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    An Assement of the Relationship between Glacier Mass Balance and Synoptic Climate in Norway: Likely future implications of climate change.


    Fealy, Rowan (2004) An Assement of the Relationship between Glacier Mass Balance and Synoptic Climate in Norway: Likely future implications of climate change. PhD thesis, National University of Ireland Maynooth.

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    Abstract

    Regional variations in temperature and precipitation from selected European stations are found to be significantly related to large-scale modes of atmospheric variability in the North Atlantic. Increased westerlies over Europe, particularly since the 1970s, are shown to significantly contribute to increases in temperature and precipitation over northern Europe while suppressing the penetration of warm, moist air into more southern European locations. These regional variations, primarily resulting from changes in the atmospheric circulation, are found to largely explain the divergent response evident in glacier mass balance, between Scandinavia and the Alps, over the last 30 years.To further examine these linkages, a Temporal Synoptic Index(TSI) was derived for a number of locations in Norway. Principal Components Analysis (PCA) and subsequent clustering of component scores is used to classify days for both winter and summer seasons over the period 1968-1997. Findings indicate that the occurance of 'warm' type air masses during the summer months have increased in frequency, particularly since the late 1980s. However, temperatures were also found to be decreasing in these clusters. A general decrease in the frequency of 'cold' cluster types during the winter months is evident until the early 1990s. These decreases were largely compensated for by increases in the frequency of 'warm' types, with an increased moisture carrying capacity,particularly since the late 1970s. The frequency occurence of these key air mass types was shown to be significantly related to glacier mass balance during both the accumulation and ablation season. Winter air mass types from maritime source regions act to enhance accumulation and suppress ablation, while summer continental source types suppress accumulation and enhance ablation. Statistically downscale output from the HadCM3 GCM for two locations in southern Norway indicate mean winter temperatures are likely to increase by -1.25°C by the end of the present century with the largest increases occurring during December and January. Summer increase are suggested to be in the region of -2.5°C, with a more marked increase of up to -3.5°C during the month of August. Based on these scenarios, a Temporal Synoptic Index for the period 1997-2099 is constructed. This index is then used to predict glacier mass balance, used as input into an ice-flow model for Rembesdalskaka, in southern Norway, to access likely future changes in glacier behaviour as a consequence of anthropogenic climate change. Results for the ice-flow model indicate that the equilibrium line altitude (ELA) of Rembesdalskaka is likely to increase in altitude from its average 1968-1997 position of 1650 metres to 1750 metres by end of century resulting in a retreat of front position of nearly 3km. Despite a decreasing glacier net balance which commences around 2010,increases in summer ablation only become a siqnificant contributor to net balance after 2040, resulting in an advance of the glacier front of up to 1km during the first few decades of the century. These findings suggest that the hydroelectric power industry in Norway is likely to be beneficiary of the projected changes in glacier behaviour arising from climate change.

    Item Type: Thesis (PhD)
    Keywords: Glacier Mass Balance; Synoptic Climate;
    Academic Unit: Faculty of Social Sciences > Geography
    Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
    Item ID: 5323
    Depositing User: IR eTheses
    Date Deposited: 15 Aug 2014 14:45
    URI:

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