Towards the development of long-term winter records for the Snowy Mountains

Abstract

Alpine regions are highly sensitive to climate change and its resultant impacts on ecosystems and human activity. Small changes in temperature and precipitation in these regions can have large effects on ecosystems while changes in snow cover could affect the viability of the ski industry in some regions. Long-term datasets of temperature, precipitation and snow depth in these regions are therefore important in identifying whether any climate change signal is in fact evident. This paper investigates a method for developing long-term winter records of temperature, precipitation and seasonal snow depth from available climate data in the Kosciuzsko National Park region using linear regression techniques and draws inferences from these records with respect to historical trends. The imputed winter snow depth dataset indicates that although extreme heavy snow events may not have changed over the record, the average snow depths around the turn of the 20th century appear to have been between five per cent and 14 per cent higher than the 1961–1990 average while in the last decade they have dropped by around 15 per cent. This reduction in snow depths supports the expected impacts of global warming on the Australian alpine region and highlights the impacts on the ecosystems and human activity that may be occurring in this sensitive climatic region. This analysis also indicates that the signal from global warming has become a significant factor in both the temperature and snow records after around 1985 as well as identifying issues with regard to the use of the automatic weather stations (AWS) rainfall data from Cabramurra post-1997 in climate analysis.