P2C2: Western Pacific Warm Pool Hydroclimate during the Last Glacial Maximum and the Deglaciation

西太平洋暖池（WPWP）在全球水文循环中起着重要的作用，其变化在世界范围内具有重要的社会经济影响。了解过去的气候条件可以改善对这一关键地区及其他地区未来气候变化的预测。这项研究将通过研究两个关键时期的洞穴形成（石笋）来扩展WPWP古气候数据的空间和时间分辨率：末次盛冰期（LGM; 19，000 - 21，000年前），当时的平均气候比今天冷得多，以及冰川消退（11，000 - 19，000年前），在此期间全球气候经历了突然的变化。来自一个网站和模型输出网络的洞穴数据之间的比较将加强气候解释，并将提高重建和气候模型的保真度。这项研究将产生时间序列的石笋d18 O，在热带地区的降雨量，从菲律宾（东部，中部和西部网站），所罗门群岛，瓦努阿图的既定代理。这些站点涵盖了现代时期所见的各种降水变率，并将在目前几乎没有数据的站点提供有关过去气候变率的信息。本研究将通过重建从末次冰期到全新世的降雨量，对WPWP水文对气候变化的全方位响应进行采样。冷末次盛冰期和暖全新世的端部成员提供了一个衡量WPWP降雨对全球平均温度有多敏感的指标。冰川消退期间的时间演变揭示了与突发气候事件相关的WPWP降雨变化的幅度和空间格局，以及热带地区在这些事件中的作用。这些代用数据将与来自CMIP 5和PMIP 2/PMIP 3档案和其他来源的各种气候模式模拟进行比较，重点是气候变化的空间格局和季节性，以及不同模式的共性和多样性。为了研究过去气候突变的遥相关机制，还将利用一个大气模式进行更多的实验。代理模式的比较将有助于验证用于未来气候预测的气候模式，详细的模式分析和额外的实验将阐明过去气候突变的机制。研究小组将与瓦努阿图和菲律宾等发展中国家的当地科学家密切合作，交流有关气候问题和水资源供应的知识，这些问题对小岛屿国家具有社会和安全影响。该项目将提供一个研究经验的本科生通过GEOFORCE计划，这是一个选择性的推广计划的杰克逊地球科学学院，培训高中学生，主要是从人口在地球科学中代表性不足，并让他们参与实地考察招募。

The West Pacific Warm Pool (WPWP) plays an important role in the global hydrological cycle, and its variability has significant socioeconomic consequences around the world. Understanding past climate conditions can improve predictions of future climate changes in this key region and beyond. This study will extend both the spatial and temporal resolution of paleoclimate data for the WPWP by studying cave formations (stalagmites) for two key periods: the Last Glacial Maximum (LGM; 19,000-21,000 years ago), when the mean climate was much colder than today, and the deglaciation (11,000-19,000 years ago), during which the global climate went through abrupt changes. Comparison between the cave data from a network of sites and model outputs will strengthen the climate interpretations made, and will improve the fidelity of both the reconstructions and the climate models. This study will generate time series of stalagmite d18O, an established proxy for rainfall amount in the tropics, from the Philippines (eastern, central, and western sites), the Solomon Islands, and Vanuatu. These sites cover a wide range of precipitation variability, as seen during the modern era, and will provide information about past climate variability at sites that currently have little to no data. This study will sample the full range of the WPWP hydrologic response to climate change by reconstructing rainfall from the LGM to the Holocene. The end members of the cold LGM and the warm Holocene provide a measure of how sensitive WPWP rainfall is to global mean temperature. The temporal evolution during the deglaciation reveals the magnitude and spatial pattern of WPWP rainfall changes associated with abrupt climate events, and how much of a role the tropics participate in these events. The proxy data will be compared with various climate model simulations from the CMIP5 and PMIP2/PMIP3 archives and other sources, focusing on the spatial pattern and seasonality of climate changes, as well as the commonalities and diversity of different models. To investigate the teleconnection mechanisms of past abrupt climate changes, additional experiments will also be conducted with an atmospheric model. The proxy-model comparison will help validate climate models, which are being used for future climate projections, and the detailed model analysis and additional experiments will elucidate the mechanism of past abrupt climate changes. The research team will work closely with local scientists in the developing countries of Vanuatu and the Philippines, exchanging knowledge about climate issues and water availability, issues that have societal and security implications for small island nations. The project will provide a research experience an undergraduate student recruited through the GEOFORCE program, which is a selective outreach program of the Jackson School of Geosciences that trains high school students, mainly from demographic underrepresented in the geosciences, and involves them in fieldwork.