African rainfall variability: Palaeo insights into the climate history of our hominid ancestors and the monsoon response to a warmer future

季风降水控制着世界上10亿多最贫困人口的生活。萨赫勒地区的情况非常严重，那里的年降雨量异常多变。在世纪后期，该地区遭受了灾难性的干旱，降水量下降了约40%，造成了毁灭性的影响，正如Live Aid所强调的那样。在地质时间尺度上，降雨量的变化甚至更为极端。有时，撒哈拉沙漠地区是一个植被覆盖的景观，被居住着河马的广阔湖泊和河流横切。在其他地方，沙漠远远超出了目前的界限。过去降雨量的这些戏剧性变化在我们原始人类祖先的多样化和迁移模式中扮演了什么角色？我们可以从古记录中学到什么来帮助预测该地区降雨对未来几个世纪变暖的反应？对未来气候的模式预测存在分歧。为了解决这些问题，我们需要（i）大陆水文气候和（ii）非洲季风的水分来源：大西洋和印度洋的变化的日期明确的记录。您将利用大洋钻探计划（ODP）海洋钻探岩心来测试陆地-海洋-大气遥相关的竞争性假设，重点关注已知温暖和/或原始人周转/迁移的战略性过去间隔。

Monsoon precipitation controls the lives of over one billion of the world's poorest people. The situation is acute in the Sahel where annual rainfall is exceptionally variable. In the late 20th century the region suffered catastrophic drought in which precipitation declined by ~40%, with devastating effects as highlighted by Live Aid. Changes in rainfall over geological timescales were even more extreme. At times the Sahara Desert region was a vegetated landscape cross-cut by vast lakes and rivers inhabited by hippopotamuses. At others the desert extended well beyond present limits. What role did these dramatic past changes in rainfall play in the diversification and migration patterns of our hominid ancestors? What lessons can we learn from the palaeo-record to help predict the response of rainfall in the region to warming over coming centuries? Model predictions of future climate diverge. To address these questions we need well-dated records of change in both (i) continental hydroclimate and (ii) the moistures sources for the African monsoons: the Atlantic and Indian Oceans. You will exploit Ocean Drilling Program (ODP) marine drill-cores to test competing hypotheses of the land-ocean-atmospheric teleconnections involved by focusing on strategic past intervals of known warmth and/or hominid turnover/migration.