Wintertime Cloud Cover: A Contributor Towards Inter-Annual Sea Ice Variability
For this study, the ERA-Interim reanalysis is used to diagnose and quantify the contribution of surface radiative forcing by wintertime cloud cover on sea ice during years with anomalous total ice areas. Comparisons between reanalysis of cloud forcing from September through March and passive microwave-derived ice concentrations in September demonstrate a significant inverse correlation between cloud cover during winter and the ice extent at the end of a melt season. Cloud re-emission of longwave radiation in winter months acts to curb the process by which polar seas radiatively cool to space and freeze, so that less winter cloud generally results in thicker sea ice. Here we investigate the role of winter cloud cover as a predictor and contributor to anomalous ice extent over the past 32 years. Our results stand to improve climate model projections of sea ice melt and assign some cause to large year-to-year ice area variability in a warming arctic regime.