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Zusammenfassung:
The continuous development and improvement of weather and climate models poses a great challenge to atmospheric remote sensing. For the evaluation of the models, increasingly better-resolved measurements and methods are needed. For continuous observations of temperature under all weather conditions and especially during rain conventional approaches fail. A microwave radiometer is usually not suited for retrieval of temperature profiles in rain because for sufficiently large rain rates the blower mitigation of rain wetting the instrument’s radome fail. Then the signal from the liquid water accumulated on the radomes dominates the signal. This can be avoided by measuring only off-zenith, i.e., at lower elevation angles, because the instrument’s radome is usually wet at its top. Furthermore, one can reduce the influence by rain by using only the higher frequencies which are almost saturated anyway. A cross comparison with retrievals for certain angles and certain frequencies gives information about how accurate the rain retrieval is under different conditions, i.e., cloud free or during rain. The retrieval performance is shown on simulations as well as on real measurements. First results show a good performance within the atmospheric boundary layer which is of high interest for precipitation studies. The promising results can help to directly observe the cooling due to precipitation evaporation and better quantify the according cooling rates within the atmospheric boundary layer.
