H2O Antarctica Microwave Stratospheric and Tropospheric Radiometers

HAMSTRAD is a microwave radiometer that measures tropospheric water vapour and temperature profiles together with liquid water path above Dome C. Measuring at both 60 GHz (oxygen molecule line (O2) to deduce the temperature) and 183 GHz (H2O line), this unique, state-of-the-art radiometer was installed on site for the first time in January 2009. The measurements of the HAMSTRAD radiometer allow the retrieval of the vertical profiles of water vapour and temperature from the ground to 10-km altitude with vertical resolutions of 30 to 50 m in the Planetary Boundary Layer (PBL), 100 m in the lower free troposphere and 500 m in the upper troposphere-lower stratosphere. The temporal resolution on the instrument (1-7 minutes) combined with the observations performed by other instruments on the site (LIDAR, radiosondes, Surface Radiations) allows for detection and analysis of atmospheric processes such as the diurnal evolution of the PBL and the presence of clouds and diamond dust together with Supercooled Liquid Water Clouds (SLWCs). We would like to take the opportunity of using HAMSTRAD in order: 1) to provide original observations of temperature, water vapour and liquid water in the troposphere to the scientific community (data are freely accessible at http://www.umr-cnrm.fr/spip.php?article961), and 2) to continue our scientific analyses on SLWCs, trends and radiative impact of clouds on the Antarctic climate by combining HAMSTRAD observations with measurements performed at Dome C (through French-Italian collaborations) and model outputs (ARPEGE, ARPEGE-Climat, ERA5).