The parameterisation of Mediterranean–Atlantic water exchange in the Hadley Centre model HadCM3, and its effect on modelled North Atlantic climate
The parameterisation of Mediterranean–Atlantic water exchange in the Hadley Centre model HadCM3, and its effect on modelled North Atlantic climate
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哈德利中心模型 HadCM3 中地中海-大西洋水交换的参数化及其对模拟北大西洋气候的影响
DOI：
10.1016/j.ocemod.2012.11.002
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发表时间：
2013
期刊：
影响因子：
3.2
通讯作者：
M. Gutjahr
中科院分区：
文献类型：
--
作者：
R. Ivanović;P. Valdes;R. Flecker;L. Gregoire;M. Gutjahr
多个古代理和模拟研究表明，地中海外流水（MOW）是大西洋经向翻转环流（AMOC）的重要驱动力，特别是在弱翻转期间。在这里，我们采用HadCM 3海洋大气环流模式（GCM），调查使用不同的参数化的地中海-大西洋水交换对全球海洋环流和气候的影响。在HadCM 3中，模拟通过直布罗陀海峡的流动时，采用“开放式航道”而不是“扩散管”，导致MOW羽流变浅并加强。这重新组织了大西洋浅层环流，产生了高达+11 °C和-7.5 °C的区域地表气温异常。我们的结论是，当调查MOW对模拟海洋环流和气候的影响时，准确的参数化地中海-大西洋交换是重要的，应该与观测到的淡水和盐度通量约束相匹配。这可能无法通过一个简单的“扩散管”与深度不变的混合系数。
Multiple palaeo-proxy and modelling studies suggest that Mediterranean Outflow Water (MOW) is an important driver of Atlantic Meridional Overturning Circulation (AMOC), particularly during periods of weak overturning. Here, we employ the HadCM3 ocean–atmosphere General Circulation Model (GCM) to investigate the effect of using different parameterisations of Mediterranean–Atlantic water exchange on global ocean circulation and climate. In HadCM3, simulating flow through the Gibraltar Straits with an ‘open seaway’ rather than a ‘diffusive pipe’ causes a shoaling and strengthening of the MOW plume. This reorganises shallow Atlantic circulation, producing regional surface air temperature anomalies of up to+11°C and −7.5°C. We conclude that when investigating the influence of MOW on modelled ocean circulation and climate, an accurate parameterisation of Mediterranean–Atlantic exchange is important and should match observed fresh water and salinity flux constraints. This probably cannot be achieved through a simple ‘diffusive pipe’ with depth invariant mixing coefficient.