Collaborative Research: P2C2--Unravelling the Signals in Tropical Pacific Lake Archives: Towards Improved Holocene Hydroclimate Reconstructions

这个项目的目标是使用一个新的跨学科工具箱来解决站点间的不确定性，方法是将现有的湖泊沉积岩心记录与现有的全球气候模式相结合，以模拟大气水分输送，建立替代系统模型，并最终提高对热带降水可变性和变化的理解。全球范围内，年际降水可变性的最大单一原因与厄尔尼诺-南方涛动(ENSO)现象有关。关于ENSO对降水的预测反应的大小和方向，仍然存在很大的不确定性。从亚马逊、安第斯和加拉帕戈斯群岛开发了许多湖泊沉积物古气候重建，目的是了解ENSO和热带水气候(即降水量、强度和季节性)对过去气候变化的响应。然而，这些记录之间的不一致使应对气候风险和水文气候极端情况的能力复杂化。该项目的具体目标是：(I)改进对热带湖泊沉积物档案的解释，并利用高分辨率湿度跟踪模拟与综合气候模型进行代理模型比较；(Ii)限制从早期全新世到现在的热带古气候记录的敏感性；以及(Iii)利用气候模型模拟合成湖泊气候重建的气候，以了解热带水气候在空间和时间尺度上的可变性。潜在的更广泛的影响包括更好地理解全新世热带水气候可变性的规模、时间和驱动因素。该项目还将为两名职业生涯早期的研究人员、一名博士后研究员、两名研究生和本科生提供支持。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project aims to use a new interdisciplinary toolbox to resolve inter-site uncertainties by synthesizing existing lake sediment cores records with existing global climate models to simulate atmospheric moisture transport, build proxy-system models, and ultimately improve the understanding of tropical precipitation variability and change.The largest single cause, globally, in interannual precipitation variability is associated with the El Nino-Southern Oscillation (ENSO) phenomenon. Large uncertainties remain regarding the magnitude and direction of the projected precipitation response with ENSO. Numerous lake sediment paleoclimate reconstructions have been developed from the Amazon, Andes, and Galapagos Archipelago with the goal of understanding the response of ENSO and tropical hydroclimate (i.e., precipitation amount, intensity, and seasonality) to past climate changes. Disagreement between these records, however, complicates the ability to prepare for climate risks and hydroclimate extremes.This project specifically aims to: (i) improve the interpretation of tropical lake sediment archives and facilitate proxy-model comparisons using high-resolution moisture tracking simulations with a comprehensive climate model; (ii) constrain the sensitivity of tropical paleo-climate records from the early-Holocene to present; and (iii) synthesize climate reconstructions from lakes with climate model simulations to understand tropical hydroclimate variability across spatial and temporal scales.The potential Broader Impacts include improved understanding of the magnitude, timing, and drivers of tropical hydroclimate variability over the Holocene. The project will also provide support for two early-career researchers, a postdoctoral fellow, two graduate students, and undergraduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.