Collaborative Research: P2C2--Synthesizing Asian Monsoon Hydroclimate & Indo-Pacific Variability on Seasonal to Multi-Decadal Timescales Using Tree-Rings & Coupled Climate

该项目广泛寻求利用东南亚大陆中部老挝和越南的多参数树木年轮记录，重建离散的春、夏、秋和冬季气候变率，以便与观测和模式模拟进行比较，并了解该地区气候和表层海洋变率的动力和驱动因素。从代理记录中获得的MSEA中心变率的长期前景将与模拟相结合，以便对整个东南亚和海洋大陆的大气和上层海洋性质的过去和未来变化有更动态的了解。具体来说，研究小组的目标是利用树木年轮样本中蓝光强度的早期和晚期木材宽度和密度测量，重建过去五到十个世纪的帕尔默干旱严重指数（PDSI）、标准化降水蒸散指数（SPEI）、降雨量和北方冬季最高温度的季节性和多年代际记录。将利用观测/再分析产品和耦合的气候模式模拟来评估过去几个世纪中MSEA中部与印度-太平洋大气和海洋表面特性之间的联系，因为模式分辨率可能无法完全捕捉单个季风季节内的气候和海洋变化。亚洲季风影响着全球大约三分之二的人口。对人为变暖条件下区域气候的多模式评估预测了亚洲季风的变化，预计这些变化将影响区域气候和海洋变率。这些多模式评估还预测了向更类似厄尔尼诺状态的转变，预计这将改变全球降水、温度和海洋环流模式。目前对过去季风强度和降水的变化及其对印度洋表面变率的影响的认识，限制了气候学家在不同时间尺度上准确预测区域气候影响的能力。潜在的更广泛影响（bi）包括更好地了解东南亚和印度太平洋地区降雨和干旱的变化和长期趋势。这些信息对周边国家具有重要意义，这些国家的农业社会主要依赖可靠的季风降雨。该项目还支持一名新的研究者和学生参与伍兹霍尔和UCAR的暑期项目。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project broadly seeks to use multi-parameter tree ring records from Laos and Vietnam in central Mainland Southeast Asia (MSEA) to reconstruct discrete spring, summer, autumn and winter climate variability for comparison to observations and model simulations and to understand the dynamics and drivers of climate and surface ocean variability in the region. The long-term perspective of central MSEA variability from the proxy records will be synthesized with the simulations for a more dynamically-based understanding of past and future changes in atmospheric and upper-ocean properties throughout Southeast Asia and the Maritime Continent.Specifically, the research team aims to use measurements of early and late wood width and density from blue light intensity in tree ring samples to reconstruct seasonal to multi-decadal records of the Palmer Drought Severity Index (PDSI), Standardized Precipitation Evapotranspiration Index (SPEI), rainfall, and boreal winter maximum temperature over the past five to ten centuries. Links between central MSEA and Indo-Pacific atmospheric and surface ocean properties over the past centuries will be evaluated using observational/reanalysis products and coupled climate model simulations because model resolution may not fully capture climate and ocean variability within individual monsoon seasons.The Asian Monsoon impacts roughly two-thirds of the global population. Multi-model assessments of regional climate under anthropogenic warming predict changes to the Asian Monsoon that are expected to impact regional climate and ocean variability. These multi-model assessments also predict a transition to a more El Nino-like state, which is expected to variably alter precipitation, temperature and ocean circulation patterns globally. The present understanding of past changes in monsoon strength and precipitation and the resulting consequences for Indian Ocean surface variability limits climatologist’s ability to accurately forecast regional climate impacts at various timescales.The potential Broader Impacts (B.I.) include better understanding of variability and long-term trends in rainfall and drought from Southeast Asia and the Indo-Pacific region. Such information has important implications for surrounding countries whose largely agrarian societies depend on reliable monsoon rainfall. The project also supports a new investigator and student participation in Woods Hole and UCAR SOARS summer programs.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.