Golden globe Race:
Due to a strongly positive Southern Annular Mode (SAM) during summer in the southern hemisphere, we see the majority of southern ocean storms passing south of the exclusion zone. The positive SAM is a result of multiple factors, mainly due to surface pressure decreasing over the Antarctic and therefore increasing in the mid-latitudes. With the stronger westerlies moving further south, they also propell the Antarctic Circumpolar Current – the world’s strongest current running West to East at about 60ºS. We will thus probably see the fleet being pushed through the Drake Passage with unusual high speeds over ground.
While the positive SAM means less storms for the fleet between 40º and 50ºS, it also means a concentration of very strong westerlies further south. We may see strong southern ocean storms for the fleet when rounding Cape Horn.
If you would like to know more about this weather phenomenon, its impact on glaciers in Patagonia and Antarctic and thus the worldwide climate change, Golden Globe Race recommends this article written by Bethan Davies.