Physical Sciences and Mathematics Commons^™

The Pressure Gradient Conundrum Of Sigma Coordinate Ocean Models, George L. Mellor, Tal Ezer, Lie-Yauw Oey

CCPO Publications

It is shown that the differencing scheme cited here, though conventional, is not hydrostatically inconsistent; the sigma coordinate, pressure gradient error decreases with the square of the vertical and horizontal grid size. Furthermore, it is shown that the pressure gradient error is advectively eliminated after a long time integration. At the other extreme, it is shown that diagnostic calculations of the North Atlantic Ocean using rather coarse resolution, and where the temperature and salinity and the pressure gradient error are held constant, do not exhibit significant differences when compared to a calculation where horizontal pressure gradients are computed on z-level …