An Assessment of the Relationship between Glacier Mass Balance and Synoptic Climate in Norway: Likely future implications of climate change.
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 i...
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| Format: | Thesis |
| Language: | English |
| Published: |
2004
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| Subjects: | |
| Online Access: | https://mural.maynoothuniversity.ie/5323/ https://mural.maynoothuniversity.ie/5323/1/Rowan_Fealy_20140623132518.pdf |
| Summary: | 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 ... |
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