Representation of the mean Atlantic Subtropical Cells in CMIP6 models
Published in Journal of Geophysical Research: Oceans, 2022
The Atlantic Subtropical Cells (STCs) consist of poleward Ekman transport in the surface layer, subduction in the subtropics, and equatorward transport in the thermocline layer that largely compensates the surface Ekman divergence and closes the STCs via equatorial upwelling. As a result, the STCs play an important role in connecting the tropical and subtropical Atlantic Ocean, in terms of heat, freshwater, oxygen, and nutrients exchange. In this study, we evaluated the performance of CMIP6 climate models in simulation the Atlantic STCs. The models generally have a weake southern STC cell and weaker EUC. The large inter-model spread suggests that the mean EUC strength is primarily associated with the intensity of the southeasterly trade winds in the models. Since the trade-wind-induced poleward Ekman transports are regarded as the drivers of the STCs, our results highlight the necessity to improve skills of coupled models to simulate the Southern Hemisphere atmospheric forcing.
Fu, Y., Brandt, P., Tuchen, F. P., Lübbecke, J. F., Wang, C. (2022), Representation of the mean Atlantic Subtropical Cells in CMIP6 models, Journal of Geophysical Research: Oceans, 127, e2021JC018191. https://doi.org/10.1029/2021JC018191