On the response of the oceanic wind-driven circulation to atmospheric CO2 increase
On the response of the oceanic wind-driven circulation to atmospheric CO2 increase
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DOI：
10.1007/s00382-005-0032-5
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发表时间：
2005-07
期刊：
影响因子：
4.6
通讯作者：
O. Saenko;J. Fyfe;M. England
中科院分区：
文献类型：
--
作者：
O. Saenko;J. Fyfe;M. England
一个全球性的，通量校正的气候模式被用来预测地面风应力和相关的风驱动的海洋环流的气候状态对应于一个简单的每年1%的CO2增加的情况下，大气CO2浓度的两倍和四倍。模式表明，随着CO2浓度的增加，南半球中纬度地区的零风应力旋度位置向北移动。此外，在南半球中纬度地区，风应力显著增强。结果，南大洋副极地纬向翻转环流圈的水循环速率增加了约6Sv（1 Sv=106m3s−1），CO2增加一倍，CO2增加四倍，增加12 Sv，这意味着绕极流南部的深水上涌增加，其北部的Ekman泵送增加。此外，风应力和风应力旋度的变化转化为水平物质输送的变化，导致南北半球副热带环流向极扩展，南极绕极流加强。最后，南大洋近地面风的增强导致了对海洋环流的机械能供应大幅增加。
A global, flux-corrected climate model is employed to predict the surface wind stress and associated wind-driven oceanic circulation for climate states corresponding to a doubling and quadrupling of the atmospheric CO2concentration in a simple 1% per year CO2increase scenario. The model indicates that in response to CO2increase, the position of zero wind stress curl in the mid-latitudes of the Southern Hemisphere shifts poleward. In addition, the wind stress intensifies significantly in the mid-latitudes of the Southern Hemisphere. As a result, the rate of water circulation in the subpolar meridional overturning cell in the Southern Ocean increases by about 6 Sv (1 Sv=106m3s−1) for doubled CO2and by 12 Sv for quadrupled CO2, implying an increase of deep water upwelling south of the circumpolar flow and an increase of Ekman pumping north of it. In addition, the changes in the wind stress and wind stress curl translate into changes in the horizontal mass transport, leading to a poleward expansion of the subtropical gyres in both hemispheres, and to strengthening of the Antarctic Circumpolar Current. Finally, the intensified near-surface winds over the Southern Ocean result in a substantial increase of mechanical energy supply to the ocean general circulation.