High-Resolution Quantitative Reconstructions of Holocene Climatic Changes and Their Impacts on Environment and People in the Central Canadian Arctic

该合同将用于获得全新世热最大值（HTM）期间夏季温度变化的定量估计，并评估其对北极的影响。具体来说，研究人员将记录距今8200年前（B.P.）事件（全新世冰芯记录中明显的急剧气候逆转）的发生和规模，检查太阳变化对北极气候的影响，并调查气候变化对当地人的影响。研究人员将从湖泊沉积物岩心中提取摇虫、硅藻和花粉化石样本，以产生维多利亚岛和邻近加拿大大陆夏季温度的传递函数。热媒的记录将被审查，以评估长期变暖对北极的影响。这种变暖表明热HTM不是一个单峰事件，而是发生在距今1500年至6500年之间的一系列温度峰值，这表明热HTM与太阳变率呈正相关。考古记录显示，古爱斯基摩人于公元前4500年在维多利亚岛定居，但在公元前3800年人口迅速减少。这一时期的高分辨率记录将有助于确定人口减少是由于人类的影响（即，过度捕捞麝牛）还是气候变化导致人口锐减。这项研究将考察北极气候变率，这是科学界和科学政策界关注的一个关键问题。该奖项将促成广泛的国内和国际科学伙伴关系，并支持几名美国研究生和本科生作为研究伙伴。

This award will be used to obtain quantitative estimates of summer temperature variations during the Holocene Thermal Maximum (HTM) and assess its impact in the Arctic. Specifically, the researchers will document the occurrence and magnitude of the 8,200 year before present (B.P.) event (a sharp climatic reversal distinct in Holocene ice core records), examine the influence of solar variability on Arctic climate, and investigate the impact of climate change on native people.The researchers will sample fossil chironomids, diatoms, and pollen from lake sediment cores to produce a transfer function of summer temperatures for Victoria Island and adjacent continental Canada. Records of the HTM will be examined to assess the impact of prolonged warming on the Arctic. This warming indicates that the HTM was not a unimodal event, but a series of temperature peaks occurring between 1,500 and 6,500 years B.P. This suggests a positive correlation with solar variability.The archaeological record shows that Paleoeskimos were established on Victoria Island by 4,500 years B.P. but suffered a rapid population decline by 3,800 years B.P. High-resolution records during this period would help determine if the decline was from human influence (i.e., over-harvesting of musk-ox) or if a change in climate led to the human population crash.This research will examine Arctic climate variability, a key issue of scientific concern to the broader scientific and science policy communities. The award will enable extensive national and international partnerships in science and support several American graduate and undergraduate students as partners in the research.