Drought in the Australian Outback: Milankovitch and Anthropogenic Forcing of the Australian Monsoon

摘要ATM-9709806米勒，吉福德H。 科罗拉多大学 Fogel，Marilyn L. 华盛顿卡内基学院 澳大利亚内陆的干旱：米兰科维奇和澳大利亚季风的人为强迫 艾尔湖盆地（Lake Eyre Basin）是一个受季风控制的内陆盆地，面积占澳大利亚大陆的六分之一。 大部分观察到的干湿循环的这个盆地的解释Milankovitch迫使澳大利亚季风。 尽管受到太阳辐射和海平面的强烈影响，但在全新世早期，艾尔湖未能填满，这被假设为最早的人类移民系统性燃烧的结果。 在过去的50万年，澳大利亚各地的植被的密度和组成的减少，可能导致了显着减弱的季风渗透到内地的长期趋势增加干旱。 为了进一步验证这一假设，该奖项支持实地，分析和建模研究1）使用新记录的稳定同位素信号在平胸蛋壳和其他脊椎动物的骨骼/牙齿，以评估在过去7万年的降水和植被组成的变化在澳大利亚北部北方，2）开发一个在格雷戈里湖的干湿循环年表，一个较小的盆地完全在季风浇灌区，3）完善在爱湖盆地通货紧缩事件的年表，以更严格地评估相关米兰科维奇控制，（4）开发新的古植被恢复指标;完整的敏感性测试评估的作用，植被变化的季风降水渗透到湖艾尔盆地使用大气环流模式。

Abstract ATM-9709806 Miller, Gifford H. University of Colorado, Boulder ATM-9714893 Fogel, Marilyn L. Carnegie Institute of Washington Drought in the Australian Outback: Milankovitch and Anthropogenic Forcing of the Australian Monsoon Lake Eyre Basin is a monsoon-controlled interior basin covering one-sixth of the Australian continent. A majority of the observed wet and dry cycles of this basin are explained by Milankovitch forcing of the Australian monsoon. The failure of Lake Eyre to fill in the early Holocene despite strong forcing by solar radiation and sea level is hypothesized to be a consequence of systematic burning by the earliest human immigrants. A reduction in the density and composition of vegetation across Australia in the past 50 ka, may have resulted in a significant weakening of monsoon penetration into the interior with a long-term trend towards increased aridity. To test this hypothesis further, this award supports field, analytical, and modeling studies 1) to use newly documented stable-isotope signals in ratite eggshell and bone/teeth of other vertebrates to evaluate changes in precipitation and vegetation composition over the past 70,000 years across northern Australia, 2) to develop a chronology for wet and dry cycles in Lake Gregory, a smaller basin wholly within the monsoon-watered region, 3) to refine the chronology of deflationary events in the Lake Eyre Basin to more rigorously evaluate the correlation to Milankovitch controls, 4) to develop new proxies for paleovegetational reconstructions and 5) complete sensitivity tests evaluating the role of vegetation change on the penetration of monsoon precipitation into the Lake Eyre Basin using General Circulation Models.