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.

该项目资助从Naimona'nyi冰原恢复两个冰芯到基岩（30 ° 27.06N; 81 ° 19.94' E，海拔6100米），并产生一个长的，高分辨率的多代理气候历史，包括季风变率，Naimona'nyi冰场与之前从青藏高原（TP）恢复的四个冰芯处于明显不同的气候状态。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来自阿拉伯海，而冬季降水则通过冬季西风气旋生成来自更多的大陆来源。因此，整合Naimona'nyi的气候和降水历史与同期记录从Dasuopu冰川，占主导地位的季风降水，将产生更强大的和更好的解决记录的冬季降雪变化和阿拉伯海表面温度（SST），从而季风变化，影响人口稠密地区的南亚。该项目有四个关键的科学目标：（1）利用氧和氘的同位素、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;（二）将这些记录与喜马拉雅山的其他古气候历史相结合，重建夏季风降雪和冬季降水的变化，10年分辨率需要辨别气候突变;（3）产生区域火灾历史;（4）确定是否更古老的（前全新世）冰川期冰存在于干燥的西喜马拉雅山。Naimona'nyi的58个冰川曾经覆盖的面积是今天的十倍，这表明西喜马拉雅山的气候曾经更加潮湿。这项研究的预期记录，沿着来自高纬度和低纬度的其他千年尺度记录，将有助于确定低纬度冰川作用开始的时间，目前假设低纬度冰川作用是岁差驱动的和异步的。今天，越来越多的证据表明整个热带地区正在发生强烈的变暖。在过去的24年里，中国46,298条冰川的体积减少了5%，相当于减少了3,000多公里的冰。自1990年以来，撤退速度明显加快。从Naimona'nyi预期的冰芯记录，加上该地区的当代观测，将进一步加深气候科学界对控制喜马拉雅西部冰原物质损失的气候因素的理解。该项目是中国科学院青藏高原研究所（ITPR）与和俄亥俄州州立大学伯德极地研究中心（OSU-BPRC）在科学研究和文化交流。