Response of a Coupled Ocean–Atmosphere Model to Greenland Ice Melting
Response of a Coupled Ocean–Atmosphere Model to Greenland Ice Melting
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DOI：
10.1007/s10712-011-9142-2
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发表时间：
2011-08
影响因子：
4.6
通讯作者：
D. Stammer;Neeraj Agarwal;Peter Herrmann;A. Köhl;C. Mechoso
中科院分区：
文献类型：
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作者：
D. Stammer;Neeraj Agarwal;Peter Herrmann;A. Köhl;C. Mechoso
我们研究了全球海洋-大气耦合系统对代表格陵兰冰盖融化的淡水强迫增强的瞬态响应。将大气-海洋耦合大气环流模型（CGCM）进行的长达 50 年的模拟与格陵兰岛融化的另一个相同长度的模拟进行了比较。为了强调大气-海洋耦合过程的重要性，将 CGCM 结果与使用海洋大气环流模型 (OGCM) 进行的其他两个实验的结果进行了比较。在其中一项 OGCM 实验中，规定的热、动量和淡水表面通量对应于 CGCM 的无扰动模拟；在另一个实验中，格陵兰融化被添加到淡水通量中。 CGCM 和 OGCM 对格陵兰岛融化的响应在大西洋具有相似的模式，尽管前者的海面高度异常幅度大五倍。 CGCM 同样显示出所有海洋盆地的所有状态变量都具有更强的变异性，因为格陵兰岛融化的影响会通过大气桥迅速传达到所有海洋盆地。我们的结论是，全球气候对格陵兰冰融化的反应高度依赖于大气-海洋耦合过程。这些导致进入大气的潜热通量减少，并导致进入海洋的净淡水通量增加，特别是在北大西洋副极地。综合结果是耦合系统对格陵兰冰盖融化有更强的响应。
We investigate the transient response of the global coupled ocean–atmosphere system to enhanced freshwater forcing representative of melting of the Greenland ice sheets. A 50-year long simulation by a coupled atmosphere–ocean general circulation model (CGCM) is compared with another of the same length in which Greenland melting is prescribed. To highlight the importance of coupled atmosphere–ocean processes, the CGCM results are compared with those of two other experiments carried out with the oceanic general circulation model (OGCM). In one of these OGCM experiments, the prescribed surface fluxes of heat, momentum and freshwater correspond to the unperturbed simulation by the CGCM; in the other experiment, Greenland melting is added to the freshwater flux. The responses by the CGCM and OGCM to the Greenland melting have similar patterns in the Atlantic, albeit the former having five times larger amplitudes in sea surface height anomalies. The CGCM shows likewise stronger variability in all state variables in all ocean basins because the impact of Greenland melting is quickly communicated to all ocean basins via atmospheric bridges. We conclude that the response of the global climate to Greenland ice melting is highly dependent on coupled atmosphere–ocean processes. These lead to reduced latent heat flux into the atmosphere and an associated increase in net freshwater flux into the ocean, especially in the subpolar North Atlantic. The combined result is a stronger response of the coupled system to Greenland ice sheet melting.