Temperature and humidity patterns since the Medieval Warm Period:Evidence from Yejiping peat from western Guizhou Plateau,SW China
The past millennium represents a critical period for global change research,yet there remains a lack of consensus on the temperature-humidity patterns and the driving mechanisms due to differences in research methodologies and proxy records.The Medieval Warm Period(MWP)and the Little Ice Age(LIA)are widely recognized as significant climate episodes during this time,but the temperature-humidity patterns associated with these periods vary regionally.In particular,the spatial differences and influencing factors in southwestern China remain understudied.The western Guizhou Plateau(WGP),situated in the northeast of the Yunnan-Guizhou Plateau within the hinterland of the Wumeng Mountains,is particularly sensitive to climate and envir-onmental changes.The Yejiping peat,located in the subalpine karst region of the WGP and influenced by the southern branch of the westerlies,offers a highly detailed and continuous record of climate variability during the MWP and LIA.In this study,we measured the water content,loss on ignition(LOI),and carbonate content of sediments from the Yejiping peat core(YJP01).High-resolution,continuous X-ray fluorescence core scan-ning was utilized to determine the geochemical element content and chromaticity of the samples.By analyzing the activity,content,and ratios of geochemical elements,and applying multivariate statistical techniques such as cluster and correlation analyses,we identified the sources of the primary elements in the Yejiping peat sedi-ments and their environmental implications.A robust chronological framework was established using high-density AMS14C dating,enabling us to reconstruct a detailed paleoclimate evolution from the MWP to the LIA on the WGP.This study also discusses the spatial patterns of climate variability during the MWP and LIA.Our results revealed the following key findings:1)Multiple proxies from the Yejiping peat indicate that the climate was warm and humid during the MWP(1 200-1 450)and cold and dry during the LIA(1 450-1880),which aligns with other regional paleoclimate records.2)The"warm-wet and cold-dry"as well as"warm-dry and cold-wet"climate characteristics coexisted in southwestern China during the MWP and LIA,demonstrating a clear spatial differentiation between the eastern and western regions of the area.3)The movement of the westerlies,particularly their shifts northward or southward,significantly influenced the hydrothermal patterns in south-western China throughout the past millennium.This study,therefore,provides a comprehensive understanding of regional climate variability and its controlling mechanisms during key climatic periods,contributing valu-able insights into the broader picture of global climate evolution.
westerliesYejiping peatX-ray fluorescence core scanningLittle Ice AgeKarst region
万方数据
维普
