Yngvar T. Gjessing

Snow contamination from washout/rainout and dry deposition

Abstract The deposition of air pollutants in the Bergen region, Western Norway, is investigated by a very simple and inexpensive method. Dry snow was sampled from the ground at 46 locations just after a snowfall and then three days later. Consistent and logical patterns for the two days were found for sulphate, magnesium, calcium, zinc, pH value and conductivity. The rate of the dry deposition in the rural areas was significantly smaller than the rate of washout/rainout. In the city area these two rates were of the same magnitude.

Episodic variations of snow contamination of an Arctic snowfield

The distribution with depth of 5 different ions in two corresponding 3m snow profiles at Nordaustlandet (79°30′N, 24°E, 600 m a.s.l.) shows a close co-variation between ions of presumptively anthropogenic origin and non-correlation between these and ions of marine origin. The trajectories of the airmasses corresponding to the layer with maximum concentrations of NO3−, NH4+ and SO42− of non-marine origin indicate that these airmasses some 24 h earlier passed central USSR or the Baltic region and during the preceding 24 h were more or less stagnant.

Excess and deficit of sulfate in polar snow

The SO42−Na+, SO42−Cl− and SO42−Mg2+ ratios in deposited snow in the coastal area of Antarctica are markedly lower than for sea water. The mean deficit w.r.t. sea water Na+ for 10 samples from a 1 m snow layer close to the shelf edge was approx. 1400 ng m−3 and 1 km from the shelf edge the mean deficit of 30 samples was 700 ng m −3. Here the annual accumulation was 600 kg m−2 which corresponds to a SO42− deficit of 300 mg m−2 a−1. Precipitation and newly fallen snow in the same area have positive excess SO42−. Anomalous ratios of the principle metallic ions of the upper 1 mm of the ocean or loss of SO42− from the snow to the atmosphere by volatilization have been tested by, respectively, simple field experiments and laboratory experiments. Such effects were not detectable. The most reasonable explanations for the observed SO42− deficit in snow are contributions from rime deposits with a deficit of SO42− and deposition of frozen sea drops which have gone through a separation process of Na2SO4 and NaCl during freezing.

Microclimates and water budget of algae, lichens and a moss on some nunataks in Queen Maud Land

During the Norwegian Antarctic Expedition of 1984–1985, land parties worked in the area of Mühlig-Hofmannfjella and Gjelsvikfjella in Queen Maud Land (5° 20′E, 1° 37′W, 1000–1600 m a.s.l.). The nunataks in this area, which represents one of the climatic limits for terrestrial life on earth, is among those areas absorbing the highest quantity of shortwave radiation during a period of 24 h in summer. In spite of this the air temperature never, or very seldom, exceeds 0° C. The limiting factor for photosynthesis over most of the summer was water availability. Melt-water plays an important role in spring. During rest of the growth season, water from condensation is probably the most important water source for plants. On calm nights the rate of condensation during 6 h may reach 0.5 mm, which constitutes only 10%–30% of daily potential evapotranspiration. Plants situated in narrow clefts or shielded by stone blocks have the highest rate of potential photosynthesis. These locations are shielded from direct solar radiation most of the time, but the radiation from surrounding stone surfaces is higher than from the atmosphere and heat loss by turbulence is smaller than for exposed locations. These locations also probably have the highest rate of actual photosynthesis.