Lecturer: Stefan BÃ¼hler (Institut fÃ¼r Umweltphysik, Univ. Bremen) Date: 2005-11-30 10:00 Place: Sal B, IRV
Measuring humidity and ice clouds in the atmosphere with space instruments
Water vapor is the most important greenhouse gas. Nevertheless, the absolute amount of water vapor in the upper troposphere is currently poorly known, since traditional measurement methods, radiosondes and infrared satellite instruments, show large discrepancies. A relatively new complementary water vapor data set is that of the operational microwave sounders, AMSU-B and SSM-T2, on the polar orbiting NOAA and DMSP satellites. The talk outlines the role of water vapor for the atmospheric energy balance and describes how the microwave satellite data record can be used to study the water vapor distribution. In the second part of the talk the role of cirrus clouds is discussed, which are the source of another significant uncertainty in our understanding of the climate system. Cirrus clouds can also be detected with microwave instruments, as will be demonstrated in the talk. However, to really study cirrus clouds we would like to have instruments measuring higher frequencies in the sub-mm spectral range. Such an instrument, called CIWSIR (Cloud Ice Water Sub-millimeter Imaging Radiometer), has recently been proposed to the European Space Agency ESA.
Created 2005-11-25 16:03:22 by Rick McGregor Last changed 2005-11-25 16:03:22 by Rick McGregor