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

该项目广泛寻求使用来自东南亚大陆中部（MSEA）的老挝和越南的多参数树木年轮记录来重建离散的春季，夏季，秋季和冬季气候变率，以与观测和模型模拟进行比较，并了解该地区气候和表层海洋变化的动力学和驱动因素。从代理记录的中央MSEA变化的长期观点将与模拟合成，以更动态地了解整个东南亚和海洋大陆的大气和上层海洋特性的过去和未来变化。该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的测量值，重建季节性到多季节性的变化。帕默干旱严重度指数（PDSI），标准化降水蒸散指数（SPEI），降雨量和北方冬季最高温度在过去的五到十个世纪的十年记录。在过去的几个世纪中，中央MSEA和印度洋-太平洋大气和表层海洋属性之间的联系将使用观测/再分析产品和耦合的气候模式模拟进行评估，因为模式分辨率可能无法完全捕捉到个别季风季节内的气候和海洋变化。对人为变暖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将过渡到更类似厄尔尼诺的状态，预计将改变全球降水，温度和海洋环流模式。 目前对季风强度和降水过去变化的理解以及由此产生的印度洋表面变化的后果限制了气候学家准确预测不同时间尺度区域气候影响的能力。包括更好地了解东南亚和印度洋-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，因为这些国家的农业社会主要依赖可靠的季风降雨。 该项目还支持一个新的调查员和学生参与伍兹霍尔和UCAR的腾飞夏季计划。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.