Improvement and impact study of satellite derived CMVs over Indian region

Abstract

The derivation of Cloud Motion Vectors (CMVs) using infrared data has been started from  Kalpana-1 in April 2003 and from INSAT-3A recently. In the present technique, the quality check of CMVs was carried out with LAM Model forecast data, which covers the area 40° E - 129° E and 29° S - 45° N).  The CMVs derived below the 29° south were rejected due to non availability of LAM Model forecast data. Recently, the LAM Model forecast is replaced by global forecast and therefore CMVs are now derived over larger area (40° E - 129° E and 45° S - 45° N) resulting a significant increase in the number of good quality CMVs. These CMVs are put on GTS for end users. The Integrated Satellite Wind Monitoring NWP SAF site has recently started storing and monitoring of Kalpana-1 and INSAT-3A derived CMVs. The statistical error analysis has been carried out for the CMVs with different NWP models in order to identify and distinguish error contributions from satellite winds and NWP models. Further, in this paper, we have examined the impact of these data in the MM5 NWP model for a cyclone case study. This study demonstrates the impact of these data in the model to capture wind circulation, surface pressure and rainfall. The impact of additional CMVs data in the model is found positive and beneficial.