Abstract
High resolution eddy resolving models are shown to be necessary for
simulating submesoscale variability of the ocean. Although how these
resolved submesoscale features impact the larger scale simulations is
not yet clear. Here, using satellite observation and model experiments
based on Modular Ocean Model (MOM5), we investigate the impact of model
resolution in the sea level variability of the north Indian Ocean in the
seasonal and intraseasonal time scale. While one model experiment uses
uniform 0.25 o horizontal resolution with 40 vertical levels, in the
second experiment model resolution is increase to uniform 0.05 o in
horizontal with 50 vertical levels. The high resolution model shows
significant improvement in simulating mean sea level and its variability
especially along the coast of India, in the equatorial regime and in the
western Arabian Sea. The Great Whirl and its extension become more
realistic as the resolution increases. We show that these improvements
are owing to the better representation of the mesoscale variability of
the upper ocean water column. Further, we show that the coarser model
tends to get biased towards wind-driven Ekman circulation in the open
ocean and produce stronger seasonal signal along the coast.