Contrasting early Holocene temperature variations between monsoonal East Asia and westerly dominated Central Asia
Contrasting early Holocene temperature variations between monsoonal East Asia and westerly dominated Central Asia
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对比东亚季风区和西风主导的中亚之间的全新世早期温度变化
DOI：
10.1016/j.quascirev.2017.10.036
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发表时间：
2017
影响因子：
4
通讯作者：
Chen Fahu
中科院分区：
文献类型：
--
作者：
Zhao Jiaju;An Chengbang;Huang Yongsong;Morrill Carrie;Chen Fahu
Numerous studies have demonstrated that there are major differences in the timing of maximum Holocene precipitation between the monsoonal East Asia and westerly dominated Central Asia, but it is unclear if the moisture differences are also associated with corresponding temperature contrasts. Here we present the first alkenone-based paleotemperature reconstructions for the past 21 kyr from Lake Balikun, central Asia. We show, unlike the initiation of Holocene warm conditions at ∼11 kyr BP in the monsoon regions, the arid central Asia remained in a glacial-like cold condition prior to 8 kyr BP and experienced abrupt warming of ∼9 °C after the collapse of the Laurentide ice sheet. Comparison with pollen and other geochemical data indicates the abrupt warming is closely associated with major increase in the moisture supply to the region. Together, our multiproxy data indicate ∼2 thousand years delay of temperature and moisture optimum relative to local summer insolation maximum, suggesting major influence of the Laurentide ice sheet and other high latitude ice sheet forcings on the regional atmospheric circulation. In addition, our data reveal a temperature drop by ∼4 °C around 4 kyr BP lasting multiple centuries, coinciding with severe increases in aridity previously reported based on multiproxy data. In contrast, model simulations display a much less pronounced delay in the initiation of Holocene warm conditions, raising unresolved questions about the relative importance of local radiative forcing and high-latitude ice on temperature in this region.
