Development of a triply nested eddy resolving north Indian Ocean model

Friday, 19 December 2014
Hasibur Rahaman, INCOIS,Ocean Valley, Hyderabad, India and Matthew Harrison, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States
High resolution triply nested eddy resolving regional Indian Ocean model has been developed using recent version of Modular Ocean Model (MOM4p1). A multi-model approach is adopted using MOM4p1 and INCOIS-GODAS. In this setup, regional model (IOM-1/4) in the Indian Ocean region with 1/4° (~ 25 km) horizontal resolution (eddy permitting) and less than 1 meter vertical resolution in the near the surface, takes initial and lateral boundary condition from INCOIS-GODAS. IOM-1/4 solutions are then used to give lateral boundary condition to an eddy resolving (1/12° horizontal resolution) north Indian Ocean Model (IOM-1/12). The physics in eddy permitting and eddy resolving model is same. The forcing is same in all three model simulations. The analysis of model solutions during January 2010 to June 2013 shows significant improvement in upper ocean variability in IOM-12 as compared to INCOIS-GODAS and IOM-1/4. The costal currents along the Indian coast are more realistic in eddy resolving MOM-1/12 as compared to MOM-1/4 and INCOIS-GODAS.