Evidence for Predictive Skill of High-Latitude Climate Due to Midsummer Sea Ice Extent Anomalies

• Main Authors: He, Shengping, Knudsen, Erlend M., Thompson, David W. J., Furevik, Tore
• Format: Article in Journal/Newspaper
• Language: English
• Published: AMER GEOPHYSICAL UNION 2018
• Subjects: ddc:no; Arctic; Arctic Ocean; Arctic Basin; Climate change; Sea ice
• Online Access: https://kups.ub.uni-koeln.de/17273/

Previous work has explored the linkages between Arctic sea ice extent (SIE) anomalies at the end of the summer melt season and high-latitude climate. Here we show that Arctic midsummer SIE anomalies provide predictive skill on time scales of similar to 2-3months for high-latitude climate. Midsummers characterized by low SIE are associated with significant positive temperature and easterly wind anomalies throughout the high-latitude troposphere through September and significant positive temperature anomalies at the Arctic surface into October. The inferred predictive skill for autumn climate derives from the persistence of the sea ice field. It is robust throughout the Arctic basin and is supported in climate models from the fifth phase of the Coupled Model Intercomparison Project archive and in prediction experiments from the Arctic Predictability and Prediction on Seasonal to Interannual Time scales project. It is theorized that the predictive skill derives from (1) the anomalous storage of heat in the Arctic Ocean during periods of low summertime SIE and (2) the delayed formation of sea ice during the following autumn months. Plain Language Summary Here we analyze the evidence for predictability of high-latitude climate that derives from Arctic sea ice extent (SIE) anomalies. We demonstrate that the continuous observed lagged correlations between Arctic sea ice anomalies and Arctic/high-latitude climate are most robust in association with midsummer (July) SIE. The linkages between midsummer SIE anomalies and Arctic/high-latitude climate are significant well into autumn and have potential implications for the prediction of high-latitude climate up to 3months in advance. The results have implications for the influence of long-term decreases in summertime sea ice on climate change over the high latitudes.