Aerosols-Climate Interactions: Characterization of Saltation, Dust Lifting, and Dust Electrification in Important Dust Source Regions

气溶胶-气候相互作用：重要沙源区域盐化、扬尘和粉尘带电的特征

• 批准号: 1118467
• 负责人: Nilton Renno
• 金额: $ 62.6万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1118467&HistoricalAwards=false
• 关键词: Aerosols; Climate; Interactions; Characterization; Saltation

Aerosols produce a direct climate forcing by scattering and absorbing solar and infrared radiation, and an indirect forcing by altering cloud processes. Since human activity causes significant increases in the concentration of atmospheric aerosols, it is important to understand the effects of aerosols on climate. Despite considerable progress in our understanding of aerosols-climate interactions, climate forcing by mineral dust aerosols is still one of the most uncertain processes in current climate models (IPCC, 2007). Therefore, it is important to study the lifting and transport of dust aerosols so that aerosol climate forcing can be assessed accurately. Intellectual merits:Mineral dust aerosols are lifted (ejected into the atmosphere) by saltation and transported away from the surface by convective plumes (in particular, their updrafts), convective vortices (dust devils), dust storms (dust lifting by gust fronts), and large-scale winds (wind-blown dust). So far most research has focused on studies of dust lifting by large-scale processes such as dust storms and wind-blown dust because they are the most important contributors to the global aerosol budget. However, recent studies suggest that small-scale processes such as convective plumes and vortices also play an important role on the global mineral dust budget. This suggestion is consistent with evidence that variations in the annual dust cycle of West African dust "hot spots" are strongly correlated with variations in small-scale wind gusts produced by dry boundary layer convection, but not with variations in the mean surface wind.In order to fully understand aerosols-climate interactions we must understand the basic physical processes involved in saltation and their variability with soil and weather conditions. This project will achieve this goal by studying saltation and dust lifting in Nevada, an area where small-scale dust lifting processes are ubiquitous, the Owens Dry Lake, one of the most important dust source areas in the U.S.Broader impacts:The research has the potential to have a broad impact on science and society. Besides studying an important scientific problem key to our understanding of global climate change, we will make our data and models available to the scientific community. We have an educational website that provides simple physical explanations for the formation of convective plumes, dust devils, and dust storms. The website will include descriptions of the weather and climate of Nevada, the Owens Dry Lake. Finally, this project will contribute to the training of graduate students.

气溶胶通过散射和吸收太阳辐射和红外辐射产生直接的气候强迫，并通过改变云的过程产生间接强迫。由于人类活动导致大气气溶胶浓度显著增加，因此了解气溶胶对气候的影响非常重要。 尽管我们对气溶胶-气候相互作用的理解取得了相当大的进展，但矿物粉尘气溶胶的气候强迫仍然是当前气候模型中最不确定的过程之一（IPCC，2007）。因此，研究沙尘气溶胶的抬升和输送对准确评估气溶胶气候强迫具有重要意义。智力优势：矿物尘埃气溶胶通过跃移被抬升（喷射到大气中），并通过对流羽流（特别是它们的上升气流）、对流涡旋（尘暴）、沙尘暴（阵风锋抬升尘埃）和大尺度风（风吹尘埃）被带离地表。 到目前为止，大多数研究都集中在对沙尘暴和风吹尘埃等大规模过程引起的尘埃上升的研究上，因为它们是全球气溶胶收支的最重要贡献者。 然而，最近的研究表明，对流羽流和涡旋等小尺度过程也对全球矿物尘埃收支起着重要作用。 这一建议是一致的证据表明，在每年的灰尘周期的西非灰尘“热点”的变化与小规模的阵风干边界层对流产生的变化，但不与平均地面wind. To充分了解气溶胶气候相互作用的变化，我们必须了解的基本物理过程中涉及的跃变和土壤和天气条件的变化。 该项目将通过研究内华达州的跃移和扬尘来实现这一目标。内华达州是一个小规模扬尘过程普遍存在的地区，欧文斯干湖是美国最重要的扬尘源地区之一。 除了研究一个对我们理解全球气候变化至关重要的科学问题外，我们还将向科学界提供我们的数据和模型。 我们有一个教育网站，为对流羽流、尘暴和沙尘暴的形成提供简单的物理解释。 该网站将包括对内华达州欧文斯干湖的天气和气候的描述。最后，本项目将有助于研究生的培养。