Observed winter Barents Kara Sea ice variations induce prominent sub-decadal variability and a multi-decadal trend in the Warm Arctic Cold Eurasia pattern
Journal
Environmental Research Letters
Journal Volume
19
Journal Issue
2
Date Issued
2024-02-01
Author(s)
Ghosh, Rohit
Manzini, Elisa
Gao, Yongqi
Gastineau, Guillaume
Cherchi, Annalisa
Frankignoul, Claude
Kwon, Young Oh
Suo, Lingling
Tyrlis, Evangelos
Mecking, Jennifer V.
Tian, Tian
Zhang, Ying
Matei, Daniela
Abstract
The observed winter Barents-Kara Sea (BKS) sea ice concentration (SIC) has shown a close association with the second empirical orthogonal function (EOF) mode of Eurasian winter surface air temperature (SAT) variability, known as Warm Arctic Cold Eurasia (WACE) pattern. However, the potential role of BKS SIC on this WACE pattern of variability and on its long-term trend remains elusive. Here, we show that from 1979 to 2022, the winter BKS SIC and WACE association is most prominent and statistically significant for the variability at the sub-decadal time scale for 5-6 years. We also show the critical role of the multi-decadal trend in the principal component of the WACE mode of variability for explaining the overall Eurasian winter temperature trend over the same period. Furthermore, a large multi-model ensemble of atmosphere-only experiments from 1979 to 2014, with and without the observed Arctic SIC forcing, suggests that the BKS SIC variations induce this observed sub-decadal variability and the multi-decadal trend in the WACE. Additionally, we analyse the model simulated first or the leading EOF mode of Eurasian winter SAT variability, which in observations, closely relates to the Arctic Oscillation (AO). We find a weaker association of this mode to AO and a statistically significant positive trend in our ensemble simulation, opposite to that found in observation. This contrasting nature reflects excessive hemispheric warming in the models, partly contributed by the modelled Arctic Sea ice loss.
Subjects
Barents-Kara Sea ice | Eurasia | Warm Arctic Cold Eurasia | winter
Type
journal article