programme: Research Grants
• International Connection: Czech Republic, Russia
• Participating Persons: Dr. Jan Lastovicka; Professor Dr. Yuri Portnyagin