Community:Email 14mar12

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From Ingrid Cnossen ( on Wed March 14, 2012.

Dear colleagues,

I wrote a book chapter entitled "Climate change in the upper atmosphere" which may be of interest to some of you. The full chapter can be downloaded here free of charge:

The abstract is given below.

Thanks, Ingrid


Climate Change in the Upper Atmosphere Ingrid Cnossen, High Altitude Observatory, National Center for Atmospheric Research, USA

In the upper atmosphere, a long-term cooling trend has been observed, along with a corresponding reduction in density at fixed height (the result of thermal contraction) and changes in the ionosphere. An increase in the concentration of CO2, a coolant in the upper atmosphere, is responsible for some of the observed change. However, model estimates of the effects of historical changes in CO2 concentration tend to be much smaller than the observed trends in the thermosphere (~100-500 km altitude). Other factors that may influence the climate of the upper atmosphere must therefore be considered and quantified as well in order to explain the observed changes. The chapter reviews our current knowledge of the effects of changes in composition (CO2, ozone, methane, and water vapor), the secular variation of the Earth’s magnetic field, long-term changes in solar and geomagnetic activity, and changes in tides propagating upwards from the lower atmosphere.

-- Dr. Ingrid Cnossen Post-doctoral fellow High Altitude Observatory National Center for Atmospheric Research 3080 Center Green Drive Boulder, CO 80301 USA tel.: 1-303-497-1505 e-mail: _______________________________________________ Cedar_email mailing list