High-Resolution Studies of High Arctic Paleoclimate from Varved Lake Sediments

Varved 湖沉积物对北极高纬度古气候的高分辨率研究

• 批准号: 0402421
• 负责人: Raymond Bradley
• 金额: $ 42.51万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0402421&HistoricalAwards=false
• 关键词: Resolution; Studies; Arctic; Paleoclimate; Varved

This award will be used to help recover annually laminated (varved) sediments from three lakes on northern Ellesmere Island in the Canadian High Arctic to reconstruct Late Holocene climate variations from the last 5,000-6,000 years. The sediments from Ellesmere Island offer the opportunity for high-resolution records of past climate variations in a region where few paleoclimatic records exist. Varve thickness and grain size characteristics of each sedimentary layer may reflect changes in summer temperature conditions in the region. The research will focus on the warmest episodes of the time period. The relationship of summer temperature changes to proxies of past changes in total solar irradiance, episodes of explosive volcanism, and variability in Earth-Sun orbital geometries will be examined to test the hypothesis that solar forcing has influenced climate at high latitudes. This research will be of value to a broad spectrum of researchers across the science community by helping place modern Arctic climate conditions in a long-term perspective by examining the frequency and timing of warm climate episodes in the region over time.

该奖项将用于帮助每年从加拿大高北极北部埃尔斯米尔岛的三个湖泊中恢复每年的层压层（Varved）沉积物，以重建过去5,000至6,000年的全新世气候变化。来自埃尔斯米尔岛（Ellesmere Island）的沉积物为过去几乎没有古气候记录的地区的过去气候变化的高分辨率记录提供了机会。每个沉积层的varve厚度和晶粒尺寸特征可能反映了该地区夏季温度条件的变化。该研究将集中于该时期最温暖的发作。将检查夏季温度变化与过去太阳辐照度，爆炸性火山爆发的发作以及地球阳性几何形状变化的过去变化的关系，以检验以下假设：太阳强迫影响高纬度地区的气候。这项研究将对整个科学界的广泛研究人员具有价值，通过检查该地区温暖气候发作的频率和时机随着时间的流逝，以长期的角度帮助现代北极气候条件。