Spatial-Temporal Variability of Northern Hemisphere Sea Ice Concentrations and Concurrent Atmospheric Teleconnections

Abstract

Because the Arctic is so integrally connected with the Earth's climate system, there is concern that the recent era of global warming has irreversibly altered the polar sea ice cover. This can have global consequences. However, we need to improve our knowledge of sea ice-atmosphere teleconnections if we are to increase our confidence in such climate change scenarios. In this paper, we apply the method of principal components analysis to twenty years of pentad-averaged Arctic sea ice concentration anomaly data derived from satellite observations to retrieve the most significant spatial and temporal patterns. We then linked these patterns to coincident 500 mb geopotential height (500Z) data. The strongest spatial-temporal ice concentration anomaly pattern over the 1980-1999 period was the phase-shifted anomalies between the Greenland and Barents Seas and the Labrador Sea and in Davis Strait. We found this pattern to be associated with strong low pressure anomalies over the North Atlantic and is significantly correlated with the large-scale atmospheric patterns of the North Atlantic Oscillation and El Niño. Other regions where spatially and temporally consistent patterns of anomalous ice concentrations were identified include the Beaufort Sea, on the Siberian side of the Arctic Basin,and the Sea of Okhotsk. We identify the atmospheric patterns coincident with these anomalies. We conclude that our approach of linking PCA results of ice anomaly data with highly loading 500Z patterns is an effective analysis method. We recommend that this study be extended to link full atmospheric PCA results with the sea ice pentads used here.

Keywords: arctic sea ice, climate change, North Atlantic Os cillation, principal components analysis, teleconnections