Impact of postglacial warming on tropical convection and precipitation patterns in the Indonesian Archipelago

本研究计划的主要目标是：（1）破译末次冰期循环期间澳大利亚-澳大利亚群岛的区域降水模式，特别强调海因里希事件和丹斯加德-奥施格事件、博林/阿勒罗德事件、新仙女木事件和全新世早期北方半球日射最大值期间的短暂变暖和变冷事件;（2）阐明在连续的气候变冷和变暖事件期间热带降雨变率的主要控制因素，以及（3）为了检验这样一个假设，即在热带变暖期间，热带对流的减少和步行者环流的减弱会导致空间复杂的降水模式，而不是在该地区均匀降雨增加。为了实现这些目标，我们建议重建的陆源径流从婆罗洲，苏拉威西岛，爪哇岛和孙达兰到马卡萨尔海峡，南部西里伯斯海和弗洛雷斯海的年代久远的沉积物档案，定位，以覆盖大流域的主要河流三角洲。我们将结合XRF扫描仪获得的高分辨率地球化学记录与海洋表面温度和盐度估计，基于Mg/Ca和δ 18 O测量的浮游有孔虫Globigerinoides ruber。我们的重建将提供一个重要的区域数据库和一个强大的框架，以测试与未来全球气候变暖相关的降水变化的建模预测。

The primary objectives of this research proposal are (1) to decipher regional precipitation patterns across the Indonesian-Australian archipelago during the last glacial cycle with specific emphasis on transient warming and cooling episodes during Heinrich and Dansgaard-Oeschger Events, the Bølling/Allerød, Younger Dryas and early Holocene northern hemisphere insolation maximum, (2) to elucidate primary controls of tropical rainfall variability during successive climate cooling and warming episodes, and (3) to test the hypothesis that a reduction in tropical convection and weakening of the Walker circulation during tropical warming results in a spatially complex precipitation pattern rather than a uniform rainfall increase over the region. To achieve these objectives we propose to reconstruct the terrigenous runoff from Borneo, Sulawesi, Java and Sundaland into the Makassar Strait, southern Celebes Sea and Flores Sea in well dated sediment archives, positioned to cover large catchment areas from major river deltas. We will integrate XRF-scanner derived high resolution geochemical records with sea surface temperature and salinity estimates, based on Mg/Ca and δ18O measurements of the planktonic foraminifer Globigerinoides ruber. Our reconstruction will provide an essential regional database and a robust framework to test modeling predictions of precipitation change associated with future global climate warming.