The Baffin Bay Region

The Baffin Bay region climatically is very similar to the Atlantic region, particularly to its southern and western sub-regions. The weather in winter in both these regions is shaped mainly by the cyclones developing over the North Atlantic. In the case of the Baffin Bay region, the cyclones move from the source areas through the Davis Strait and Baffin Bay. Cyclones bring large amounts of warmth and moist air to the areas where they enter. Therefore, air temperatures here are markedly higher than in the adjacent regions. Particularly high temperatures are noted in the eastern and the northern parts of the region, where additional heat is introduced into the atmosphere by the West Greenland Current and the stationary "North Water" polynya. In the Baffin Bay region, as a consequence of the great frequency of cyclones, high cloudiness (> 60%), precipitation (50-60 mm), severe winds, and day-to-day variability of all meteorological elements are observed. The topography of the areas surrounding Baffin Bay and the Davis Strait (the mountain relief of Baffin Bay and Greenland with glaciation zones) limits the spatial development of cyclones. As a result, the air temperature significantly decreases on land. The greatest horizontal gradients are noted in the coastal areas, particularly in Greenland. Due to air circulation in the cyclones, northerly and northwesterly winds dominate in the western part of the Baffin Bay region, while in the eastern part, south-easterly winds are prevalent. Such a pattern of wind leads to the occurrence of lower temperatures and precipitation on the coast of Baffin Island than along the coast of Greenland.

In summer, the above-mentioned temperature pattern also occurs but it is mainly connected with the oceanic circulation (a cold current in the west ern region and a warm one in the eastern part). While cyclones are present here, their frequency and strength is lower than in winter. Open waters increase the occurrence of low cloudiness and fogs. Winds have a moderate strength and are less stable over the sea area of the Baffin Bay region. Along the coasts of Baffin Island and Greenland, the easterly and westerly winds dominate, respectively. Fogs are very rare here.

9.6 The Greenland Region

An ice sheet and peripheral glaciers cover more than 80% of Greenland. The plateau of the ice sheet generally exceeds 1200 m a.s.l., and in the highest parts rises to over 3000 m a.s.l. Coastal mountains (see Introduction) also reach this elevation. Besides these important climatic factors, the atmospheric circulation also plays a very important role, particularly in the low elevated areas. The quasi-permanent Greenland anticyclone mainly influences the weather in the northern part, while cyclones coming from the Icelandic depression influence the southern part of Greenland. The cyclones enter Greenland from the southwest; some of the deepest and most vertically developed can cross the southern part of Greenland, sharply changing the weather conditions. However, most often they travel along the western or eastern coasts. The Greenland region, which includes almost the entire island with the exception of the coastal areas not covered by ice, is the coldest part of the Arctic. In the winter months the average temperatures oscillate around -40°C, with minimum temperatures dropping below -60°C. The ice sheet climate is dominated by a surface temperature inversion averaging 400 m in depth. During cyclones the temperature can increase by 20°C to 30°C due to both their transport of warmth and the disturbance of the temperature inversion. This advection of maritime air into the interior is reflected in large interdiurnal temperature changes. In the northern part of Greenland a very low cloudiness and precipitation connected with the dominance of anticyclonic activity and with topographic conditions (on the lee side of the ice sheet) is observed. Both cloudiness and precipitation are higher in the southern half of Greenland, particularly in areas which are elevated and well exposed to the main air streams (the western, southern, and eastern slopes of the Greenland Ice Sheet). On the slopes of the ice sheet, the katabatic winds reaching the maximum speed in the marginal parts of the slopes are a very important feature of the climate.

In summer, according to the investigation made by Serreze et al. (1993), the cyclones tend not to cross Greenland. The differentiation of climatic elements and their variability is therefore lower at this time than in winter. Temperatures are, however, very low and in the northern part the monthly means mostly oscillate between -10°C and -12°C. Extreme temperatures can drop to almost -30°C. The katabatic winds are stable, as in winter, but they are weaker and do not reach the coastal areas.

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