| 晚冰期以来青藏高原降水序列集成重建 |
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| 引用本文： | 侯光良,赖忠平,刘向军,鄂崇毅,魏海成.晚冰期以来青藏高原降水序列集成重建[J].第四纪研究,2019,39(3):615-628. |
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| 作者姓名： | 侯光良 赖忠平 刘向军 鄂崇毅 魏海成 |
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| 作者单位： | 青海师范大学青海省自然地理与环境过程重点实验室,青海西宁,810008;汕头大学海洋科学研究院,广东汕头,515063;西北师范大学地理与环境科学学院,甘肃兰州,730070;中国科学院青海盐湖研究所,中国科学院盐湖资源与化学重点实验室,青海西宁810008 |
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| 基金项目： | 国家自然科学基金;青海省科技厅自然科学研究项目;青海省地理空间信息技术与应用重点实验室基金 |
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| 摘 要： | 选取青藏高原36条(34个地点)由孢粉已重建的降水序列(8条)和化石孢粉谱(28条),分别采用直接提取和现代类比法获得1852个具有年代的定量降水数据,以高原4个分区为单位,建立青藏高原晚冰期以来古降水数据集。构建分区古降水空间模拟-多区面积加权的集成方法,即借助GIS分析,基于现代高原降水空间分布的地理因子模拟,集成重建晚冰期以来高原古降水序列。结果表明:16~12 ka B.P.,高原总体降水量较少,其中16 ka B.P.不到200 mm,约为现代降水量的一半,15~13 ka B.P.后降水显著增长,较前期上升70 mm;13~12 ka B.P.,又跌至220 mm,较现代低100 mm。进入全新世后,降水量迅速增长,降水在全新世早期的9.2~8.7 ka B.P.即达到最大值,高出现代70 mm,9.2~5.0 ka B.P.为全新世湿润期,平均高出现代50 mm;5 ka B.P.之后,降水波动较小,与现代基本持平。集成降水与其他高低分辨率环境记录有很好的可比性,说明集成序列有很好的代表性和一定的准确性。此外,高原降水变化区域差异明显,全新世最大降水呈现出西早东晚,西南季风(ISM)区早于东南季风(EASM)区的特点,高原西部和南部全新世早期9 ka B.P.左右即达极大值,而高原东缘迟至全新世中期的8.0~7.5 ka B.P.;降水增加最为明显的是高原西北部,最盛期降水约高出为现代的1倍,高原东部和南部现季风控制区域,只比现代高出0.2倍。
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| 关 键 词： | 晚冰期以来 青藏高原 降水 集成 |
Synthetically reconstructed precipitation variability in the Qinghai-Tibetean Plateau over the last 16 ka |
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| Hou Guangliang,Lai Zhongping,Liu Xiangjun,E Chongyi,Wei Haicheng.Synthetically reconstructed precipitation variability in the Qinghai-Tibetean Plateau over the last 16 ka[J].Quaternary Sciences,2019,39(3):615-628. |
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| Authors: | Hou Guangliang Lai Zhongping Liu Xiangjun E Chongyi Wei Haicheng |
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| Institution: | (Key Laboratory of Physical Geography and Environmental Processes of Qinghai Province, School of Geographic Science, Qinghai Normal University, Xining 810008, Qinghai;Institute of Marine Science, Shantou University, Shantou 515063, Guangdong;College Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, Gansu;Key Laboratory of Salt Lake Resources and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, Qinghai) |
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| Abstract: | Qinghai-Tibetan Plateau(QTP) is the largest continuous high elevation ecosystem on the earth, which has significant impacts on the global atmosphere circulations. Investigating of the precipitation changes history since last deglaciation on the QTP has significant implication for revealing mechanism of the global climate change. At present, the quantitative reconstructions of paleo-precipitation on the QTP were mostly based on fossil pollen assemblages in different sites. However, these scattered pollen records are still difficult to reflect entirely characteristic of paleo-precipitation variations on the QTP due to the water vapor sources vary greatly. In this study we used pollen to base paleo-precipitation records and pollen assemblages that ther have reliable chronological frameworks during the last deglaciation and Holocene epoch to reconstruct spatial precipitation variations on the QTP. Eight available pollen based on paleo-precipitation data were directly used, and 28 pollen records were used to reconstruct the paleo-precipitation based on the modern analogy method, finally 1852 paleo-precipitation data were obtained. Four sub-region areas were divided to base different geographic environment and moisture sources on the QTP. The equations of modern annual precipitation and geographic locations(longitude and latitude), elevations, slopes and aspects were established, and based on the equations, GIS(geographic information systems) tool was used to reconstruct sub-region paleo-precipitation map by combining the reconstructed the paleo-precipitation data, then the paleo-precipitation of QTP were obtained through area weighted annual precipitation data of four sub-region areas. The results are as follow:(1) The precipitation at ca.16 ka B.P. before present was only half of present precipitation(ca. 200 mm/a) while it was increased about 70 mm during 15~13 ka B.P.;Precipitation was increased rapidly during the Early Holocene(during 11.5~9.2 ka B. P.), and reached the maximum values during 9.2~8.7 ka B. P.(ca. 70 mm more than present);the precipitation increased ca. 50 mm more than that today during 9.2~5.0 ka B. P., which indicated a wet climate condition during Middle Holocene;the precipitation decreased slightly since 5 ka B. P., and similar to the present.(2) Our integrated precipitation was comparable with other climatic proxies during late deglaciation and Holocene on the QTP, which suggested the integrated precipitation sequences was reliable and accurate. In addition, the precipitations varied greatly by space among different sub-regions. The highest precipitation appeared earlier in west QTP than it in east QTP during Holocene. The precipitation was increased 100% than present amount in northwestern QTP, while it was increased 20% in the monsoon controlled eastern and southern QTP. |
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| Keywords: | late glacial precipitation Qinghai-Tibetan Plateau integration |
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