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<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>We invite
you to contribute to the following session at the next EGU meeting: "Features
of the ionosphere and thermosphere during the recent solar minimum" (<a
href="http://meetingorganizer.copernicus.org/EGU2011/session/7078">http://meetingorganizer.copernicus.org/EGU2011/session/7078</a>).
The European Geosciences Union (EGU) General Assembly 2011 meets in <st1:place
w:st="on"><st1:City w:st="on">Vienna</st1:City>, <st1:country-region w:st="on">Austria</st1:country-region></st1:place>
from 03-08 April. Abstracts are due 10 January via the website at <a
href="http://meetings.copernicus.org/egu2011/"
title="http://meetings.copernicus.org/egu2011/">http://meetings.copernicus.org/egu2011/</a>.<o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>ST3.3<br>
Features of the ionosphere and thermosphere during the recent solar minimum<o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>The
recent cycle 23/24 solar minimum was unusually prolonged compared to the previous
several minima, and it had the most days without sunspots since the 1933
minimum. Weaker forcing of the upper atmosphere by solar EUV irradiance seems
to have contributed to substantial changes in the ionosphere-thermosphere
system. Measurements indicate large departures from empirical models like MSIS and
IRI during the years 2006–2009, and a full explanation of these anomalies
has not yet emerged. On the other hand, the lack of solar variability during
this minimum has made forcing from below (e.g., via planetary and tidal waves)
more prominent, thus affording the opportunity to better understand coupling
with the underlying atmosphere.<o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>We
welcome contributions that compare observations with model predictions during
the recent minimum, provide explanations for the unusual
ionosphere-thermosphere behaviour, or show comparisons with other solar minima.
Also solicited are contributions dealing with the altered wave forcing of the
ionosphere and thermosphere during low solar activity. Observational and modelling
studies are both welcome. <o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>John
Emmert, Hermann Lühr <o:p></o:p></span></font></p>
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