Evolution of Indian Summer Monsoon to its current strength (eISM)

印度夏季风(ISM)是固体地球和大气过程耦合的结果。ISM是由于中亚上空气团的异常加热导致形成的低压系统，该系统从周围的海洋吸收潮湿的空气，导致印度支那和南亚地区的强烈降水，影响数十亿人。造成这一低压系统强度的过程与印度与亚洲在大约50 Ma(百万年前)新生代第一次碰撞以来的区域构造有关。季风气候的强度，特别是降雨，如何影响大陆侵蚀，从而影响喜马拉雅和西藏的折返和隆升，这在很大程度上是未知的，主要是因为对新生代季风演化的约束很差。之前就过去ISM强度达成共识的努力，由于缺乏连续的沉积序列和强大的替代物而受阻。该项目，即eISM，将通过以下方式解决这些缺点：(A)通过国际海洋发现方案(IODP)考察队353次探险，利用在孟加拉湾和安达曼海的三个地点新钻探的沉积物序列，以及(B)应用盐度(海水的氧同位素和浮游有孔虫的Ba/Ca比)和侵蚀强度(根据大宗元素比)重建ISM降水演变的测试指标。EISM产生的季风记录将有助于与日益受到良好约束的陆上构造历史相关联，以了解和量化气候调制过程在控制地球构造演化方面的影响。

The Indian Summer Monsoon (ISM) is a result of coupled solid Earth and atmospheric processes. The ISM is due to anomalous heating of the air mass over central Asia resulting in the formation of a low-pressure system that draws moist air from the surrounding oceans resulting in intense precipitation across Indochina and south Asia, impacting billions of people. The processes responsible for intensity of this low-pressure system over the continent is related to the regional tectonics since the initial collision of India with Asia around 50 Ma (million year ago) during the Cenozoic. How intensity of monsoon climate, especially rainfall, affects continental erosion and consequently exhumation and uplift of Himalaya and Tibet is largely unknown mainly due to poor constrains on Cenozoic evolution of monsoon. Previous attempts to reach consensus on past ISM intensity is hindered by lack of continuous sedimentary sequences and robust proxies. This project, eISM, will address these shortcomings by (a) utilising newly drilled sediment sequences from three sites in the Bay of Bengal and Andaman Sea, one of the core regions of ISM precipitation, through International Ocean Discovery Programme (IODP) expedition 353 and (b) applying tested proxies for salinity (oxygen isotope of seawater and Ba/Ca ratio from planktonic foraminifera) and erosional strength (from bulk elemental ratio) to reconstruct evolution of ISM precipitation. Monsoon records generated in eISM will help correlate with the increasingly well-constrained onshore tectonic history, in order to understand and quantify the impact of climate-modulated processes in controlling tectonic evolution on Earth.