Winds of Change: Exploring the Meteorological Drivers of Global Dust

变革之风：探索全球沙尘的气象驱动因素

• 批准号: 2333139
• 负责人: Amato Evan
• 金额: $ 80.06万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-15 至 2027-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2333139&HistoricalAwards=false
• 关键词: Winds; Change; Exploring; Meteorological; Drivers

Mineral dust kicked up from dry land accounts for a remarkably large portion of the particulate matter in the air, by some estimates as much as two thirds of the global particulate aerosol burden. One reason for the dustiness of the atmosphere is that atmospheric dust concentration has increased dramatically since the Industrial Revolution, possibly due to the expansion of cleared, tilled, agricultural land. The prominence of dust as an atmospheric aerosol and its dramatic increase over time motivate research on its climatic effects, among them cooling by reflecting sunlight back to space, warming by trapping outgoing infrared radiation, and indirect effects due to the influence of dust on clouds. But such research is complicated by the fact that mineral dust enters the atmosphere when strong winds blow over dry soil, thus extreme wind events occurring sporadically and over small areas can make an outsized contribution to the global burden. The prominence of small-scale extreme events challenges efforts to understand the role of dust in the climate system, especially efforts that rely on long simulations of global climate models which lack the resolution and dynamical sophistication needed to capture small-scale windstorms.Research under this award considers the role of two types of wind events in global dust emissions: downslope windstorms in mountainous regions and haboobs, strong straight-line wind events caused by the downbursts of collapsing thunderstorms. Both types of wind events are associated with strong dust emissions and both are driven by small-scale dynamics that are not captured by current global climate models. The project takes advantage of 40-day simulations of the Model for Predication Across Scales (MPAS), which has the fine-scale resolution (3.75km grid spacing) and more sophisticated dynamics needed for downslope windstorms and haboobs. The surface winds from the MPAS simulations are taken as inputs to an offline dust emission model to determine the amount of dust emitted by these events. A second line of research adjusts a state-of-the-art climate model, the Community Earth System Model version (CESM), to replicate the dust generated in the offline dust emission experiments. The CESM simulations are "nudged" to conform to observed atmospheric circulation so that the dust aerosol concentration and its climate effects can be compared against real-world measurements.The work is of societal as well as scientific interest given the potential climatic effects of airborne dust, the large uncertainty as to those effects, and the extent to which human activity could cause large changes in dust concentration. The dustiness of the atmosphere has other effects, for instance it reduces air quality but it also provides a source of iron and other nutrients for marine ecosystems. The project also includes a collaboration with the San Diego County Office of Education to develop teaching activities for California high school science teachers. In addition, the project provides support and training to a graduate student and a postdoc, thereby providing for the future workforce in this research area.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

矿物灰尘从干燥的土地上踢起来，占空气中颗粒物的很大一部分，估计多达三分之二的全球颗粒物气溶胶负担。 大气尘土飞扬的原因之一是，自工业革命以来，大气中的灰尘集中量显着增加，这可能是由于清除，耕种的农业用地的扩大。 尘埃作为一种大气气溶胶的突出性以及随着时间的推移的急剧增长激发了对其气候影响的研究，其中包括通过将阳光回到太空，通过捕获发出的红外辐射来变暖，以及由于灰尘对云对云对云的影响而引起的间接影响。 但是，当强风在干燥的土壤上吹来时，矿物灰尘进入大气使这一研究变得复杂，因此，极端风事件偶尔发生，而在小区域上发生的极端风能可以为全球负担做出巨大的贡献。 The prominence of small-scale extreme events challenges efforts to understand the role of dust in the climate system, especially efforts that rely on long simulations of global climate models which lack the resolution and dynamical sophistication needed to capture small-scale windstorms.Research under this award considers the role of two types of wind events in global dust emissions: downslope windstorms in mountainous regions and haboobs, strong straight-line wind events caused by the downbursts of崩溃的雷暴。 两种类型的风事件都与强烈的灰尘排放有关，并且两者都是由当前全球气候模型捕获的小型动力学驱动的。 该项目利用了40天的模型跨量表（MPA）的模型，该模型具有精细的分辨率（3.75 km网格间距），并且对于下坡风暴和HABOBS所需的更复杂的动力学。 MPA模拟的表面风被视为输入离线灰尘发射模型，以确定这些事件发出的灰尘量。 第二条研究可以调整最先进的气候模型，即社区地球系统模型版本（CESM），以复制离线灰尘发射实验中产生的灰尘。 CESM模拟被“轻描淡写”，以符合观察到的大气循环，以便可以将尘埃气溶胶浓度及其气候效应与现实测量值进行比较。鉴于机源性粉尘的潜在气候效应，这些作用的巨大不确定性可能会导致人类活动的范围，以及在粉尘浓度中的大量变化，这项工作既具有社会和科学兴趣，又可以进行科学兴趣。 大气的灰尘还具有其他影响，例如，它降低了空气质量，但也为海洋生态系统提供了铁和其他营养的来源。 该项目还包括与圣地亚哥县教育办公室合作，为加利福尼亚高中科学教师开发教学活动。 此外，该项目为研究生和博士后提供了支持和培训，从而为该研究领域提供了未来的劳动力。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估审查标准的评估来获得支持的。