Comparative analysis buoy observations of wind speed over the Arabian Sea with Era-interim, IMDAA, NCEP-FNL, and Scatsat-1

The present study attempted to assess wind speed estimates from the new generation reanalysis datasets Era-interim, IMDAA, analysis dataset NCEP-FNL and satellite observation from Scatsat-1 against the buoy observations over the Arabian Sea. Three moored buoy observation data were considered, one offshore-AD08, two onshore CB02, and CB04. One representative month of 2017 from three seasons was considered for this study, Pre-Monsoon (April), Monsoon (July), and Post-Monsoon (Sept). The results indicate that all the datasets reasonably match the offshore buoy AD08, but the difference with the observation increases with the nearshore buoys. However, the newly launched IMDAA dataset was performing best for the monsoon period. Results indicated that the distribution of the nearshore buoys, these datasets cannot capture the topography induced wind distribution due to their insufficient resolving capability and inaccurate representation of the topography. The IMDAA data was found to perform significantly better than its predecessor Era-interim. Daily averaged wind speed comparison showed high (positive/negative) biases, which indicates that the improved bias correction techniques in the reanalysis datasets resulted in a substantial shift towards an inadequate representation of the surface winds, especially for the nearshore buoys. NCEP-FNL data was found to show interesting results compared to the observations, which indicated it be a suitable alternative to the reanalysis dataset for operational purposes due to the fast and up-to-date availability of the product.