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

该项目资助了从西藏喜马拉雅山脉西部的纳莫纳尼冰场(30°27.06 N；81°19.94‘E，海拔6100米)恢复两个冰芯到基岩的项目，并为这个数据稀少的地区产生包括季风变化在内的长时间、高分辨率的多代理气候历史。这个冰原的夏季降雪量和冬季降雪量几乎相同。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生成来自更多大陆来源。因此，将纳莫纳尼气候和降水历史与以季风降水为主的达索普冰川的同期记录相结合，将产生关于冬季降雪变率和阿拉伯海表面温度(SSTs)的更可靠和更好分辨率的记录，从而产生影响南亚人口稠密地区的季风变率。该项目有四个关键的科学目标：(1)利用氧和氢的同位素、主要离子化学和不溶尘埃测量来重建温度、干旱和大气环流的高分辨率记录；(2)将这些记录与喜马拉雅地区的其他古气候历史相结合，以重建夏季季风降雪和冬季降水量的变化，所需的年至年代分辨率为年到年代分辨率，以识别突然的气候变化；(3)产生区域火灾历史；以及(4)确定干燥的喜马拉雅西部是否存在更古老的(全新世前)冰川阶段的冰。纳莫纳尼上的58个冰川曾经覆盖的面积是今天的十倍，这表明喜马拉雅西部的气候曾经更潮湿。这项研究的预期记录，以及来自高纬度和低纬地区的其他千年尺度记录，将有助于确定低纬冰川作用开始的时间，目前假设低纬冰川作用是进动驱动的和不同步的。今天，越来越多的证据表明，整个热带地区正在持续强劲变暖。在过去的24年里，中国的46,298个冰川的体积减少了5%，相当于减少了3000多公里的冰。自1990年以来，撤退速度明显加快。Naimona‘nyi预计的冰芯记录，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场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)在科学研究和文化交流方面的强大国际合作努力。

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.