Abstract ID: 3.14046 | Accepted as Talk | Talk | TBA | TBA

The mountainous regions are perceived as significant climate “hotspots,” capable of intensifying climatic changes observed in other areas. The principle of elevation-dependent warming (EDW), which indicates that warming rates differ based on elevation, is widely recognized. Several studies show that temperature trends at mountain locations can be significantly different from those at nearby low-elevations. EDW may arise from various mechanisms, including changes in snow albedo and surface-based feedbacks, changes in water vapour–radiative feedbacks, changes in the cloud feedback and aerosol loading changes. Some factors will be more influential than others in certain parts of the world and at certain times of the year, and this may partly account for the differences in EDW. Investigations into EDW based on historical data are notably absent in high-latitude regions, including the Norwegian mountains. While extensive analyses have been conducted on comprehensive datasets primarily from lowland and coastal areas in Norway, the long-term temperature trends and variability within the mountainous regions of Norway have yet to be thoroughly examined, despite the country’s predominantly mountainous terrain. Meteorological observations in the Norwegian mountains were established in the early 20th century along the Bergen and Dovre railways, and two high mountain observatories were established in the 1930s. A number of new weather stations have been established in the mountains in Norway over the past 30 years. This research seeks to establish homogeneous temperature reference series for the mountainous regions of Norway, utilizing a unique dataset obtained from mountain weather stations. Furthermore, the study investigates long-term trends and variability in air temperature derived from both observational data and gridded datasets, particularly in relation to the lowland areas. In terms of future climate, some multi-model ensemble projections for the 21st century in northern Europe suggest that the strongest warming is estimated for high elevations in Scandinavia. On the other hand, other studies using statistical downscaling of temperature indicate increased warming at valley stations compared to neighbouring mountain stations, particularly in winter. We discuss potential processes that may be driving EDW in Norway and thus influence the future projections in different ways.