Similarities and differences in the response to climate warming of two ice caps in Iceland.

Autor: Guðmundsson, S.1 sg@hi.is, Björnsson, H.1, Jóhannesson, T.2, Aðalgeirsdóttir, G.3, Pálsson, F.1, Sigurðsson, O.2
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Zdroj: Hydrology Research. 2009, Vol. 40 Issue 5, p495-502. 8p.
Abstrakt: The transient response to projected climate change of two ice caps in the central Icelandic highland was simulated with a vertically integrated ice-flow model coupled to a degree-day mass- balance model. The ice caps, Langjökull and Hofsjökull, are of similar size (area ~ 900 km2 and volume ~200km3) and located only --30km apart. The climate change simulations were started in 1990 from steady states corresponding to the average climate of 1981-2000 and driven with observed weather parameters until 2005. Thereafter, the forcing was according to a Nordic climate change scenario based on the IPCC B2 emission scenario. The simulations during the period 1990-2005 compare reasonably well with observations of mass-balance and glacier extent. Both ice caps are projected to essentially disappear during the next 100 to 200 years. Langjökull, which disappears within the next 150 years, shows larger mass-balance sensitivity to warming than the higher elevated Hofsjökull, where ice on the highest peaks may last over 200 years. A large proportion of the simulated runoff increase with respect to a 1981-2000 average has already taken place within the period 1990-2005. The runoff will increase further during the next 40-60 years and remain considerably higher than at present until the end of the 21st century. [ABSTRACT FROM AUTHOR]
Databáze: GreenFILE