Collaborative Research: Water Balance of western North America:  Dynamics of the Miocene summer monsoon

0450221 Diffenbaugh本项目通过应用一种创新的方法，将降水模式的变化与东太平洋和墨西哥湾的海表面温度(SST)变化联系起来，重点分析了中新世时期美国西部的水平衡。与现代美国西部普遍的干旱气候相比，中新世中期的气候条件要潮湿得多，尽管大气中的二氧化碳水平相似。该项目将确定海温变化如何影响水从海洋到陆地的净转移，方法是利用现有的海洋钻探计划沉积物岩心重建中、晚中新世的海温时间序列，使用气候变化的陆地代用品对时间序列进行地面探测，通过应用区域和全球气候模式来模拟SST变化对美国西部气候条件的影响。该项目将产生第一个受到良好约束的中新世SST记录，并将提供预测中新世气候条件的模拟结果，也可以用于确定变暖事件对美国西部未来干旱的潜在影响。该项目的更广泛影响包括水循环和区域气候变化之间的联系，支持相对较新的博士作为主要研究人员，以及研究生和本科生的培训。

0450221DiffenbaughThis project focuses on the analysis of the water balance in the Western U.S. during Miocene time through the application of an innovative approach that links changes in precipitation patterns to sea surface temperature (SST) variations in the eastern Pacific and Gulf of Mexico. In contrast to the prevailing arid climate of the modern Western U.S., conditions during middle Miocene time were far wetter despite similar atmospheric carbon dioxide levels. This project will determine how SST variations affect the net transfer of water from ocean to land by using existing Ocean Drilling Program sediment cores to reconstruct a SST time series for the middle and late Miocene, by groundtruthing the time series using terrestrial proxies for climate change, and by applying both regional and global climate models to simulate the impact of SST variations on climate conditions in the Western U.S. The project will produce the first well-constrained SST record for Miocene time and will provide modeling results that hindcast Miocene climate conditions and that may also be applied in a predictive sense to determine the potential impact of warming episodes on the future aridity of the Western U.S. Broader impacts of the project include linkages between the water cycle and regional climate change, support for relatively recent PhDs as principal investigators, and training of graduate and undergraduate students.