AGS-PRF: Estimating the Dust Climate Feedback by Developing and Using an Improved Parameterization of Dust Aerosol Emission

该奖项为项目负责人提供为期2年的博士后研究奖学金，项目负责人将在康奈尔大学Natalie Mahowald教授的指导下工作。在博士后研究奖学金期间，PI将开发和评价主要来自沙漠和半干旱地区的尘埃排放的物理参数化。参数化是基于跃变过程和玻璃等脆性材料的破碎之间的形式等价。跃变过程是由于弹跳沙粒的冲击而从地表喷出的粉尘气溶胶。该项目主要有三个方面的任务：1)建立一个改进的沙尘排放参数化，该参数化严格考虑了侵蚀土壤释放的沙尘通量对风速、土壤性质和植被的依赖；2)在NCAR社区地球系统模型（CESM）中实现沙尘排放参数化，并利用当前沙尘周期的模拟进一步评估基于地面和卫星测量的参数化；3)利用沙尘模块量化从工业化前气候到现代气候，以及从现代气候到二氧化碳浓度上升到工业化前两倍的未来气候的沙尘气候反馈。由于沙尘在地球气候的形成中起着重要的作用，而沙尘的辐射效应可能是气候变化的重要反馈，因此这项工作将具有更广泛的实际和科学影响。因此，在气候和天气模式中更好地表示粉尘排放可能导致更好的气候和天气预测。此外，沙尘排放在云的形成、干旱物理和大气化学中也起着重要的作用，在大气模式中更好地表达沙尘排放将加强这些领域的研究。最后，博士后研究奖学金，在一个有成就的科学家的指导下，将有助于建立PI的职业生涯，从而为该科学学科的未来劳动力提供支持。

This award provides funds for a 2-year Postdoctoral Research Fellowship for the PI, who will work under the mentorship of Professor Natalie Mahowald at Cornell University. During the Postdoctoral Research Fellowship the PI will develop and evaluate a physically-based parameterization of the emission of dust, primarily from deserts and semi-arid regions. The parameterization is based on a formal equivalence between the saltation process, through which dust aerosols are ejected from the surface as a result of impacts with bouncing sand grains, and the fragmentation of brittle materials such as glass. The project has three broad tasks: 1) Developing an improved dust emission parameterization that rigorously accounts for the dependence of the dust flux emitted by an eroding soil on wind speed, soil properties, and vegetation; 2) Implementing the dust emission parameterization into the NCAR Community Earth System Model (CESM), and using simulations of the present day dust cycle to further evaluate the parameterization against a wide range of ground-based and satellite measurements; and 3) Using the dust module to quantify the dust climate feedback in transitions from the preindustrial to the present day climate, and from the present day to a future climate in which carbon dioxide concentrations rise to twice their pre-industrial values.The work will have broader impacts both practically and scientifically, as dust plays an important role in establishing the earth's climate, and the radiative effects of dust may constitute an important feedback for climate change. Thus, better representation of dust emission in climate and weather models may lead to better climate and weather predictions. In addition, dust emission plays an important role in cloud formation, drought physics, and atmospheric chemistry, and research in all these fields would be enhanced by better representation of dust emission in atmospheric models. Finally, the postdoctoral research fellowship, under the mentorship of an established scientist, will help to build the career of the PI, thereby providing support for the future workforce in this scientific discipline.