Quantifying the role of ocean coupling in Arctic amplification and sea-ice loss over the 21st century

Abstract The enhanced warming of the Arctic, relative to other parts of the Earth, a phenomenon known as Arctic amplification, is one of the most striking features of climate change, and has important climatic impacts for the entire Northern Hemisphere. Several mechanisms are believed to be responsi...

Full description

Bibliographic Details
Published in:npj Climate and Atmospheric Science
Main Authors: Rei Chemke, Lorenzo M. Polvani, Jennifer E. Kay, Clara Orbe
Format: Article in Journal/Newspaper
Language:English
Published: Nature Portfolio 2021
Subjects:
geo
Online Access:https://doi.org/10.1038/s41612-021-00204-8
https://doaj.org/article/61048e2ffade48e78ba570dc1492ca84
Description
Summary:Abstract The enhanced warming of the Arctic, relative to other parts of the Earth, a phenomenon known as Arctic amplification, is one of the most striking features of climate change, and has important climatic impacts for the entire Northern Hemisphere. Several mechanisms are believed to be responsible for Arctic amplification; however, a quantitative understanding of their relative importance is still missing. Here, using ensembles of model integrations, we quantify the contribution of ocean coupling, both its thermodynamic and dynamic components, to Arctic amplification over the 20th and 21st centuries. We show that ocean coupling accounts for ~80% of the amplification by 2100. In particular, we show that thermodynamic coupling is responsible for future amplification and sea-ice loss as it overcomes the effect of dynamic coupling which reduces the amplification and sea-ice loss by ~35%. Our results demonstrate the utility of targeted numerical experiments to quantify the role of specific mechanisms in Arctic amplification, for better constraining climate projections.