Comparative chemical characteristics of precipitation in the Hornsund region ( SW Spitsbergen ) in the years 1993-1994 and 1998-1999

Certain chemical parameters such pH, specific electric conductivity (SpC) and concentrations of chloride ions (CI") have been analysed in samples of precipitation collected close to the Polish Polar Station at Hornsund (PPS), SW Spitsbergen. On the basis of seasonal data from years 1993-1994 and 1998-1999, some differences are apparent from the two sets. There is also a marked difference in the seasonal results, especially with respects to pH values; summer precipitation (pH of which can be as low as 3.78) is much more acidic than winter. This was particularly notable in respect of the summer of 1993, and was presumably the result of a relatively unusual atmospheric circulation and a high influx of airborne contaminants from Europe. The wide variation in specific electrical conductivity measurements is considered to be related to variations in wind direction and speed. That precipitation the highest total dissolved salts, of 11.7 mm w.e. (water equivalent), (November 1993), provided 10.7 g of salt per square metre of tundra near the Polish Polar Station. The proximity of the sea, consequently the development of marine aerosols, largely determines the chemical nature of the precipitation. Thus, variations in the chloride ion concentrations during the study periods more or less reflect the variations in the marine aerosol influences on the nature of the polluted precipitation. An analysis of the atmospheric circulation reveals that the most acid precipitation occurs most frequently in the C-8 type of circulation (cyclonic S + SW) and also, less so, for type C-3 (anticyclonic S + SW)

Carbon dioxide in the tundra soils of SW Spitsbergen and its role in chemical denudation

Measurements of CO2 concentrations in soil air were taken in the summer sea− sons of 1998 and 2001 in SW Spitsbergen. The measurements were carried out in three small non−glaciated catchments in the Hornsund region close to the Polish Polar Station. The pre− liminary measurementsw ere made using a Dräger’spump and ampulesw hich contained an alkaline absorbent (1998). Later (2001), a new more accurate apparatus which uses a gravimetric method wastes ted. A variety of different geographical situationswaschos en for the CO2 measurements. These included areas which differed in respect of the local hydrology, terrain relief, exposure to solar radiation, distance from the sea and quantity of seabird excre− ments in the soil. The measured concentrations of soil CO2 varied between 0.05 and 0.3% (with one exceptionally high value close to 0.5%). Owing to the local conditions, the differ− encesbet ween CO2 concentrations seem closely to relate to the specific properties of each catchment. Much of the biogenic CO2 present in water that circulates in tundra catchments which have a limestone foundation becomes involved in the dissolution of that limestone. In July 2001, about 40% of the CO2 was used in the dissolution of the carbonate rocks (30.3 kg/km2 month), the “free” CO2 being transported to the sea at Isbjørnhamna Bay (40.4 kg/km2 month). In contrast, the water flowing through acidic rocks are rich in “free” CO2. The concentrations of dissolved and transported HCO3 – ionsfrom the polar catchments are closely correlated with variations in the daily production of biogenic CO2