| Summary: | During the Quaternary period, the climate has been dominated by glacial cycles resulting in periodic ice sheet coverage over Scandinavia and Sweden. In the scenarios for future climate development used in the assessment of long-term safety for planned repository of spent nuclear fuel, the possibility of future glaciations need to be considered. The present study is part of a larger hydrological study, GRASP, in which the hydrology of a lake (Two Boat Lake) located close to the Greenland ice sheet and its catchment, water balance and lake level has been studied. The purpose of the present study is to test the hypothesis if changes in the amount of snow on the lake ice surface can explain observed changes in lake level during winters. The results from comparisons between lake pressure data and data on precipitation and wind speed show that there is a relationship between pressure and meteorological events. For selected periods investigated in more detail, it was seen that during events when the wind speed exceeded the value for snow erosion, the pressure in the lake often decreased, and during periods dominated by large amounts of precipitation the pressure increased. Scatterplots of cumulative precipitation and water pressure in the lake indicate that there is a relationship between the two parameters. However, bivariate linear regression analyses of the individual winter periods did, in general, not show a clear relationship between pressure and cumulative precipitation. Since the pressure is influenced also by other parameters than precipitation, such as wind and sublimation, other statistical methods, such as multivariate regression, may shed more light on the relationship between pressure and meteorological parameters. Nevertheless, the overall results show that the investigated, largest, pressure variation during winter in many cases can be explained by meteorological events, and therefore do not reflect changes in lake water level. The results of the investigations in Greenland, with the increased knowledge ...
|
|---|