CAROb microwave radiometer

A Radiometrics radiometer with 21 channels between 22 and 30 GHz and a single channel at 89 GHz is used to establish continuous water vapor path and liquid water paths. These take advantage of a water vapor absorption line at 22.035 Ghz. We are operating the radiometer at the five frequencies of 23.0234, 23.834, 26.234, 30, and 89 GHz. Two (23.834 and 30 GHz) are used by standard 2-channel radiometers, the 89 GHz channel allows for more sensitive low-LWP measurements and the other two channels are used by standard microwave profilers and may help us establish humidity vertical profiles. A Vaisala weather station additionally measures ambient temperature, relative humidity, wind speeds and direction. The radiometer was deployed to the equatorial Indian Ocean Oct. 2011-Jan. 2012 and will resume at CAROb in February, 2012.