Meltwater stream temperature responses to air temperature and characteristics

• Main Author: Eyres, Matthew
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: glacier; glaciers; Alaska
• Online Access: http://usir.salford.ac.uk/id/eprint/38220/; http://usir.salford.ac.uk/id/eprint/38220/1/Matt%20Masters%20Final%20submit.pdf

The aim of this project is to examine the relative importance of size of glacier catchment area, air temperature, stream characteristics including distance travelled by meltwater in determining water temperature in meltwater rivers draining from Alpine Glaciers. Hood et al, (2013) suggested that percentage glacierisation was the determining influence on water temperature in streams draining large glacierisied basins in Alaska. Percentage glacierisation however is an unusual basin characteristic in that it largely depends on the location of the gauging station, and not on catchment physical properties. As meltwater temperature is influenced by incoming radiation, the length of time of exposure of meltwater is an important influencing factor on temperature. Length of time of exposure depends on fluvial characteristics, and distance between glacier portal and measurement/gauging station. This thesis examines how basin size, air temperature, radiation, melt stream length and stream characteristics contribute to meltwater in influencing these variable on meltwater temperature. The Swiss Alpine basin containing the glaciers Findelengletscher, Gornergletscher, (containing Grosser Aletschergletscher) all with temperature and discharge records in selected months (August and September) in 2007 with research from Collins where more than 10 years’ continuous records were investigated. Primary data was collected in the field in the Swiss Alps for air and water temperature and discharge, with secondary research collected by Collins used to show trends from previous years and support the results. Literature show the consistent links between climatic change and trends in rising discharge in glacier fed streams. Distance from glacier portal and surface area of meltwater rivers are important factors in influencing water temperature that are not related to percentage basin glacierisation. Water temperature is positively related to air temperature and negatively associated with river flow and it thermal capacity. Evidence of stream characteristics, glacier size and air temperature being key contributing factors influencing meltwater temperature proves that percentage glacierisation has no impact on stream temperature.