A Terrestrial Perspective of Last Millennium Hydroclimate Variability in the Central Tropical Pacific

上个千年热带太平洋中部水文气候变化的陆地视角

• 批准号: 1602590
• 负责人: Jessica Conroy
• 金额: $ 36.75万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602590&HistoricalAwards=false
• 关键词: Terrestrial; Perspective; Last; Millennium; Hydroclimate

The tropical Pacific plays an enormous role in shaping global climate patterns, yet our understanding of how tropical Pacific climate has varied in the past remains uncertain due to sparse observations across this vast region. This research project will use lake sediments to reveal changes in precipitation and evaporation on the central tropical Pacific island of Kiritimati during the last 1000 years. The outcomes of this project will provide insight into the nature of multidecadal to centennial tropical Pacific climate variability, timescales critical in the context of future climate trends.The proposed research will produce new proxy records of central tropical Pacific climate. Time series of elemental abundance, biological indicators of lake water conductivity, and stable oxygen isotope ratios of ostracod calcium carbonate spanning the last millennium will provide a multi-proxy perspective on past lake water balance and atmospheric moisture balance. In addition, new weather, limnologic and stable oxygen isotope measurements of lake and groundwater will promote a more quantitative understanding of the climate controls on lake water balance within the framework of a proxy system model for lake water and ostracod oxygen isotope ratios. These newly developed records will permit hypothesis testing of whether meridional or zonal changes in atmospheric circulation played a more prominent role in controlling spatial patterns of tropical Pacific hydroclimate variability.

热带太平洋在塑造全球气候模式方面发挥着巨大作用，但由于对这一广阔地区的观测很少，我们对过去热带太平洋气候如何变化的理解仍然不确定。该研究项目将利用湖泊沉积物来揭示过去 1000 年来太平洋中部热带岛屿 Kiritimati 的降水和蒸发变化。 该项目的成果将深入了解数十年至百年热带太平洋气候变化的性质，以及在未来气候趋势背景下至关重要的时间尺度。拟议的研究将产生中部热带太平洋气候的新代理记录。过去一千年的元素丰度时间序列、湖水电导率的生物指标以及介形类碳酸钙的稳定氧同位素比将为过去的湖水平衡和大气湿度平衡提供多代理视角。此外，湖泊和地下水的新天气、湖泊学和稳定氧同位素测量将促进在湖水和介形类氧同位素比率代理系统模型框架内更定量地了解气候对湖泊水平衡的控制。这些新开发的记录将允许对大气环流的经向或纬向变化是否在控制热带太平洋水文气候变化的空间模式中发挥更突出的作用进行假设检验。

项目成果

Last Millennium Meridional Shifts in Hydroclimate in the Central Tropical Pacific

上个千年热带太平洋中部水文气候的经向变化

• DOI: 10.1002/2017pa003233
• 发表时间: 2018-04-01
• 期刊: Paleoceanography and Paleoclimatology
• 影响因子: 3.5
• 作者: M. Higley;J. Conroy;Susan Schmitt
• 通讯作者: Susan Schmitt