Potential ocean–atmosphere preconditioning of late autumn Barents-Kara sea ice concentration anomaly

Martin P King,Javier Garciá-Serrano

doi:10.3402/tellusa.v68.28580

Abstract

Many recent studies have revealed the importance of the climatic state in November on the seasonal climate of the subsequent winter. In particular, it has been shown that interannual variability of sea ice concentration (SIC) over the Barents-Kara (BK) seas in November is linked to winter atmospheric circulation anomaly that projects on the North Atlantic Oscillation. Understanding the lead–lag processes involving the different components of the climate system from autumn to winter is therefore important. This note presents dynamical interpretation for the ice-ocean–atmosphere relationships that can affect the BK SIC anomaly in late autumn. It is found that cyclonic (anticyclonic) wind anomaly over the Arctic in October, by Ekman drift, can be responsible for positive (negative) SIC in the BK seas in November. The results also suggest that ocean heat transport via the Barents Sea Opening in September and October can contribute to BK SIC anomaly in November.

Highlights

Recent studies have revealed the importance of the November climatic state on the ensuing winter in the Northern Hemisphere (e.g. Garcia-Serrano et al, 2015; King et al, 2016; Stockdale et al, 2015)
It has been shown that interannual variability of sea ice concentration (SIC) in the Barents-Kara (BK) seas in November has statistical link to winter anomalous atmospheric circulation which projects onto the North Atlantic Oscillation
This suggests that, by square of the correlation coefficients, up to 28 % of the November BK SIC variance can be accounted for by sea-level pressure (SLP) in October, but it drops to about 15 % in September and August

Summary

Introduction

Recent studies have revealed the importance of the November climatic state on the ensuing winter in the Northern Hemisphere (e.g. Garcia-Serrano et al, 2015; King et al, 2016; Stockdale et al, 2015). It has been shown that interannual variability of sea ice concentration (SIC) in the Barents-Kara (BK) seas in November has statistical link to winter anomalous atmospheric circulation which projects onto the North Atlantic Oscillation. There is evidence suggesting that sea ice plays a role in setting up the atmospheric states in autumn which are important for initialising the predictions. During our research on the mechanisms that link the autumn and winter climate anomalies (Garcia-Serrano et al, 2015; King et al, 2016), it was noticed that interannual variability of the BK SIC in November (Fig. 1d) is preceded by statistical significant atmospheric circulation anomaly in October. Described briefly above are some practical and scientific motivations for the importance of the leadÁlag relationships of late autumn sea ice and the oceanÁatmosphere interaction

Data and methodology

Results

Conclusions