This thesis aims to analyse precipitation gauge data in the glaciated Rofental to further understanding of the temporal and spatial trends that have occurred over the last sixty years, evaluate a wind-blown snow undercatch correction scheme for relatively recently installed weighing gauges in the upper part of the catchment and investigate the drivers of extreme precipitation days and months in the region.
It is found that monthly and seasonal variability in precipitation totals has increased since the 1960s, with a general increase in winter precipitation and a, statistically insignificant, decrease for spring and summer. There are also notable changes in the spatial distribution of precipitation, with the mean altitudinal gradient across totalising gauges decreasing for all seasons, most significantly in winter where a negative gradient was found for a number of seasons in the early 2010s. This is shown to have possible links to synoptic changes between the 1980s and present day.
A wind-blown correction scheme using temperature and wind speed data, developed by Sevruk and implemented by Kochendorfer et al., is implemented for weighing gauges, and shows significant improvements in precipitation undercatch relative to both sonic snow depth measurements and adjusted glacier mass balance values for glaciological winter. The increasing number of sites with such gauges co-located with weather stations and anemometers provides an opportunity for further evaluation and implementation of this scheme to enhance precipitation recording at high altitude.
It is also found that the relationship between the North Atlantic Oscillation and precipitation in the Rofental has changed significantly, with NAO+ winters becoming increasingly linked with high precipitation and NAO- summers to low precipitation. This is perhaps linked to changing frequencies of Vb lows in different seasons.
Synoptic analyses of both daily and monthly extremes in precipitation find that extreme precipitation are generally linked with upper lows across northwest Europe, and drier spells with blocking, while extremes of altitudinal gradient across the Rofental are connected to Scandinavian blocks or troughs.
Different stations within the Rofental are also found to have markedly different characteristics in rainfall distribution, with Vernagtbrücke’s wettest days generally being associated with a more northerly flow, Martin-Busch-Hutte being more associated with southerly and Vent with precipitation moving westwards down the main Alpine valleys.