Validation of a hybrid coordinate ocean model for the Indian Ocean

Abstract

An eddy-permitting HYbrid Coordinate Ocean Model (HYCOM) configured for the Indian Ocean has been validated using both in-situ and satellite observations. The present work focuses on a detailed study of the model’s capability to simulate the major surface and subsurface variables realistically. Weekly data from the model for eight years from 1994 to 2001 are used for the evaluation of the surface data. The model simulation of the circulation patterns in the Indian Ocean for both the monsoon seasons and the transition periods matches well with the observations. Comparisons between model and satellite observations for the sea surface temperature (SST) patterns and its temporal evolution showed that the model produces realistic SSTs. The sea level anomalies (SLA) from the model compared with those from the altimeter data confirmed that the model is in good agreement with the observed SLA. A detailed comparison of results from the daily data of the model with the Argo profiles, for the years from 2002 to 2004 showed that the model has a diffuse thermocline with warming in the subsurface waters, but overall, the model simulates the subsurface temperature and salinity patterns well. The validation of the model indicates that the model results are satisfactory and that with improvements in some of the model configurations, it can be implemented in an operational forecasting system for the Indian Ocean.