Sea-ice and meteorological conditions in northern Baffin Bay and the NorthWater Polynya between 1979 and 1996

In this paper we provide an overview of the meteorological and sea-ice cond itions within the northern portion of Baffin Bay and the region of the Nort h Water (NOW) Polynya between Ellesmere Island and Greenland. Our results i ndicate an east-west temperature gradient across the NOW and Baffin Bay reg ions with colder temperatures on the Ellesmere Island coast (-14 degreesC) and warmer temperatures on the Greenland coast (-9 degreesC). This is cause d by warm air advection (upper level and boundary layer) due to prevailing atmospheric flows. The sea level pressure (SLP) pattern exhibits a pronounc ed inverted trough in Baffin Bay extending from a quasi-stationary low sout h of Greenland. The trough deepens in winter thereby tightening the pressur e gradient across the NOW region. This results in maximum winds (northerly) in winter. The trough also creates a mean cyclonic gyre in Baffin Bay, mir roring the spatial pattern of annual ice concentrations. The polynya is for med between November and March as a result of the annual appearance of an i ce bridge in Smith Sound along with a northerly surface flow. The formation and duration of the ice bridge is shown to be highly variable and appears to be forming later and breaking earlier in the 1990s compared with the 198 0s. The average sea-ice formation and decay dates closely follow the mean t emperature spatial pattern, illustrating a strong atmosphere-surface coupli ng. Results show that the NOW region has several distinct sea-ice anomaly p atterns. These patterns consist of areas of high anomalous concentrations o f sea ice which are consistent spatially and temporally. A bridge dipole op erates out of phase (e.g., as ice anomalies increase ( decrease) in Nares S trait they decrease (increase) in Smith Sound). A gyre dipole operates in p hase between Smith Sound and the south-west coast of Greenland. When concen tration anomalies are negative (positive) in Smith Sound they are also nega tive (positive) along the south-west coast of Greenland. We speculate that these links may be useful indicators of the response of the NOW region to c limate variability and change.