Glacial fluctuations in tropical Africa during the last glacial termination and implications for tropical climate following the Last Glacial Maximum
Glacial fluctuations in tropical Africa during the last glacial termination and implications for tropical climate following the Last Glacial Maximum
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DOI：
10.1016/j.quascirev.2020.106455
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发表时间：
2020-09-01
影响因子：
4
通讯作者：
Nakileza, B.
中科院分区：
文献类型：
--
作者：
Jackson, M. S.;Kelly, M. A.;Nakileza, B.
热带地区是全球气候系统的一个动态组成部分，对现代气候变率有着深远的影响。然而，热带地区在过去气候变化中的作用，例如在最后一次冰川终止期间，是不确定的。这种不确定性的部分原因是热带地区的陆地温度记录相对较少，这阻碍了对影响冰消期变暖和突发气候事件的机制的理解。热带冰川对气候变化很敏感，过去热带冰川波动的测绘和测年提供了低纬度陆地气候变化的宝贵记录。我们报告的年表过去的冰川范围在乌干达的鲁文佐里山脉（0.3度N，29.9度E）的基础上51铍-10（Be-10）的表面暴露年龄从三个独立的冰川集水区。结果表明，鲁文佐里冰川退缩相当海因里希体育场1。净冰川衰退的速度在15到11万年之间放缓，尽管在此期间冰川继续退缩。在全新世早期，鲁文佐里冰川退缩得更快。鲁文佐里冰川年表与东非和南美洲热带地区其他地方重建的冰川年表大致相似。我们认为，这种相似性可能反映了连贯的，热带地区的温度波动在最后一次冰消期。鲁文佐里冰川年代学提供了关于冰川消融期变暖和气候突变事件的全球足迹的重要信息，从而提供了在末次冰期终止期间影响热带气候的潜在机制。(C)2020爱思唯尔有限公司保留所有权利。
The tropics are a dynamic component of the global climate system and exert a profound influence on modern climate variability. Yet the role of the tropics in past climate changes, for example during the last glacial termination, is uncertain. This uncertainty is due in part to the relative paucity of terrestrial temperature records from the tropics, which hinders efforts to understand the mechanisms that influenced deglacial warming and abrupt climate events. Tropical glaciers are sensitive to changes in climate, and mapping and dating past tropical glacial fluctuations provides a valuable record of terrestrial climate changes in the low latitudes. We report a chronology of past glacial extents in the Rwenzori Mountains of Uganda (0.3 degrees N, 29.9 degrees E) based on 51 beryllium-10 (Be-10) surface-exposure ages from three separate glacial catchments. Results indicate that Rwenzori glaciers retreated considerably during Heinrich Stadial 1. The rate of net glacial recession slowed between similar to 15 and 11 ka, although glaciers continued to retreat during this period. Rwenzori glaciers then retreated more rapidly during the early Holocene. The Rwenzori glacial chronology is broadly similar to glacial chronologies reconstructed elsewhere in East Africa and in tropical South America. We suggest that this similarity may reflect coherent, tropics-wide temperature fluctuations during the last deglaciation. The Rwenzori glacial chronology provides crucial information on the global footprint of deglacial warming and abrupt climate events and, thus, the potential mechanisms that influenced tropical climate during the last glacial termination. (C) 2020 Elsevier Ltd. All rights reserved.