title: Causality in the Winter Interaction Between Extratropical Storm Tracks, Atmospheric Circulation, and Arctic Sea Ice Loss
Creators: name: Mousavizadeh, Morteza
name: Alizadeh, Omid
name: Hodges, Kevin I.
name: Simmonds, Ian
Publisher: name: Humboldt-Universität zu Berlin
Year: 2025
Subjects: subject: Arctic sea ice
subject: sea ice loss
subject: atmosphere‐driven winters
subject: ice‐driven winters
subject: Asian cooling
subject: extratropical storm tracks
subject: 550 Geowissenschaften

description: Global warming is accelerating the decline of Arctic sea ice, with wide‐ranging impacts on the Earth's climate system. Using ERA5 data from 1980 to 2023, we investigated the relationship between winter extratropical storm tracks, atmospheric circulation patterns, and sea ice area (SIA) in three key Arctic regions. We classified the winters into two categories: atmosphere‐driven winters (ADWs), when atmospheric circulation influences sea ice, and ice‐driven winters (IDWs), when sea ice influences atmospheric circulation. This classification was based on the sign of SIA and surface turbulent heat flux anomalies in the Barents‐Kara Sea (BKS), Baffin Bay, Davis Strait, and Labrador Sea (BDL), and Chukchi‐Bering Seas (CBS). Our findings show that in IDWs, reduced SIA has a minor effect on extratropical storm tracks. However, we observed significant midtropospheric cooling over northeastern Asia, aligning with the effects of reduced ice in the BKS during IDWs. This emphasizes the importance of considering the entire tropospheric temperature profile to capture the impact of sea ice loss. In contrast, during ADWs, the BKS and CBS regions experience amplified surface warming and SIA loss due to storm‐induced intrusion of warm and moist air, with sea ice loss in the BKS contributing to strengthening Ural blocking. Although cyclone‐induced heat and moisture intrusion is prevalent, we found no significant trend in track density or mean intensity of positive V extrema in the North Atlantic sector of the Arctic, suggesting that changes in atmospheric circulation are unlikely to be the driver of recent sea ice loss in the BKS.
description: Plain Language Summary: Global warming is causing Arctic sea ice to shrink, which affects the Earth's climate in many ways. Using ERA5 data from 1980 to 2023, we studied how changes in storm patterns, atmospheric conditions, and sea ice are connected in three Arctic regions. We classified winters into two categories: atmosphere‐driven winters (ADWs), in which atmospheric conditions affect sea ice, and ice‐driven winters (IDWs), in which sea ice influences atmospheric conditions. We found that during IDWs, sea ice loss has only a small effect on storm patterns, but it leads to cooling in the midatmosphere over northeastern Asia. This highlights the need to look at temperature changes throughout the entire atmosphere, not just at the surface. In ADWs, storm‐driven warm, moist air leads to more surface warming and sea ice loss, particularly in the Barents‐Kara Sea, where the sea ice loss also contributes to stronger Ural blocking. Although storms in these regions bring heat and moisture, we did not find a clear trend in the number or intensity of storms, suggesting that changes in atmospheric circulation are not the main cause of recent sea ice loss. This research helps to better understand how Arctic sea ice loss and atmospheric changes are linked.
description: Key Points: Recent cooling trend in northeastern Asia occurs in the midtroposphere, primarily driven by sea ice loss in the Barents‐Kara Sea (BKS). Changes in atmospheric circulation are unlikely to be the primary driver of recent sea ice loss in the BKS. In atmosphere‐driven winters, amplified surface warming in the Barents‐Kara and Chukchi Seas result from storm‐driven warm air advection.