Variability of the Southern Hemisphere Westerly Winds during the Holocene: Insights from coupled climate modelling

Abstract

The Southern Hemisphere Westerly Winds (SWW) constitute an important zonal circulation that significantly influences the climate system. Variability of SWW during the Holocene under solar and orbital forcings is studied. In order to study the response of the SWW during the Holocene under the above mentioned forcings, numerical modelling is applied. Comparison with proxy records is also carried out to validate the model results. Taken together, the proxy and model results suggest that centennial-scale periods of lower (higher) solar activity caused equatorward (southward) shifts of the annual mean SWW. Under the influence of orbital forcing, the annual and seasonal mean SWW are subjected to an overall strengthening and poleward shifting trend during the course of the mid-to-late Holocene, except for the austral spring season, where the SWW exhibit an opposite trend of shifting towards the equator.