Arctic and Snow Hydrology

In recent years the Arctic has received much attention from hydrologists and scientists from other disciplines. Most climate models predict that the largest warming due to the well-known enhanced greenhouse effect will occur at northern high latitudes, particularly in winter. Higher water vapour concentrations in the atmosphere will also lead to an increase in precipitation, especially over northern mid- to high latitudes (IPCC, 2001; 2007). Since Arctic and sub-Arctic environments are dominated by cryospheric phenomena, such as snow cover and frozen soils, it is generally believed these areas are highly sensitive to a higher temperature or precipitation. The presence of snow, for example, controls the length of the growing season for plants and lichens, as well as the thermal regime and moisture conditions of the soil (Koster, 1991). However, changes in the hydrological system of high latitude regions may not only have important consequences for the entire Arctic ecosystem, but also have the potential to feed back to the regional or even global climate. Since snow has a very high albedo, which controls the fraction of incident solar radiation that is reflected, a change in the snow cover extent on the Northern Hemisphere will influence the global radiation budget (Anisimov & Fitzharris, 2001). And as some of the largest rivers in the world drain into the Arctic Ocean, a change in the discharge regime of Arctic rivers may affect the formation of sea ice and the freswhater export to the North Atlantic, which plays a role on the thermohaline circulation that is responsible for the relatively mild climate in Western Europe (Lewis et al., 2000). Because of this key role of the Arctic in the global climate and hydrological system, it is important to understand the relevant hydrological processes in northern environments. The aim of this chapter is to discuss the special features of Arctic and sub-Arctic environments and to describe the most important Arctic hydrological processes: snow accumulation and melt, the influence of frozen soils and permafrost on surface and groundwater hydrology, and typical Arctic river discharge regimes. To conclude, we will look into the potential effects of a change in climate on the Arctic hydrological cycle.

DANKERS Rutger; 

2013-02-21

IAHS Press

JRC50646

978-1-901502-54-1,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC50646,