The impact of ERA-Interim winds on wave generation model performance in the Southern Caspian Sea region

Abstract

The aim of the present work is to evaluate wind dataset in generation of the wave characteristic along the southern basin of the Caspian Sea (SBC). To achieve this purpose, satellite altimetry data, numerical model results and field measurements were considered for 2011. The mixed re-analysis/forecast wind data from European Center for Medium Range Weather Forecast, ERAI_MIXED, are analyzed. Comparisons are made using altimetry data from CERSAT, mixed re-analysis/forecast GFS datasets (GFS_MIXED) and field observation from two buoys and one ADCP located in SBC. The modeling was carried out using the SWAN model over a composite-overlap nested grid system. The results showed that the ERAI_MIXED underestimated wind data in SBC, similar to other datasets from ECMWF and GFS. However, the simulation results implied that using the same configuration for the wave model, ERAI_MIXED led to superior results compared to GFS_MIXED and ERAI_MIXED-COR. Comparison with limited observation showed that ERAI_MIXED data slightly overestimated the wave height in the offshore station and underestimated it at the nearshore buoy. Finally, model results showed that moderate to low wind speed over the SBC might generate the waves up to 4 m wave height.