The Odden ice feature of the Greenland Sea and its association with atmospheric pressure, wind, and surface flux variability from reanalyses



[1] The Odden sea ice feature of the Greenland Sea is identified in a rotated principal component analysis of Hadley Center winter sea ice concentration data extending from 1951–2005. Time series of the Odden ice extent are evaluated in the context of sea level pressure, surface wind, air temperature, cloud, and energy flux variations using NCEP-NCAR reanalyses. Odden was a recurring feature in winters 1966–1972, during the Great Salinity Anomaly (GSA), and appeared occasionally in the 1980s and 1990s but has occurred rarely since 2000. Odden formation is associated with northernmost Atlantic high pressure, a negative North Atlantic Oscillation, and anomalous westerly winds. Its formation is most highly correlated, however, to air temperature and fluxes of sensible/latent heat, and downward longwave radiation. Air temperature and downward longwave flux anomalies in the preceding autumn are also unusually low in advance of a winter Odden ice cover while heat fluxes are weakly positive. All parameters, including the ice cover anomaly, exhibit significant winter to winter persistence over time.