Microwave radiometry is a suitable technique to measure atmospherictemperature profiles with high temporal resolution during clear sky andcloudy conditions. In this study, we included cloud models in the inversionalgorithm of the microwave radiometer TEMPERA (TEMPErature RAdiometer) todetermine the effect of cloud liquid water on the temperature retrievals. Thecloud models were built based on measurements of cloud base altitude andintegrated liquid water (ILW), all performed at the aerological station(MeteoSwiss) in Payerne (Switzerland). Cloud base altitudes were detectedusing ceilometer measurements while the ILW was measured by a HATPRO(Humidity And Temperature PROfiler) radiometer. To assess the quality of theTEMPERA retrieval when clouds were considered, the resulting temperatureprofiles were compared to 2 years of radiosonde measurements. The TEMPERAinstrument measures radiation at 12 channels in the frequency range from 51to 57 GHz, corresponding to the left wing of the oxygen emission linecomplex. When the full spectral information with all the 12 frequencychannels was used, we found a marked improvement in the temperatureretrievals after including a cloud model. The chosen cloud model influencedthe resulting temperature profile, especially for high clouds and clouds witha large amount of liquid water. Using all 12 channels, however, presentedlarge deviations between different cases, suggesting that additionaluncertainties exist in the lower, more transparent channels. Using lessspectral information with the higher, more opaque channels only also improvedthe temperature profiles when clouds where included, but the influence of thechosen cloud model was less important. We conclude that tropospherictemperature profiles can be optimized by considering clouds in the microwaveretrieval, and that the choice of the cloud model has a direct impact on theresulting temperature profile.
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