Reversed Holocene temperature-moisture relationship in the Horn of Africa.
Reversed Holocene temperature-moisture relationship in the Horn of Africa.
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DOI：
10.1038/s41586-023-06272-5
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发表时间：
2023-08
期刊：
影响因子：
64.8
通讯作者：
Sinninghe Damste, J. S.
中科院分区：
文献类型：
--
作者：
Baxter, A. J.;Verschuren, D.;Peterse, F.;Miralles, D. G.;Martin-Jones, C. M.;Maitituerdi, A.;van der Meeren, T.;Van Daele, M.;Lane, C. S.;Haug, G. H.;Olago, D. O.;Sinninghe Damste, J. S.
预计人为气候变化将严重影响全球水文循环，特别是在农业经济依赖季风降雨的热带地区。在非洲之角，近几十年来更加频繁的干旱与气候模型预测降水量随着气温上升而增加形成鲜明对比。在这里，我们使用查拉湖（肯尼亚和坦桑尼亚）沉积物记录中的有机地球化学气候代理数据来探讨大约过去 75,000 年中水文气候与温度之间联系的稳定性，从而涵盖足够广泛的温度范围来测试时域中人为气候变化的“干变得更干，湿变得更湿”范式。我们发现，在较冷的末次冰期期间，非洲最东部的有效水分与温度之间的正相关关系在 11,700 年前的全新世开始时转变为负相关关系，当时大气二氧化碳浓度超过百万分之 250，年平均温度接近现代值。因此，此时季风降水与大陆蒸发之间的收支越过临界点，温度对蒸发的正向影响大于其对降水的正向影响。我们的结果表明，在持续的人为变暖的情况下，非洲之角可能会进一步干燥，并且强调需要改进对热带水文循环中动力和热力学过程的模拟。气候代理数据表明，在非洲之角的末次冰期期间，较高的气温与较大的水分供应有关，而在当前的间冰期以及历史上，较高的气温与干旱加剧有关。
Anthropogenic climate change is predicted to severely impact the global hydrological cycle, particularly in tropical regions where agriculture-based economies depend on monsoon rainfall. In the Horn of Africa, more frequent drought conditions in recent decades contrast with climate models projecting precipitation to increase with rising temperature. Here we use organic geochemical climate-proxy data from the sediment record of Lake Chala (Kenya and Tanzania) to probe the stability of the link between hydroclimate and temperature over approximately the past 75,000 years, hence encompassing a sufficiently wide range of temperatures to test the ‘dry gets drier, wet gets wetter’ paradigm of anthropogenic climate change in the time domain. We show that the positive relationship between effective moisture and temperature in easternmost Africa during the cooler last glacial period shifted to negative around the onset of the Holocene 11,700 years ago, when the atmospheric carbon dioxide concentration exceeded 250 parts per million and mean annual temperature approached modern-day values. Thus, at that time, the budget between monsoonal precipitation and continental evaporation crossed a tipping point such that the positive influence of temperature on evaporation became greater than its positive influence on precipitation. Our results imply that under continued anthropogenic warming, the Horn of Africa will probably experience further drying, and they highlight the need for improved simulation of both dynamic and thermodynamic processes in the tropical hydrological cycle. Climate-proxy data indicate that during the last glacial period in the Horn of Africa higher temperatures were associated with greater moisture availability, whereas during the current interglacial period, as well as historically, higher temperatures have been associated with increased drought.
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影响因子：
5.1
作者：
Buckles, Laura K.;Villanueva, Laura;Damste, Jaap S. Sinninghe
通讯作者：
Damste, Jaap S. Sinninghe
影响因子：
2.6
作者：
Bode, Samuel;De Wispelaere, Lien;Boeckx, Pascal
通讯作者：
Boeckx, Pascal
影响因子：
4
作者：
Blegen, Nick;Brown, Francis H.;Tryon, Christian A.
通讯作者：
Tryon, Christian A.
影响因子：
4
作者：
Berke, Melissa A.;Johnson, Thomas C.;Damste, Jaap S. Sinninghe
通讯作者：
Damste, Jaap S. Sinninghe
影响因子：
5
作者：
Buckles, Laura K.;Weijers, Johan W. H.;Damste, Jaap S. Sinninghe
通讯作者：
Damste, Jaap S. Sinninghe