The effect of ENSO on Arctic sea ice as a source of predictability

Abstract

ENSO is the primary mode of global climate variability but its links to Arctic sea ice are uncertain, in part due to the short observational record. The Community Earth System Model is used to constrain the effect of ENSO on Arctic sea ice concentration and thickness, as well as the sea level pressure, atmospheric temperature and snowfall patterns which drive this response. A deepened Aleutian Low and high pressure over the central Arctic appear to drive a redistribution of the sea ice in the winter and spring following an El Niño compared to a La Niña. El Niño years experience warmer Arctic air temperature and increased melting during summer when compared to La Niña years. These effects are validated, where possible, using satellite and reanalysis data. The shifting ice edge results in variations in the predictability of Arctic sea ice in some regions.