SEMINAR

A Study of Ocean Currents in Strategic Straits Using High-Resolution Parallel Ocean Models

* Oceanography Division, Naval Research Laboratory

# CAST, Mississippi State University

ABSTRACT

Data parallel versions of the DieCAST z-level 3-D ocean model have been used to compute the circulation in ocean basins adjoining strategic straits.

Oceanic straits generally exert a disproportionately great influence on circulation when one considers their small size and volume. The three well-known straits chosen for the simulation are the Strait of Gibraltar (separating the Atlantic from the Mediterranean), the Strait of Otranto (separating the Adriatic Sea from the rest of the Mediterranean), and the Fram Strait (separating the Arctic Basin from the Greenland Sea).

The discussion concerning the dynamics will focus on the nature of the flow reversals, on the entering and exiting water masses passing at the same depth, or below each other. In some straits, multiple reversals are possible. The discussion concerning numerics will focus on the fourth-order accuracy of the various terms (e.g. pressure gradients, advection, divergence, etc.)

The total computational grids were 378x170x31 for the Mediterranean, and 461x212x23 for the North Atlantic-Arctic domain. The Mediterranean runs were carried out mostly on the SGI Origin 2000, using the pfa version of the SGI parallel compiler, with good scaling up to 16 processors. The Arctic runs were carried out on both the CM5-E and the Origin 2000 at NRL-DC, with data-parallel versions of the code (CM Fortran and HPF).

WHERE: TEC 101

WHEN(day): Wednesday, October 15th, 1997

WHEN(time): 12:00 NOON

EVERYBODY IS INVITED