The one-dimensionality of the upper ocean mixing and the role of advection during the POLE experiment

Abstract

Abstract : A one-dimensional mixed layer model (Garwood, 1976, 1977) is used to simulate the mixed layer depth and temperature observed during POLEX, a component of the North Pacific Experiment. POLEX occurred during January-February 1974 with mid-ocean observations (35 deg n, 155 deg w) of temperature and salinity made from R/P FLIP, while FLIP was under free-drift conditions. The results of this simulation show that apparent horizontal advection, due to the drift of R/P FLIP, was important in the heat and salinity budgets, but that vertical mixing and mixed layer depth changes were controlled primarily by the one-dimensional response of the turbulent kinetic energy budget to the local atmospheric forcing. Occasionally, surface salinity flux, due to large precipitation rates, can significantly alter (on the order of tens of meters) the thickness of ocean surface turbulent boundary layer, with demonstrated decrease in thickness during a single period of strong precipitation. (Author)