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

摘要 ATM-9709806 Miller, Gifford H. 科罗拉多大学博尔德分校 ATM-9714893 Fogel, Marilyn L. 卡内基华盛顿研究所 澳大利亚内陆干旱：米兰科维奇和澳大利亚季风艾尔湖盆地的人为强迫 艾尔湖盆地是一个季风控制的内陆盆地，覆盖澳大利亚大陆的六分之一。 该盆地观测到的大部分干湿循环都是由澳大利亚季风的米兰科维奇强迫来解释的。 尽管受到太阳辐射和海平面的强烈强迫，艾尔湖未能在全新世早期被填平，据推测，这是最早的人类移民系统燃烧的结果。 过去 50 年来，澳大利亚各地植被密度和组成的减少，可能导致季风对内陆的渗透显着减弱，长期趋势是干旱加剧。 为了进一步检验这一假设，该奖项支持实地、分析和建模研究：1) 使用平胸鸟蛋壳和其他脊椎动物的骨骼/牙齿中新记录的稳定同位素信号来评估澳大利亚北部过去 7 万年降水和植被组成的变化，2) 制定格雷戈里湖干湿循环年表，格雷戈里湖是一个完全位于季风浇灌地区的较小盆地，3) 完善通货紧缩年表艾尔湖盆地的事件，以更严格地评估与米兰科维奇控制的相关性，4）为古植被重建开发新的代理，5）完成敏感性测试，使用大气环流模型评估植被变化对季风降水渗透到艾尔湖盆地的作用。

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.