Carto Shannon L, Weaver Andrew J, Hetherington Renée, Lam Yin, Wiebe Edward C
School of Earth and Ocean Sciences, University of Victoria, PO Box 3055, Victoria, BC, V8W 3P6, Canada.
J Hum Evol. 2009 Feb;56(2):139-51. doi: 10.1016/j.jhevol.2008.09.004. Epub 2008 Nov 18.
The results from two climate model simulations are used to explore the relationship between North Atlantic sea surface temperatures and the development of African aridity around 100,000 years ago. Through the use of illustrative simulations with an Earth System Climate Model, it is shown that freshwater fluxes associated with ice sheet surges into the North Atlantic, known as Heinrich events, lead to the southward shift of the intertropical convergence zone over Africa. This, combined with the overall increased aridity in the cooler mean climate, leads to substantial changes in simulated African vegetation cover, particularly in the Sahel. We suggest that Heinrich events, which occurred episodically throughout the last glacial cycle, led to abrupt changes in climate that may have rendered large parts of North, East, and West Africa unsuitable for hominin occupation, thus compelling early Homo sapiens to migrate out of Africa.
利用两个气候模型模拟的结果来探究约10万年前北大西洋海表温度与非洲干旱化发展之间的关系。通过使用地球系统气候模型进行说明性模拟，结果表明，与冰盖涌入北大西洋相关的淡水通量（即所谓的海因里希事件）导致非洲热带辐合带向南移动。这与较冷平均气候中整体干旱加剧相结合，导致模拟的非洲植被覆盖发生显著变化，特别是在萨赫勒地区。我们认为，在整个末次冰期循环中 episodically 发生的海因里希事件导致了气候的突然变化，这可能使北非、东非和西非的大片地区不适宜古人类居住，从而迫使早期智人迁出非洲。 （注：episodically 这个词不太明确准确意思，可能是“周期性地”之类，这里按原样保留未翻译准确）
