Similarities and differences in the response to climate warming of two ice caps in Iceland
Similarities and differences in the response to climate warming of two ice caps in Iceland
复制标题
冰岛两个冰盖对气候变暖响应的异同
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
O. Sigurðsson
中科院分区：
文献类型：
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作者：
S. Guðmundsson;H. Björnsson;T. Jóhannesson;G. Aðalgeirsdóttir;F. Pálsson;O. Sigurðsson
采用垂直积分冰流模式和度日质量平衡模式，模拟了冰岛中部高地两个冰帽对预计气候变化的瞬时响应。朗约库尔冰帽和霍夫斯约库尔冰帽的大小相似(面积∼900km2，体积 200km2)，相距仅30 公里。气候变化模拟是从1990年开始的，从对应于1981-2000年平均气候的稳定状态开始，直到2005年为止都是由观测到的天气参数驱动的。此后，强迫是根据基于气专委B2排放情景的北欧气候变化情景进行的。1990-2005年期间的模拟与物质平衡和冰川范围的观测结果相当吻合。预计在接下来的100到200年里，这两个冰帽基本上都会消失。在接下来的150年内消失的朗约库尔，比海拔更高的霍夫斯约库尔显示出更大的质量平衡对气候变暖的敏感性，那里最高峰上的冰可能会持续200多年。与1981-2000年平均值相比，模拟径流增加的很大一部分已经发生在1990-2005年期间。径流在未来40-60年内将进一步增加，并将保持在相当高的水平，直到21世纪末。
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, Langjokull and Hofsjokull, are of similar size (area ∼900 km2 and volume ∼200 km3) and located only ∼30 km 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. Langjokull, which disappears within the next 150 years, shows larger mass-balance sensitivity to warming than the higher elevated Hofsjokull, 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.