Warunki meteorologiczne na Lodowcu Waldemara (NW Spitsbergen) w sezonie letnim 1999 roku

The meteorological measurements were carried out on NW Spitsbergen on the Waldemar Glacier (surface 2.66 km2) in three points: ATA (133 m a.s.l., marginal zone), LW1 (130 m a.s.l., snout of glacier), LW2 (380 m a.s.l., firn part). The base station of Toruń Polar Expedition is situated on the north part of Kaffioyra (KH, 11 m a.s.l.), about 3 km away from glacier. The air temperature and relative air humidity were measured by termohigrographs in standard meteorological boxes, and precipitation by Hellmanns pluwiometer in the period 14.07-8.09.1999. The weather conditions on the Kaffiöyra region are determined by solar and circulation factors. In the summer season 1999 north and east advection of air masses dominated. The meteorological conditions on Waldemar Glacier are formed by the influence of two contrasting environments: the glacier and its moraine foreground. The mean air temperature in summer 1999 at the Kaffiöyra equaled 5.4°C and at the moraine of the Waldemar Glacier (ATA) 5.2°C. On the glacier the air temperature was much lower, and on the snout (LW1) was 4.5°C and decreases with the altitude (LW2 3.2°C) . The average gradient of air temperature between LW1 and LW2 stands was 0.53°C/100 m. Between the warmed up dark moraine ground (ATA) and the melted surface of the glacier a ?thermal jump? occurred (0.4°C on the distance 160 m). The highest maximum of air temperature at KH was 18.1°C, and on the Waldemar Glacier 16.4°C (LW1) and 16.5°C (LW2). The relative air humidity on Spitsbergen are formed under the influence of oceanic water and foehn phenomena. In summer season 1999 the mean relative air humidity was 84% at the Kaffioyra and increased with the altitude on the Waldemar Glacier (LW1 ? 86%, LW2 ?89%). In the period 21-07-31.08 at the Kaffioyra sums of the precipitation equaled 58.4 mm and on the glacier: 85.2 mm (133 m a.s.l.), 100,6 mm (233 m a.s.l.), 108.9 mm (380 m a.s.l.) and 131.8 mm (421 m a.s.l.). In summer season the meteorological conditions on the Waldemar Glacier show a large variability. It is a result of incoming air masses, warm from moraine foreground up the glacier and cool from the glacier plateau, from the interior of Spitsbergen.