P2C2: Seasonal Dynamics of the Indo-Asian Monsoon during Deglaciations

P2C2：冰消期印度-亚洲季风的季节动态

• 批准号: 1603065
• 负责人: Ian Orland
• 金额: $ 22.57万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-15 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1603065&HistoricalAwards=false
• 关键词: P2C2; Seasonal; Dynamics; Indo; Asian

This projects aims to better constrain the seasonal behavior of Indo-Asian monsoon rainfall and related atmospheric dynamics (e.g. the jet stream) during climate transitions at the end of both the last and penultimate ice ages. The researchers will use recently developed methods for ion microprobe analysis to measure oxygen isotope ratios (delta18-Oxygen) recorded in the calcite mineral structure of speleothems at seasonal resolution. The speleothem delta18-Oxygen values record changes in past rainfall amount, source, and seasonality that are preserved as the speleothem grows, generating a record of past rainfall changes that can span tens to hundreds of thousands of years. Studies of past changes in precipitation are important because they potentially provide valuable insight on the fundamental controls and potential response of rainfall during climate transitions.The research team will analyze speleothems from Yemen and Israel to complement seasonal-resolution analyses from northeastern China. These samples represent a component of atmospheric circulation over Asia, each with an important seasonal component: the Westerlies (Israel), Indian Monsoon (Yemen), and East Asian Monsoon (China). Additionally, the team will to use global climate model simulations (i.e., Community Climate System Model version 3, TraCE-21K Community Atmosphere Model version 3) of rainfall delta18-Oxygen to assess the level of coherence between modeled and observed seasonal rainfall patterns across Asia during key climatic periods that followed the last two ice ages. The team will model a suite of seven diagnostic time-slices from these two periods when large changes in monsoon rainfall, including during a warming event ~11,500 years ago when an abrupt decadal-scale change may have occurred.The Broader Impacts involve supporting two early career scientists in research that could help improve the understanding of the timing and monsoonal rainfall. The Impacts also include participating in outreach programs with the UW-Madison Geology Museum.

该项目旨在更好地限制印度 - 亚洲季风降雨和相关大气动态的季节性行为（例如，喷气流）在最后一个和倒数第二个冰河时代结束时气候过渡期间的季节性行为。研究人员将使用最近开发的离子微探针分析的方法来测量在季节性分辨率下speleothems的方解石矿物结构中记录的氧同位素比（Delta18-氧）。 随着speleothem的增长，保留的过去降雨量，来源和季节性的speleothem delta18-氧气值记录了记录的变化，从而产生了过去的降雨变化的记录，这些变化可能跨越数十万年。 对过去降水变化的研究很重要，因为它们有可能对气候过渡期间的基本控制和降雨的潜在反应提供宝贵的见解。研究小组将分析从也门和以色列的speleothems，以补充来自中国东北部的季节性分辨率分析。这些样品代表了亚洲大气环流的组成部分，每个循环都有一个重要的季节性组成部分：西风（以色列），印度季风（也门）和东亚季风（中国）。此外，该团队将使用全球气候模型模拟（即社区气候系统模型版本3，Trace-21k社区大气模型版本3）的降雨量Delta18-氧气来评估在过去两次ICE时期的关键气候期间，亚洲各地的建模和观察到的季节性降雨模式之间的相干性水平。 该团队将对这两个时期的七个诊断时间分段进行建模，当时季风降雨发生较大变化，包括在变暖事件中发生〜11,500年前，可能发生了突然的衰老阶段变化，更广泛的影响涉及支持两名早期职业科学家的研究，这可以帮助提高对定时和季度降雨的理解。影响还包括与UW-Madison地质博物馆一起参加外展计划。

项目成果

Comparison of δ 18 O analyses on individual planktic foraminifer ( Orbulina universa ) shells by SIMS and gas-source mass spectrometry

通过 SIMS 和气源质谱法对单个浮游有孔虫 (Orbulina universa) 壳进行 δ 18 O 分析的比较

• DOI: 10.1016/j.chemgeo.2018.02.028
• 发表时间: 2018
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Wycech, Jody B.;Kelly, Daniel Clay;Kozdon, Reinhard;Orland, Ian J.;Spero, Howard J.;Valley, John W.
• 通讯作者: Valley, John W.