How is the warming climate in the North Atlantic reflected in stable isotopes of precipitation in Iceland?

In this presentation, stable water isotopes in precipitation will be used to better understand the hydrological and atmospheric processes within the water cycle. Special emphasis will be put on studies of the deuterium excess, as it is expected to reflect conditions at the original evaporation site at the surface of the ocean.

 

For the last 9 years daily precipitation in Reykjavík has been collected as a part of an international study of the physical processes of the atmospheric hydrological cycle in the North Atlantic. We will link this almost continuous isotope-dataset to climate parameters. We will also review the long-term monthly precipitation available from North and SW Iceland, collected by the Met office since 1983 and measured for stable isotopes at the Science Institute, University of Iceland, in connection with the warming climate, reflected both in the shrinkage of Icelandic glaciers and warming seas around Iceland.

 

In 1962 the first mass-spectrometer was taken into use in Iceland. It was solely used for hydrogen isotope analyses of water and glacier ice. Hydrogen isotope data on surface and groundwater was used to construct contour map of the mean annual precipitation in Iceland (Árnason, 1976). The contour map has been used extensively to trace the origin of geothermal waters in Iceland and to map the regional directions of groundwater flow. We will use this historical dataset as a reference for possible changes in the water cycle during the last 50 years.

 

Reference

Árnason, B. 1976. Groundwater systems in Iceland traced by deuterium. Vísindafélag Íslendinga. Rit 42, 236 bls.