Collaborative Research: Holocene Hydrologic Variability across the Western Pacific Warm Pool

本项目通过从关岛、所罗门群岛、瓦努阿图和菲律宾的洞穴中获得的水文记录，探讨了西太平洋暖池（WPWP）全新世（过去1万年）降水的时空变化。这项研究的总体目标是确定热带太平洋在推动全新世全球水文循环的变化中是否发挥了主动或被动的作用。正在进行的研究问题包括：全新世以来，日照强迫是否直接导致了与季风和热带辐合带（ITCZ）相关的经向变化？外部日照强迫是否通过纬向变化（ENSO）诱发了热带太平洋的内部变化，从而导致全新世西太平洋的降水变化？该项目的具体目标包括：1)以十年尺度分辨率测量关岛、瓦努阿图、所罗门群岛和菲律宾过去1万年的岩洞样品的铀系列年龄和氧同位素组成；2)通过对比不同气候动力站点的古气候记录，确定近1万年来西洋滩的时空水文变异，以分离ENSO动力和季风动力对西洋滩的影响；3)回到WPWP的遗址收集更多的洞穴特征、洞穴滴水、基岩和土壤，以确保我们准确地解释洞穴记录。更广泛的影响包括将古气候重建与水文研究联系起来。这为区域和地方水资源管理提供了潜在的好处。该项目还将支助德克萨斯大学奥斯汀分校的一名博士后研究员和关岛大学的一名硕士学生。

This project explores any spatial and temporal changes in precipitation over the Holocene (last 10,000 years) across the Western Pacific Warm Pool (WPWP) from hydrologic records generated from speleothems from Guam, Solomon Islands, Vanuatu, and the Philippines. The overall goal of the research is to determine if the tropical Pacific played an active or passive role in driving the changes in the global hydrological cycle over the Holocene.The research questions being pursued include: Did insolation forcing directly cause meridional changes associated with the monsoon and InterTropical Convergence Zone (ITCZ) in the WPWP over the Holocene? Did external insolation forcing induce internal changes in the tropical Pacific via zonal changes, or ENSO, to cause precipitation changes in the WPWP over the Holocene?Specific objectives of the project include: 1) measuring Uranium-series ages and oxygen isotopic composition of speleothem samples from Guam, Vanuatu, the Solomon Islands, and the Philippines for the last 10,000 years at decadal-scale resolution; 2) determining the spatial and temporal hydrologic variability across the WPWP for the last 10,000 years by comparing paleoclimate records from sites that experience different climate dynamics to separate the influence of ENSO dynamics and monsoon dynamics on WPWP; and 3) returning to the sites in the WPWP to collect additional speleothems, cave dripwaters, bedrock and soils to ensure that we accurately interpret the speleothem recordsThe broader impacts involve linking paleoclimate reconstructions with hydrologic studies. This provides potential benefits for regional and local water resources management. The project would also support a post-doctoral fellow at the University of Texas at Austin and a M.S. student at the University of Guam.