Testing concepts for continuous monitoring of the meridional overturning circulation in the South Atlantic
Testing concepts for continuous monitoring of the meridional overturning circulation in the South Atlantic
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DOI：
10.1016/j.ocemod.2009.03.005
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发表时间：
2009-01-01
期刊：
影响因子：
3.2
通讯作者：
Marotzke, Jochem
中科院分区：
文献类型：
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作者：
Baehr, Johanna;Stroup, Adrianne;Marotzke, Jochem
我们研究了在大西洋北纬 26 度实施的经向翻转环流 (MOC) 监测策略是否以及如何也适用于南大西洋的某个纬度。监测 MOC 的 RAPID 26 度 N 策略基于对整个纬向样带的纬向密度差的连续测量、对西边界流的连续测量以及卫星观测对纬向风应力的额外估计。在这里，我们在全球耦合气候 ECHAM5/MPI-OM 中模拟了类似于北纬 26 度的 RAPID 阵列的监测阵列，强制使用 IPCC 情景 All B。我们发现监测策略可以提供南大西洋 MOC 的可靠估计，但需要仔细选择纬度，以确保充分覆盖来自北方和南方的变化。北大西洋的限制也适用于南大西洋，但是，我们发现直接边界流观测和底部速度测量对于时间平均值和变异性的重要性不如北大西洋。然而，西边界观测和底部速度测量对于正确捕获 MOC 的垂直结构至关重要。我们建议仅在边界水流不触及陡峭地形且底部速度较小的地方进行基于 26 度 RAPID 策略的全流域 MOC 监测。 (C) 2009 Elsevier Ltd. 保留所有权利。
We investigate if and how the monitoring strategy for the meridional overturning circulation (MOC) implemented at 26 degrees N in the Atlantic can also be applied at a latitude in the South Atlantic. The RAPID 26 degrees N strategy to monitor the MOC is based on continuous measurements of zonal density differences across a zonal transect, continuous measurements of the western boundary current, and additional estimates of the zonal wind stress from satellite observations. Here, we simulate a monitoring array akin to the RAPID array at 26 degrees N in the global coupled climate ECHAM5/MPI-OM, forced with the IPCC scenario All B. We find that the monitoring strategy can provide reliable estimates of the MOC in the South Atlantic, but the latitude needs to be carefully chosen to ensure adequate coverage of the variability arriving from both the north and the south. The limitations in the North Atlantic apply in the South Atlantic, however, we find that direct boundary current observations and bottom velocity measurements are of lesser importance for the time-mean value and the variability than in the North Atlantic. However, western boundary observations and bottom velocity measurements are crucial in capturing the vertical structure of the MOC correctly. We suggest that basin-wide MOC monitoring based on the RAPID strategy at 26 degrees N be conducted only where boundary Currents do not hit steep topography, and where bottom velocities are small. (C) 2009 Elsevier Ltd. All rights reserved.