Ice Core Reconstruction of North Pacific Climate Variability and Environmental History from the Bona-Churchill Ice Field, Alaska

阿拉斯加博纳-丘吉尔冰原的北太平洋气候变化和环境历史的冰芯重建

• 批准号: 0099311
• 负责人: Lonnie Thompson
• 金额: $ 59.9万
• 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: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0099311&HistoricalAwards=false
• 关键词: Ice; Core; Reconstruction; North; Pacific

AbstractOPP- 00-99311ThompsonThe Principal Investigators will retrieve ice cores from the col between Mt. Bona and Mt. Churchill, located in Wrangell Mountains, southeastern Alaska. The ice core records will fill a significant void in the high resolution climate history of this region and will complement and extend the tree ring-based climate records. These records will be an important contribution to the suite of high resolution ice core histories from other north polar ice fields including, Greenland, Svalbard, the High Canadian Arctic the Windy Dome Ice Cap (Franz Josef Land, Russian Arctic) and Greenland. These polar records are part of a global suite of ice core records including those retrieved from seven lower latitude, high altitude sites in Tibet, South America, and Africa. These cores have contributed critical low-latitude proxy climate histories to the continuing efforts to identify the major drivers of Quaternary climate change and to determine the global synchronicity of glacial-age climate events. Currently, there are no high quality ice core records from Alaska, so these cores should provide critical new insights. The paucity of high resolution climate histories from the northeastern side of the Pacific Basin is a major obstacle to advancing our understanding of the rapid and recent changes in the dynamic state of the Pacific region and its global connections. Of particular interest are: 1) the warming of the last 30 years that appears to be amplified at high elevations in the tropics and subtropics and in northwestern North America and northern Asia; 2) the most recent 'step' change in the dynamics of the Pacific Basin climate regime in 1976-77; and 3) the nature of recently identified multi-decadal ENSO-like mid-latitude climate variability that may have its roots in the tropical Pacific.The field program will include geophysical and surface studies designed to select the best site on the col for recovery of two high resolution, well-preserved ice core records to about 500 meters. The results from laboratory measurements of soluble and insoluble aerosol concentrations will reveal drought and wet periods and relative storm intensities. Oxygen isotope analyses should provide a proxy for the temperature history and past atmospheric circulation patterns in this area. The high annual accumulation and cold mean annual temperatures are good indicators for thick and well preserved annual signals in the physical and chemical records that will allow excellent time control with annual resolution for the last 1000 years. The complete record should extend back at least 5,000 years. The significance of recent climatic and environmental variations must be evaluated from a perspective provided by a globally dispersed, long-term proxy climate records. Linking these records from pole to pole allows assessment of the global nature of these climatic variations and identification of critical linkages between the higher latitudes and the tropics where changes in the global heat source can trigger global-scale changes in the climate system.

AbstractOpp-00-99311ThompsonthompsonThompson The主要调查人员将从位于阿拉斯加东南部Wrangell Mountains的Bona Mt. Bona和Churchill山之间的Col检索冰芯。 ICE核心记录将填补该地区高分辨率气候历史上的重要空隙，并将补充和扩展基于树环的气候记录。这些记录将是对来自其他北极冰场的高分辨率冰核历史套件的重要贡献。 这些极地记录是全球冰核心记录的一部分，包括从七个较低纬度，西藏，南美和非洲的高海拔地区检索到的记录。 这些核心为持续的努力贡献了关键的低纬度替代气候历史，以确定第四纪气候变化的主要驱动力，并确定冰川年龄气候事件的全球同步性。目前，阿拉斯加没有高质量的冰核记录，因此这些核心应提供关键的新见解。 从太平洋盆地东北方面的高分辨率气候历史的匮乏是促进我们对太平洋地区动态状态及其全球联系的快速和最新变化的理解的主要障碍。 特别感兴趣的是：1）在热带和亚热带以及北美西北部和北亚的高海拔地区，过去30年的变暖似乎被放大； 2）1976 - 77年太平洋盆地气候制度动态的最新“步骤”变化； 3）最近确定的多年ENSO样中纬度气候变异性的性质可能具有其根源在热带太平洋地区。该田间计划将包括地球物理和表面研究，旨在选择旨在选择COL上的最佳地点，以恢复两种高分辨率，可保存良好的冰核心记录约为500米。 实验室测量可溶性和不溶性气溶胶浓度的结果将揭示干旱和潮湿的时期以及相对的风暴强度。 氧同位素分析应为该区域的温度病史和过去的大气循环模式提供代理。 年度高积累和冷平均年度温度是物理和化学记录中厚实保存完好的年度信号的良好指标，在过去的1000年中，可以通过年度分辨率进行良好的时间控制。完整的记录应延长至少5，000年。最近的气候变化和环境变化的重要性必须从全球分散的长期代理气候记录提供的角度评估。将这些记录从极点连接到极点，可以评估这些气候变化的全球性质，并识别较高纬度和热带地区之间的关键联系，而全球热源的变化可以触发气候系统的全球规模变化。