Localization of abrupt change in the North Atlantic thermohaline circulation
Localization of abrupt change in the North Atlantic thermohaline circulation
复制标题
北大西洋温盐环流突变的定位
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
D. Marshall
中科院分区：
文献类型：
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作者：
H. Johnson;D. Marshall
最近的气候模型实验以及古气候记录表明，大西洋的纬向翻转环流或“温盐环流”可能由于全球变暖而突然改变，这可能对欧洲的气候产生重大影响。我们使用一个简化重力模式来研究大西洋翻转环流对强迫变化的响应。我们发现，在十年和更高的频率的变化局限于一个单一的半球。这意味着：（a）拉布拉多海和格陵兰海浮力强迫的高频变化导致的倾覆变率将仅限于北大西洋，（B）北大西洋倾覆中任何观测到的年代际和更高频率的波动只能由北大西洋海盆本身的表面通量变化引起。这些结果表明，南大洋风强迫是不重要的北大西洋翻转的十年和较短的时间尺度。
Recent climate model experiments, as well as paleoclimate records, suggest that the meridional overturning circulation or “thermohaline circulation” in the Atlantic Ocean could change abruptly as a result of global warming, and that this could have a significant impact on European climate. We use a reduced‐gravity model to investigate the response of the Atlantic overturning circulation to changes in forcing. We find that variability at decadal and higher frequencies is confined to a single hemisphere. This implies that (a) overturning variability resulting from high frequency changes in buoyancy forcing in the Labrador and Greenland Seas will be limited to the North Atlantic, and (b) any observed decadal and higher frequency fluctuations in North Atlantic overturning can only result from changes in the surface fluxes within the North Atlantic basin itself. These results suggest that Southern Ocean wind forcing is not important for North Atlantic overturning on decadal and shorter timescales.