A technique for deriving column-integrated water content using VAS split-window data

Abstract

An algorithm is examined that uses Visible-Infrared Spin Scan Radiometer (VISSR) Atmospheric Sounder (VAS) 11- and 12-μm (split-window) data to derive column-integrated water content (IWC) at mesoscale resolution. The algorithm is physically based and derives its first-guess information from radiosonde data. Results from the test case show reasonable accuracy with the root-mean-square errors at low as ±3.8 mm. IWC analyses depict reasonable gradients and exhibit good spatial and temporal continuity. Furthermore, they provide insight into preferred regions for cumulus cloud and thunderstorm formation. On the average, a mean absolute retrieval error of 2.4 mm (an 8.1% error) and a root-mean-square error of ±2.9 mm are obtained on the case study day. These results compare favorably with those from existing VAS IWC techniques. -from Authors