Boundary layer temperature profiles by a RASS and a microwave radiometer: Differences, limits and advantages

This study focuses on the accuracy of the temperature profiles obtained with two different remote-sensing instruments: a Doppler Radio-Acoustic Sounding System (RASS) produced by Metek company, and a Microwave Radiometer Meteorological Temperature Profiler (MTP) produced by Kipp & Zonen company. The inter-comparison experiment was carried out at the experimental field facility of the Institute of Atmospheric Sciences and Climate (ISAC) of the Italian National Research Council (CNR) located in the Rome suburbs. To consider the bistatic configuration of the RASS antennas different formulas proposed in the literature were applied and the results compared by using the in situ data given by a tethersonde. A comparison has been made between the RASS and MTP profiles, and their accuracy evaluated by using the tethersonde profiles as a reference. After having computed the absolute temperature from the RASS virtual temperature, the RASS and MTP temperature profiles were super-imposed to the multi-layer atmospheric thermal structure shown by the ISAC acoustic sounder (sodar) to understand at which extent these techniques catch the fine-layer structure of the lower atmosphere.