Collaborative Research into Indo-Asian Monsoon Variability: Data and Model Assessment of Northern- and Southern-Hemisphere Mechanisms

根据这个奖项π将亚洲季风系统的生成和分析代理记录间隔从5到200万年前现在和运行一组核心的八GCM实验将测试三个假设关于关键气候过程导致集约化和印度和亚洲季风的演化:1)强劲的时机北半球summer-monsoons更敏感的出口从南半球潜热比直接的明智的2)北半球大尺度冰量的产生和发展增强了冬季风，减弱了夏季风，是观测到的与轨道强迫（即与日照强迫相关的最强夏季风漂移时间）有关的非平稳相位响应的根本原因。(3)冬季和夏季风环流的强度与北半球冰川演化是动态耦合的。利用地质记录来检验这些假设，将通过分析和比较从3.2 Ma到现在的快速演变的高冰量间隔和温暖的、相对稳定的最小冰间隔5到3.2 Ma期间的季风响应来完成。结合数据/模式策略分析地球历史上具有非常不同大尺度边界条件的两个时间间隔的季风变率，将使在轨道时间尺度上区分造成季节季风变率的内部（气候反馈）和外部（日照）机制成为可能。

Under this award the PIs will generate and analyze proxy records of the Asian monsoon system over the interval from 5 to 2 million years before present and to run a core set of eight GCM experiments which will test three hypotheses regarding key climate processes that lead to intensification and evolution of the Indian and Asian monsoons:1) The timing of strong Northern Hemisphere summer-monsoons is more sensitive to the export of latent heat from the Southern Hemisphere than to direct sensible heating over Asia.2) The initiation and development of large-scale ice volume in the Northern Hemisphere strengthens the winter monsoon, weakens the summer monsoon and is the root cause of the observed non-stationary phase response relative to orbital forcing (i.e. the timing of the strongest summer-monsoon drifts relative to insolation forcing).3) The intensity of winter- and summer-monsoon circulation is dynamically coupled and linked to glacial evolution in the Northern Hemisphere. Testing these hypotheses using the geological record will be accomplished by analyzing and comparing the monsoon response during the rapidly evolving, high ice-volume interval from 3.2 Ma to present and the warm, relatively stable, minimal ice interval 5 to 3.2 Ma. The combined data/model strategy of analyzing monsoon variability during two intervals of Earth history with very different large-scale boundary conditions will enable differentiation of internal (climate feedback) and external (insolation) mechanisms responsible for seasonal monsoon variability at orbital time scales.