Hydrologic impacts of past shifts of Earth's thermal equator offer insight into those to be produced by fossil fuel CO2
Hydrologic impacts of past shifts of Earth's thermal equator offer insight into those to be produced by fossil fuel CO2
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DOI：
10.1073/pnas.1301855110
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发表时间：
2013-10-15
影响因子：
11.1
通讯作者：
Putnam, Aaron E.
中科院分区：
文献类型：
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作者：
Broecker, Wallace S.;Putnam, Aaron E.
全球降雨模式的重大变化伴随着14.6 kya气候突变开始时地球热赤道向北移动。地球风雨带向北的拉力源于北大西洋冬季海冰的融化，导致半球间经向温度梯度变陡。地球热赤道向南迁移可能伴随着北半球最近的中世纪温暖期到小冰期的气候转变。随着化石燃料二氧化碳使地球变暖，北半球大陆的变暖速度预计将快于南半球海洋。因此，我们预测，由半球间温差增加引发的地球热赤道向北移动，很可能会产生与过去北半球温暖时期发生的水文变化类似的变化。如果是这样，美国西部、中东和亚马逊南部将变得更加干燥，而季风亚洲、委内瑞拉和赤道非洲将变得更加湿润。应获取额外的古气候数据并进行模型模拟以评估该模拟的可靠性。
Major changes in global rainfall patterns accompanied a northward shift of Earth's thermal equator at the onset of an abrupt climate change 14.6 kya. This northward pull of Earth's wind and rain belts stemmed from disintegration of North Atlantic winter sea ice cover, which steepened the interhemispheric meridional temperature gradient. A southward migration of Earth's thermal equator may have accompanied the more recent Medieval Warm to Little Ice Age climate transition in the Northern Hemisphere. As fossil fuel CO2 warms the planet, the continents of the Northern Hemisphere are expected to warm faster than the Southern Hemisphere oceans. Therefore, we predict that a northward shift of Earth's thermal equator, initiated by an increased interhemispheric temperature contrast, may well produce hydrologic changes similar to those that occurred during past Northern Hemisphere warm periods. If so, the American West, the Middle East, and southern Amazonia will become drier, and monsoonal Asia, Venezuela, and equatorial Africa will become wetter. Additional paleoclimate data should be acquired and model simulations should be conducted to evaluate the reliability of this analog.