Contribution of wind to Polar sea ice retreat

The relationship between near-surface wind speed and sea-ice concentration remains unclear for two main reasons: 1) observed wind speeds over polar regions are very sparse, and 2) simulated winds by climate models are dependent on subjective parameterizations of boundary layer stratification. Here, we use observation-based data (passive microwave sea-ice concentration and 5 different reanalysis datasets) together with output from 26 climate models (from the CMIP5 archive) to quantify the relationships between near-surface wind speed and sea ice concentration over the past 40 years. The reanalysis datasets are generally close to reality because they ingest a vast amounts of historical observations (approximately 7-9 million from satellites and in-situ every 6-12 hours over the analyzed period 1979-2018) into global estimates using advanced modeling and data assimilation system. We find strong relationships between near-surface wind speed and sea ice concentration that are consistent among the 5 reanalysis datasets, such that less ice cover is associated with stronger winds. The models generally produce similar results but differ in magnitude, and one model even simulate the opposite relationship.