Atlantic pycnocline theory scrutinized using a coupled climate model

作者：Levermann Anders^*; Fuerst Johannes Jakob

来源：Geophysical Research Letters, 2010, 37: L14602.

DOI：10.1029/2010GL044180

Simulations with changed Southern Ocean wind-stress, oceanic vertical mixing, surface freshwater forcing and global warming confirm the basic equations of Gnanadesikan's (1999) theory for the Atlantic: one vertical scale, the pycnocline depth D, contributes inversely proportional to low-latitudinal upwelling and linearly to Southern Ocean eddy transport. The maximum Atlantic overturning is confirmed to be quadratic in D but is also shown to be linear in a meridional density difference Delta rho. Our simulations strongly suggest that the theory needs to be complemented by a dynamical equation for Delta rho since changes in both D and Delta rho are significant and mutually independent. While, under global warming D varies strongly and Delta rho is practically constant, the situation is reversed for altered surface freshwater fluxes. Similarly, variations in the meridional length scale of Southern Ocean outcropping require a dynamical equation in order to capture the fundamental behavior of the Atlantic meridional overturning circulation. Citation: Levermann, A., and J. J. Furst (2010), Atlantic pycnocline theory scrutinized using a coupled climate model, Geophys. Res. Lett., 37, L14602, doi:10.1029/2010GL044180.

• 出版日期2010-7-23