Reconstructing Monsoon and Climate Variability from Naimona'nyi Ice Cores, Southwest Himalayas

从喜马拉雅山西南部奈莫纳尼冰芯重建季风和气候变化

• 批准号: 0502476
• 负责人: Lonnie Thompson
• 金额: $ 87.07万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0502476&HistoricalAwards=false
• 关键词: Reconstructing; Monsoon; Climate; Variability; Naimona

This project funds the recovery of two ice cores to bedrock from the Naimona'nyi ice field (30o 27.06N; 81o 19.94' E, 6100 meters above sea level) in the western Tibetan Himalayas and to produce a long, high resolution multi-proxy climate history, including monsoonal variability, for this data-sparse region.The Naimona'nyi ice field is in a distinctly different climate regime from the four previous ice cores recovered from the Tibetan Plateau (TP). This ice field receives nearly equal amounts of summer and winter snowfall. Summer precipitation arrives from the Arabian Sea via the summer monsoon circulation while winter precipitation arrives from more continental sources via winter westerly cyclogenesis. Thus, integration of the Naimona'nyi climate and precipitation histories with contemporaneous records from Dasuopu Glacier, dominated by monsoonal precipitation, will yield more robust and better resolved records of winter snowfall variability and Arabian sea surface temperatures (SSTs) and thus of monsoonal variability that affects highly populated areas of southern Asia. This project has four key scientific goals: (1) to reconstruct high resolution records of temperature, aridity and atmospheric circulation patterns using isotopes of oxygen and deuterium, major ionic chemistry, and insoluble dust measurements; (2) to integrate these records with other paleoclimate histories from the Himalayas to reconstruct the variability of both summer monsoon snowfall and winter precipitation from westerly cyclogenic storms with annual to decadal resolution required to discern abrupt climate changes; (3) to produce a regional fire history; and (4) to determine if older (pre-Holocene) glacial stage ice exists in the dryer western Himalayas.The fifty-eight glaciers on Naimona'nyi once covered an area ten times greater than today, suggesting that the climate in the western Himalayas was once much wetter. The anticipated records from this research, along with other millennial-scale records from both high and low latitudes, will help establish the timing of the onset of low latitude glaciation that is currently hypothesized to be precession driven and asynchronous. Today, evidence is accumulating for an ongoing strong warming throughout the tropics. During the last twenty-four years, the volume of China's 46,298 glaciers has decreased five percent, equivalent to a loss of more than 3,000 km of ice. There has been a notable acceleration in retreat rates since 1990. The ice core records anticipated from Naimona'nyi, coupled with contemporary observations in the region, will further the climate science community's understanding of the climatic factors controlling the recent loss of mass from these ice fields in the western Himalaya.The project presents a strong international collaborative effort between the Institute for Tibetan Plateau Research (ITPR) of the Chinese Academy of Sciences (CAS) and the Ohio State University Byrd Polar Research Center (OSU-BPRC) in scientific research and cultural exchange.

该项目资助将西藏喜马拉雅山脉西部奈莫那尼冰原（北纬 30° 27.06；东经 81° 19.94'，海拔 6100 米）的两个冰芯恢复到基岩，并制作长距离、高分辨率的多代理数据。该数据稀疏地区的气候历史，包括季风变率。Naimona'nyi 冰原的气候状况与之前从青藏高原（TP）发现的四个冰芯。这片冰原的夏季和冬季降雪量几乎相等。夏季降水通过夏季季风环流从阿拉伯海到达，而冬季降水通过冬季西风气旋从更多大陆来源到达。因此，将奈莫纳尼气候和降水历史与以季风降水为主的达索普冰川同期记录相结合，将产生更可靠、更清晰的冬季降雪变化和阿拉伯海表面温度（SST）记录，从而产生季风变化记录，影响南亚人口稠密地区。该项目有四个关键科学目标：（1）利用氧和氘同位素、主要离子化学和不溶性尘埃测量重建温度、干燥度和大气环流模式的高分辨率记录； (2) 将这些记录与喜马拉雅山的其他古气候历史相结合，以重建夏季季风降雪和西风气旋风暴造成的冬季降水的变化，并具有辨别气候突变所需的年度到十年分辨率； (3) 制作区域火灾历史记录； (4) 确定较干燥的喜马拉雅山西部地区是否存在较古老的（全新世前）冰川期冰。奈莫纳尼上的 58 条冰川曾经覆盖的面积是现在的十倍，这表明喜马拉雅山西部的气候曾经湿润得多。这项研究的预期记录，以及来自高纬度和低纬度地区的其他千禧年规模的记录，将有助于确定低纬度冰川作用发生的时间，目前假设该冰川作用是由进动驱动的且异步的。如今，越来越多的证据表明整个热带地区正在持续强烈变暖。过去24年来，中国46,298条冰川的体积减少了5%，相当于流失了3,000多平方公里的冰。自 1990 年以来，退缩率显着加快。奈莫纳尼预计的冰芯记录，加上该地区的当代观测，将进一步促进气候科学界对控制这些冰最近质量损失的气候因素的理解该项目代表了中国科学院（CAS）青藏高原研究所（ITPR）和俄亥俄州立大学伯德极地研究中心（OSU-BPRC）之间强有力的国际合作努力。科学研究和文化交流。