4th IAGA/ICMA/CAWSES Workshop on Long-Term Changes and Trends in the Atmosphere, Sodankylš, Finland, 4-8 September 2006

Emerging pattern of global change in the upper atmosphere

J. Lastovicka1, R. A. Akmaev2, G. Beig3, J. Bremer4, J. T. Emmert5, C. Jacobi6, M. J. Jarvis7, G. Nedoluha5, Y. I. Portnyagin8, Th.Ulich9

1Institute of Atmospheric Physics, Prague, Czech Republic,
2Cooperative Institute for Research in Environmental Sciences, Boulder, USA,
3Indian Institute of Tropical Meteorology, Pune, India,
4Leibniz-Institute of Atmospheric Physics, Kühlungsborn, Germany,
5Naval Research Laboratory, Washington, USA,
6University of Leipzig, Leipzig, Germany,
7British Antarctic Survey, Cambridge, United Kingdom,
8Institute for Experimental Meteorology, Obninsk, Russia,
9Sodankylä Geophysical Observatory, Sodankylä, Finland

Abstract

In the upper atmosphere, greenhouse gases produce a cooling effect, instead of a warming effect observed in the troposphere. Increases in greenhouse gas concentrations are expected to induce substantial changes in the mesosphere, thermosphere, and ionosphere, including a thermal contraction of these layers. Here we construct for the first time a framework of observed global change in the upper atmosphere, based on trend studies of various available parameters. The picture we obtain is qualitative, and contains several gaps and a few discrepancies, but the overall pattern of observed long-term changes throughout the upper atmosphere is consistent with model predictions of the effect of greenhouse gas increases. Both consistent results and those where there are some discrepancies will be presented in more details. Together with the large body of lower atmospheric trend research, our synthesis indicates that anthropogenic emissions of greenhouse gases are affecting the atmosphere at nearly all altitudes between ground and space.