Simulations of the Atlantic Ocean with a Free Surface Sigma Coordinate Ocean Model

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Ezer, Tal, Mellor, George L.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ODU Digital Commons 1997
• Subjects: Atlantic Ocean; Circulation modelling; Free surface sigma coordinate; Greenland Sea; Heat transfer; Climate; Oceanography; Greenland
• Online Access: https://digitalcommons.odu.edu/ccpo_pubs/118; https://doi.org/10.1029/97JC00984; https://digitalcommons.odu.edu/context/ccpo_pubs/article/1133/viewcontent/Ezer_et_al_1997_Journal_of_Geophysical_Research__Solid_Earth__1978_2012_.pdf

A sigma coordinate, free surface numerical model with turbulence dynamics has been implemented for the Atlantic Ocean and the Greenland Sea, from 80°S to 80°N. It is driven at the surface by monthly mean sea surface temperature and wind stress climatologies and is executed for 30 years. This is the first time that a model of this type, previously used mostly for coastal and regional simulations, has been implemented for the entire Atlantic Ocean and run for a long period of time. The model horizontal circulation, thermohaline overturning circulation, and meridional heat fluxes are described; the results are compared with observations and the results of other models. The model produces intense deep western boundary currents and complicated gyre structures associated with small-scale topographic variations. The meridional. overturning circulation consists of about 14 Sv (1 Sv = 106 m3 s-1) of southward flowing deep water mass crossing the equator and a northward heat flux with a maximum value of more than 1 PW (1015 W). Although the maximum meridional heat flux is comparable to estimates obtained from observations, the amplitude of the seasonal variations of northward heat flux across 26°N is underestimated in comparison with observations; it is similar to that obtained by other models.