Arctic climate change: observed and modelled temperature and sea-ice variability
Arctic climate change: observed and modelled temperature and sea-ice variability
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DOI：
10.1111/j.1600-0870.2004.00060.x
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发表时间：
2004-08-01
影响因子：
2
通讯作者：
Cattle, AP
中科院分区：
文献类型：
--
作者：
Johannessen, OM;Bengtsson, L;Cattle, AP
近年来北极气候系统的明显变化需要从一个世纪的角度进行评估，以评估北极对日益增加的人为温室气体强迫的反应。这里，将一组新的世纪和数十年尺度的地表气温（SAT）和海冰观测数据与ECHAM4和HadCM3耦合的大气-冰-海洋全球模型模拟结合使用，以便更好地确定和了解北极气候变化。我们发现，二十世纪两次明显的变暖事件都与海冰变化有关，这两次事件都在北极加剧。 SAT观测和模型模拟表明，过去二十年北极变暖的性质与二十世纪初的温暖期不同。强烈建议早期变暖是自然的内部气候系统变异，而最近的 SAT 变化是对人为强迫的反应。此外，据观察，在过去四分之一个世纪里，北极海冰面积减少了约 8 x 10(5) km(2) (7.4%)，2002 年 9 月夏季冰盖覆盖率创历史新低。一组模型预测被用来量化整个二十一世纪冰盖的变化，预计夏季冰盖减少幅度将大于冬季。在夏季，预计本世纪末北极将主要无海冰。
Changes apparent in the arctic climate system in recent years require evaluation in a century-scale perspective in order to assess the Arctic's response to increasing anthropogenic greenhouse-gas forcing. Here, a new set of century- and multidecadal-scale observational data of surface air temperature (SAT) and sea ice is used in combination with ECHAM4 and HadCM3 coupled atmosphere-ice-ocean global model simulations in order to better determine and understand arctic climate variability. We show that two pronounced twentieth-century warming events, both amplified in the Arctic, were linked to sea-ice variability. SAT observations and model simulations indicate that the nature of the arctic warming in the last two decades is distinct from the early twentieth-century warm period. It is suggested strongly that the earlier warming was natural internal climate-system variability, whereas the recent SAT changes are a response to anthropogenic forcing. The area of arctic sea ice is furthermore observed to have decreased similar to8 x 10(5) km(2) (7.4%) in the past quarter century, with record-low summer ice coverage in September 2002. A set of model predictions is used to quantify changes in the ice cover through the twenty-first century, with greater reductions expected in summer than winter. In summer, a predominantly sea-ice-free Arctic is predicted for the end of this century.