Is realistic Antarctic sea-ice extent in climate models the result of excessive ice drift?
Is realistic Antarctic sea-ice extent in climate models the result of excessive ice drift?
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DOI：
10.1016/j.ocemod.2014.04.004
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发表时间：
2014-05
期刊：
影响因子：
3.2
通讯作者：
P. Uotila;P. Holland;T. Vihma;S. Marsland;N. Kimura
中科院分区：
文献类型：
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作者：
P. Uotila;P. Holland;T. Vihma;S. Marsland;N. Kimura
我们首次计算了一个完全耦合的气候模式——澳大利亚ACCESS模式的海冰浓度收支，以评估其在模拟南极海冰秋冬演变方面的现实性。海冰浓度收支由局地变化、平流和辐散组成，剩余分量代表热力学和脊化的净效应。虽然该模式较好地模拟了海冰面积的演变，但其海冰浓度收支与观测值存在较大偏差。模拟的海冰收支分量偏离南极海岸附近的观测值，在南极海岸，模拟的冰运动更收敛，而在冰边缘附近，由于冰速度之间的不一致，模拟的冰平流速度比观测到的要快。在中心冰原，模式和观测值之间的一致性较好。基于此，我们建议在模拟观测到的南极海冰趋势时，应着重提高模拟冰漂的真实感。
For the first time, we compute the sea-ice concentration budget of a fully coupled climate model, the Australian ACCESS model, in order to assess its realism in simulating the autumn–winter evolution of Antarctic sea ice. The sea-ice concentration budget consists of the local change, advection and divergence, and the residual component which represents the net effect of thermodynamics and ridging. Although the model simulates the evolution of sea-ice area reasonably well, its sea-ice concentration budget significantly deviates from the observed one. The modelled sea-ice budget components deviate from observed close to the Antarctic coast, where the modelled ice motion is more convergent, and near the ice edge, where the modelled ice is advected faster than observed due to inconsistencies between ice velocities. In the central ice pack the agreement between the model and observations is better. Based on this, we propose that efforts to simulate the observed Antarctic sea-ice trends should focus on improving the realism of modelled ice drift.