• Keine Ergebnisse gefunden

ounts was 50cms and between the huts of Kinnvika, huge snow hills were formed with a height of up to 5m.

During April and May 2003, with the influence of sunshine, heavy winds and temperatures between -5°C and -10°C it was observed that many snow hills were covered by a 2-5mm thick ice layer, shining in the sun like a glacier.

From March to May 2003 sometimes it was observed that large, plain ice crystals with a size of up to 20mm grew on certain locations, on the snow surface. These ice crystals sparkled brightly in sunlight and showed, sometimes, various bright colours.

Until the end of May 2003 even at air temperatures of +3°C the snow didn’t really melt.

Further, the snow sublimated from it’s surface, directly into the fairly dry air, being heated by the sun. In this way, at certain areas, the snow slowly disappeared completely from the ground. In the middle of June 2003 at temperatures of around +5°C, the snow really melted, producing a huge amount of water on the surface of the ground. In mid-July 2003 most of the snow had vanished, only some snow hills remained.

Single snow flakes were caught during snowfall and investigated by microscope. It seems, that in autumn, in combination with northerly winds the snow crystals were covered with frozen micro droplets. This effect was not observable during snowfall with southerly winds.

The CO2 concentration was measured each day in the air in clear weather as well as during snowfall or rain. Besides this the CO2 content was recorded in narrow caves which were bored in densely packed snow hills.

In air the CO2 concentration was between 320 and 380 ppm. It seems, that during rain fairly low values are valid. However during snowfall with northerly winds, the CO2 content was found to rise up to 380 ppm.

The CO2 concentration measured in snow in autumn 2002, seemed to differ from those measured in spring 2003. In September and October 2002 the values recorded in the snow were up to 200 ppm higher than the corresponding values in the air 1 metre above ground.

The CO2 concentration in the snow caves seemed to depend on the temperature in the snow which were between -0.5°C and -10°C. In spring 2003 similar effects could not be observed.

7 SNOW 7.1 Observations

The first snowfall was observed 27th August 2002 on sea level close to Kinnvika. In September and October 2002 during 30 days snowfall or sleet and rain was noticed. The snowfall occurred mostly in combination with strong winds from northern directions, while the rain and drizzle was observed during southerly winds. Due to the nearly permanently strong winds the snow did not cover the ground in a thick layer. Most of the snow was blown away shortly after the snowfall. In certain positions hills of densely packed snow were form with a height of less than 1 meter.

November 2002 on 24 days and in December 2002 on 13 days, snow fell, sometime heavy blizzards. In December, rain was observed on one day. From January to April 2003 each month on about 15 days, a little amount of snow fell, in combination with blizzards.

The snow layer on the ground and the ice surface grew during these months in a minor way.

The snow layer had, at the end of April 2003, a thickness of about 30cms. However, between the huts, snow hills were formed with heights up to 3.5m. In mid-May 2003 large am snow fell, probably, in total, more than all months before. Finally the snow layer on the ice

132

0,00

CO2 in Air (below) and Snow (above), September/October 2002, Kinnvika

CO2 Observation in September and October 2002

The CO2 content is measured using an IR measuring probe (Testo 535, Germany) in the air as well in small caves (diameter 3 cms.) in the snow layer which was formed by the newly fallen

now.

he values in the air seem to vary depending on the weather situation. Particularly in the case

or

was

Snow and ice seem to act in some respect similar to a huge lung. CO2 gas above the surface of open sea water is transported by the wind and finally bound to snow crystals which are deposited as snow layers on land. During the sublimation of snow this CO2 gas is expired into the atmosphere over the land. In this way by snow clouds worldwide, a huge amount of CO2

may be transported out of the sea water and into the atmosphere. Possibly it is worthwhile to investigate this effect by further experiments and theoretical estimations.

s T

of snow fall in connection with northerly winds the values rise. It seems that the falling snow crystals exhausted some CO2 gas.

The snow crystals were investigated by microscopy under different conditions. In the case of snow fall in connection with northerly winds, the observed snow crystals were covered with frozen small water droplets. Possibly the water vapour over the open sea water north of Nordaustland, contains a high amount of CO2.

In the snow the measured CO2 values seemed to be dependent on the consistency of the snow layer. The highest values were measured in densely packed snow. Within some days these high values of CO2 decreased to those measured in the air. Besides the consistency of the snow and the time after the snow fall, the temperature in the snow seemed to be important f the CO2 concentration. It seems that preferable in the temperature range between -1°C and -5°C, the packed snow exhausted CO2.

When the snow melted in June it became very wet. Consequently the exhausted CO2

dissolved in the liquid films and was not measurable in the atmosphere. However when the snow sublimated at cold temperatures during sunshine, instead of melting, the CO2 bounded by the snow crystals became free and was clearly measurable above the surface of the snow layer.

134

-20,00

Temperatures in Snow and Air, November 2002, Kinnvika

Temperature Distribution in Snow Layers

Snow is a very good thermal insulating material. Using sensors, the temperatures were recorded during long time periods in different snow layers. The graph shows an example oncerning the temperatures in a snow layer within some days in November 2002. The snow

yer had a total thickness of 50cms. The measurements were performed in the air above the now surface and 10cms and 40cms in the snow, under the surface. It becomes obvious that e temperatures in the snow follow the air temperature, time retarded,. Besides this, the

gas , was

com

mi om

Kinnvika on Nordaustland is a region far away from any essential sources of man made CO2

emissions. Therefore it is possible to measure the variation of the CO2 content in air undisturbed by other sources. The careful investigation and understanding of the observed effects may help to describe the complex transportation processes of CO2 in the atmosphere.

Perhaps a contribution to the discussion will be possible concerning the warming up effects of the Earth due to the rising CO2 concentration in the atmosphere.

c la s th

dynamic graph of the air temperature is strongly flattened in the snow graphs.

7.2 Conclusions

It seems that snow, rain and ice have an essential influence on the concentration of CO2 in the air. This observation corresponds to the CO2 measurements in ice. Possibly in freezing water vapour forming snow crystals or small ice droplets, the content of dissolved CO2

increases strongly. It seems that this effect is much stronger when the air had the chance to interact directly with the surface of open sea water. This could explain that in early spring when all open water was covered by ice, the variation of the measured CO2 concentration only small. When open water was existing again in late May, the CO2 values rose up to 380ppm during snow fall.

After the snow flakes fell to the ground, snow layers are formed. The snow flakes were pressed and modified in the snow layers to a densely packed material whose crostructure differs from the original snow flakes. Possibly CO2 gas will be exhausted fr the snow during this process. The CO2 concentration increases in such regions in the snow layer from e.g. 350 ppm up to 530 ppm.

136

8 BACTERIA