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在最后一个和倒数第二个冰河时代结束时气候转变期间印度-亚洲季风降雨和相关大气动力学（例如急流）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方法，以季节分辨率测量洞穴沉积物方解石矿物结构中记录的氧同位素比（δ 18-氧）。 洞穴沉积物δ 18-氧值记录了过去降雨量、来源和季节性的变化，这些变化随着洞穴沉积物的生长而保存下来，从而记录了过去降雨量的变化，这些变化可以跨越数万年到数十万年。 对过去降水变化的研究非常重要，因为它们可能为气候转变期间降雨的基本控制和潜在响应提供有价值的见解。研究小组将分析也门和以色列的洞穴沉积物，以补充中国东北部的季节分辨率分析。这些样本代表了亚洲上空大气环流的一个组成部分，每个都有一个重要的季节性组成部分：西风带（以色列），印度季风（也门）和东亚季风（中国）。此外，该小组将使用全球气候模型模拟（即，社区气候系统模式第3版、TraCE-21 K社区大气模式第3版）的降雨量增量18-氧气，以评估在最近两个冰河期之后的关键气候时期，模拟和观测到的亚洲各地季节性降雨模式之间的一致性水平。 该团队将从这两个时期的季风降雨发生巨大变化的七个诊断时间片中建模，包括大约11，500年前的变暖事件期间，当时可能发生了突然的十年尺度变化。更广泛的影响涉及支持两名早期职业科学家的研究，这可能有助于提高对时间和季风降雨的理解。影响还包括参与与威斯康星大学麦迪逊分校地质博物馆的外联方案。

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.