000			02241nab a2200241 4500
003			OSt
005			20231025111257.0
007			cr aa aaaaa
008			231025b |||||||| |||| 00| 0 eng d
100			_aZhang, Tingwei _958815
245			_aHumidity variations spanning the Little Ice Age from an upland lake in southwestern China/
260			_bSage, _c2020.
300			_aVol. 30, issue 2, 2020 ( 289–299 p.).
520			_aA number of archives that span the past ~2000 years suggest that recent variability in hydroclimatic conditions that are influenced by the Asian monsoon in China are unusual in the longer term context. However, the lack of high-resolution precipitation records over this period hampered our ability to characterize and constrain the forcing mechanism(s) of the recent humidity variations. Here, we present the ratio of hematite to goethite (Hm/Gt) derived from the semiquantitative evaluation of the diffuse reflectance spectroscopic analysis as a reliable and effective precipitation proxy to reconstruct the humidity variations during the past 1400 years deduced from Tengchongqinghai Lake sediments, southwestern China. Hm/Gt varied synchronously with variations of Chinese temperature reconstructed from the historical documents and sunspot activity index over the past 1400 years. Critical periodicities of ~450 and ~250 years show that solar activity is the dominant control on precipitation change on centennial scales. However, the relationship determined from Hm/Gt in this study contradicts the stalagmite δ18O interpretations from different regions of China, which exhibit a more complex precipitation pattern that is influenced by the strength of westerly jet in addition to the Asian monsoon. The increased westerly jet during the ‘Little Ice Age’ (LIA) caused a humid climate in southern China and dry conditions in northern and western China.
700			_aYang, Xiaoqiang _958816
700			_aChen, Qiong _958817
700			_aToney, Jaime L _958818
700			_aZhou, Qixian _958819
700			_aGao, Huahong _958820
773	0		_012756 _917200 _dLondon: Sage Publication Ltd, 2019. _tHolocene/ _x09596836
856			_uhttps://doi.org/10.1177/0959683619883026
942			_2ddc _cEJR
999			_c15026 _d15026