Robust Arctic warming caused by projected Antarctic sea ice loss

• Published in: Environmental Research Letters
• Main Authors: M R England, L M Polvani, L Sun
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP Publishing 2020
• Subjects: sea ice loss; polar climate change; arctic; antarctic; climate model simulations; climate projections; Environmental technology. Sanitary engineering; TD1-1066; Environmental sciences; GE1-350; Science; Q; Physics; QC1-999; Antarctic; Arctic; Bering Sea; Pacific; The Antarctic; aleutian low; Antarc*; Climate change; Sea ice
• Online Access: https://doi.org/10.1088/1748-9326/abaada; https://doaj.org/article/44943380669a4a979cab482aa7ac18bf

Over the coming century, both Arctic and Antarctic sea ice cover are projected to substantially decline. While many studies have documented the potential impacts of projected Arctic sea ice loss on the climate of the mid-latitudes and the tropics, little attention has been paid to the impacts of Antarctic sea ice loss. Here, using comprehensive climate model simulations, we show that the effects of end-of-the-century projected Antarctic sea ice loss extend much further than the tropics, and are able to produce considerable impacts on Arctic climate. Specifically, our model indicates that the Arctic surface will warm by 1 °C and Arctic sea ice extent will decline by 0.5 × 10 ^6 km ^2 in response to future Antarctic sea ice loss. Furthermore, with the aid of additional atmosphere-only simulations, we show that this pole-to-pole effect is mediated by the response of the tropical SSTs to Antarctic sea ice loss: these simulations reveal that Rossby waves originating in the tropical Pacific cause the Aleutian Low to deepen in the boreal winter, bringing warm air into the Arctic, and leading to sea ice loss in the Bering Sea. This pole-to-pole signal highlights the importance of understanding the climate impacts of the projected sea ice loss in the Antarctic, which could be as important as those associated with projected sea ice loss in the Arctic.