EAR-PF: Large-scale climate controls on water isotopes in the tropical Pacific: an integrated observational and modeling strategy to improve paleoclimate interpretations

Jessica Conroy博士被授予美国国家科学基金会地球科学博士后奖学金，在乔治亚理工学院开展一项研究和教育计划。康罗伊博士将开展一项多年降水和海水采样计划，以评估赤道太平洋地区日、季节和年际时间尺度上的稳定同位素变化。然后，这些信息将与仪器气候数据相结合，以研究气候对降水和海水中稳定同位素的控制。该项目产生的数据将填补水同位素观测网络的一个关键空白，为与配备同位素的全球气候模型和基于卫星的水同位素检索提供严格的比较。对热带太平洋大尺度气候动力学与水同位素变率之间关系的进一步了解，也将有助于在一系列时间尺度上更准确地解释热带太平洋的关键代用记录。稳定的水同位素的重要性主要在于它们能够提供有关过去气候变化的信息。绝大多数来自珊瑚、洞穴、湖泊沉积物和海洋沉积物的热带太平洋古气候重建都是基于氧和/或氢的稳定同位素值，这些值反映了大尺度水文过程的变化，在碳酸盐档案的情况下，还反映了温度的变化。这些记录的准确解释至关重要，因为该地区的气候变率影响全球气候，最显著的是通过厄尔Niño/南方涛动现象。通常，配备同位素的全球气候模型的输出有助于解释过去气候信息的同位素档案，而代用物的正演模拟则有助于深入了解基于同位素的代用气候记录的主要控制因素。然而，很少有来自热带太平洋的真正同位素测量值来验证气候模型并将其纳入代用物的正演模拟。该项目生成的新数据集将提供这些测量结果，帮助我们了解稳定水同位素变异的控制因素，并准确解释这一重要地区过去的气候变异。与这项研究金有关的计划教育活动包括为当地一所公立高中编写“稳定同位素与气候”课程和学生科学展览项目，以及使太平洋岛民接触到科学数据的收集和解释。该奖学金由大气与地球空间科学部古气候项目资助。

Dr. Jessica Conroy has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at Georgia Institute of Technology. Dr. Conroy will carry out a multi-year precipitation and seawater sampling program to assess stable isotopes variability on diurnal, seasonal, and interannual timescales across the equatorial Pacific Ocean. This information will then be coupled with instrumental climate data to investigate the climate controls on stable isotopes in precipitation and seawater. The data produced from this project will fill a critical gap in observational networks for water isotopes, providing for rigorous comparisons to isotope-equipped global climate models and satellite-based water isotope retrievals. An improved knowledge of the relationship between large-scale climate dynamics and water isotope variability in the tropical Pacific will also allow for more accurate interpretations of key tropical Pacific proxy records across a range of timescales.Much of the importance of stable water isotopes lies in their ability to provide information on past climate change. The vast majority of tropical Pacific paleoclimate reconstructions from corals, speleothems, lake sediments, and marine sediments are based on the stable isotope values of oxygen and/or hydrogen, which reflect changes in large-scale hydrological processes, and, in the case of carbonate archives, temperature. Accurate interpretation of these records is critically important, since climate variability in this region impacts climate across the globe, most notably through the El Niño/Southern Oscillation phenomenon. Typically, output from isotope-equipped global climate models aids in the interpretation of isotope archives of past climate information, and forward modeling of proxies provides insight into the dominant controls on isotope-based proxy climate records. However, there are few real isotope measurements from the tropical Pacific to validate climate models and incorporate into forward modeling of proxies. The new dataset generated from this project will provide these measurements, helping us to understand the controls on stable water isotope variability and accurately interpret past climate variability in this important region. The planned education activities associated with this fellowship include the development of a "Stable Isotopes and Climate" curriculum for a local public high school and student science-fair projects, and the exposure of native Pacific Islanders to scientific data collection and interpretation.This fellowship is supported by the Paleolimate Program in the Division of Atmospheric and Geospace Scieneces.