Klimatrender i Jotunheimen: En undersøkelse av variasjoner i likevektslinja i dag og under Lille istid ved hjelp av fjernanalyse og ARR-metoden

Abstract

A large scale trend analysis of climatic variations in Jotunheimen, southern Norway based onglacier variations was carried out. Equilibrium line altitudes (ELAs) were estimated for 92 glaciers for present day and Little Ice Age (LIA) conditions by use of remote sensing and the accumulation area ratio method (AAR). A steady-state AAR value of 0.6 and glacier length was used. Results show a marked continental gradient where ELAs rise and changes in ELA (ΔELA) decrease from west to east both for present day and Little Ice Age conditions emphasizing the importance of temperature and precipitation distribution through the study area. Glacier size indicates no geographic trend. Glaciers with ELAs at high altitudes have generally experienced less reduction in length and at the equilibrium line. Glacier orientation shows a preferred north, northeast aspect which is also true for glacier distribution with a higher number of glaciers in north, northeast and easterly slopes. Glacier form, size, hypsometry and other local topographic factors all influence the climatic trend in various ways, but for a large scale trend analysis these effects are of less importance.