Geophysical Research Letters

Impact of solar-induced stratospheric ozone decline on Southern Hemisphere westerlies during the Late Maunder Minimum



[1] The Southern Hemisphere Westerly Winds (SWW) constitute an important zonal circulation system that dominates the dynamics of the Southern Hemisphere mid-latitudes. In the present study, we analyze results from two transient simulations (1630–2000 AD) conducted with the coupled atmosphere-ocean model EGMAM (ECHO-G with Middle Atmosphere Model): one simulation with fixed stratospheric ozone concentration, and one with solar-induced variations in stratospheric ozone content. The results suggest that during periods of lower solar activity, the annual-mean SWW tend to get weaker on their poleward side and shift towards the equator. The SWW shift is more intense and robust for the simulation with varying stratospheric ozone, suggesting an important influence of solar-induced stratospheric ozone variations on mid-latitude troposphere dynamics. Finally, we present proxy evidence from a high-resolution marine sediment core from the Chilean continental slope (41°S), which strongly supports the model result of an equatorward displacement of the SWW during the Maunder Minimum.