Supercooled liquid water content profiles with a new vibrating wire sonde compared to ground-based microwave radiometry

An improved version of the ATEK Corporation vibrating wire sensor, used to measure supercooled cloud liquid water content, was developed by Anasphere Inc and tested during the early months of 2012. The sensor works on the principle that supercooled liquid will freeze to the vibrating wire and reduce the frequency at a known rate proportional to the liquid water content as the sensor rises through the cloud attached to a weather balloon and radiosonde. The disposable Anasphere sensor interfaces with an InterMet Systems iMet radiosonde. This updated supercooled liquid sensor reduces the weight of the instrument while improving performance when compared to the preceding balloon-borne sensor that was developed in the 1980's by Hill and Woffinden. Results from recent laboratory testing show that data collected from the Anasphere sensor compares well to data reported during similar icing tunnel testing in 1989 at Eglin Air Force Base using the ATEK Corporation instrument. These two icing tunnel datasets were used to develop algorithms to calculate the LWC measured from the vibrating wire frequency. Balloon-borne test flights were performed from Boulder, Colorado during February and March of 2012. These flights provided comparisons to integrated liquid water and profiles of liquid water content derived from a collocated multichannel profiling radiometer built and operated by Radiometrics Corporation. Inter-comparison data such as these are invaluable for calibration, verification and validation of remote-sensing instruments. The data gathered from this sensor is important to detection of icing hazards to aircraft and validation of microphysical output from numerical models.