Advancing Understanding of Super-Coarse and Giant Dust Particles via Novel Measurements of Emission and Transport

通过新颖的排放和传输测量方法增进对超粗和巨型灰尘颗粒的了解

• 批准号: 2336111
• 负责人: Amato Evan
• 金额: $ 70.21万
• 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: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2336111&HistoricalAwards=false
• 关键词: Advancing; Understanding; Super; Coarse; Giant; Advancing; Understanding; Super; Coarse; Giant

Dust storms are ubiquitous in Earth’s atmosphere and are composed of small mineral particles having diameters of varying sizes. Theory suggests that for dust transported long distances, the diameters of these particles should be limited to approximately 10 microns or smaller, due to the downward gravitational force acting to remove larger particles from the atmosphere. However, dust particles with diameters of tens to even hundreds of microns in size have been measured thousands of kilometers away from the deserts where they were lofted into the atmosphere. To-date, there is no accepted explanation for this so-called “giant dust particle conundrum”, highlighting a gap in physical understanding of atmospheric and aerosol processes. Since the magnitudes of dust storm effects on weather and climate, ranging from the absorption of sunlight to being a catalyst for biological activity in the oceans, depend on the physical characteristics of dust, including the particle sizes, there is a need to solve this conundrum. This project aims to improve understanding of the movement of dust particles having diameters greater than 10 microns (super coarse and giant particles, or SCG dust) in the atmosphere, and make progress towards solving the giant dust particle conundrum. Size-resolved changes in the concentrations of SCG dust during vertical diffusive and horizontal advective transport will be measured. Additionally, the size-resolved vertical flux of SCG dust at the point of emission will also be measured. These measurements will then be used to test two hypotheses that could explain the conundrum: (i) that current theory grossly overestimates dry deposition of these large particles during both vertical turbulent diffusive and horizontal advective transport and (ii) that the flux of SCG dust at emission is one to several orders of magnitude greater than that predicted by theory. These data will provide a unique opportunity to evaluate the theory governing the emission and atmospheric transport of these particles, and to generate new methods to represent these processes in weather and climate models.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.

沙尘暴在地球大气中无处不在，由大小不同的小矿物颗粒组成。理论表明，对于尘埃运输的长距离，由于向下重力作用以从大气中去除较大的颗粒，这些颗粒的直径应限制在大约10微米或更小的位置。但是，直径至甚至数百微米的尘埃颗粒已被测量，距离沙漠中数千公里，在那里它们被着是大气中的大气层。迄今为止，对于这种所谓的“巨大尘埃颗粒难题”，没有公认的解释，突显了对大气和气溶胶过程的物理理解的差距。由于沙尘暴对天气和气候的影响，从阳光的抽象到成为海洋生物学活性的催化剂，具体取决于包括灰尘的物理特征（包括颗粒尺寸），需要解决这种难题。该项目旨在提高对大气中直径大于10微米（超级珊瑚和巨型颗粒或SCG尘埃）的尘埃运动的理解，并在解决巨大的灰尘颗粒构成的方向上取得了进展。将测量垂直扩散和水平高级传输过程中SCG灰尘浓度的尺寸分辨变化。此外，还将测量SCG灰尘的尺寸分辨垂直通量在发射点。然后，这些测量结果将用于检验两个可以解释难题的假设：（i）在垂直湍流差分和水平活性运输过程中，当前的理论大量高估了这些大颗粒的干燥沉积，并且（ii）（ii）SCG粉尘在发射时的通量比通过理论预测的要大于几个阶段。这些数据将提供一个独特的机会，以评估管理这些颗粒的发射和大气传输的理论，并生成新的方法以在天气和气候模型中代表这些过程。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的审查标准来通过评估来通过评估来支持的。