Measurement and Modeling of Dust Emissions

粉尘排放的测量和建模

• 批准号: 9972960
• 负责人: Jack Gillies
• 金额: $ 18万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9972960&HistoricalAwards=false
• 关键词: Measurement; Modeling; Dust; Emissions

9972960GilliesThe emissions of dust sized mineral particles (50 micron diameter) from susceptible surfaces such as playas, alluvial fans, and washes in arid and semi-arid environments remains poorly understood. Under certain wind conditions these surfaces provide a significant source of particulates that can result in high background atmospheric dust loadings, or in some cases, major dust storms. Dust can be entrained by the shearing force of the wind and also ejected from the surface into the air stream by the ballistic impact of sand grains moving in saltation. Models that consider only saltation bombardment and an unlimited supply of upwind sediment do not adequately explain observed dust emission relationships, data scatter notwithstanding. PIs are proposing a combined portable wind tunnel and tower monitoring field study to quantify in situ the horizontal and vertical fluxes of coarse and fine particles as a function of wind parameters and surface characteristics. The collected database will also allow them to test the performance of three dust emission models that have been described in the literature with dust emission and surface characterization measurements. This knowledge is essential for revising or improving models that describe the emission process. A model that can accurately characterize dust entrainment rates and vertical flux is a practical necessity for predicting soil loss due to wind erosion and for estimating relative source contributions of mineral aerosols to the atmosphere.

9972960 Gillies在干旱和半干旱环境中，从易受影响的表面（如干盐湖、冲积扇和冲刷）排放的粉尘大小的矿物颗粒（直径50微米）仍然知之甚少。 在某些风力条件下，这些表面提供了一个重要的颗粒源，可导致高背景大气粉尘负荷，或在某些情况下，重大沙尘暴。灰尘可以被风的剪切力夹带，也可以通过跳跃运动的沙粒的弹道冲击从表面喷射到气流中。 只考虑跃移轰击和无限供应的逆风沉积物的模型不能充分解释观测到的粉尘排放关系，尽管数据分散。 专业研究人员建议进行一项便携式风洞和塔监测相结合的实地研究，以现场量化粗细颗粒的水平和垂直通量，作为风参数和表面特征的函数。收集的数据库还将使他们能够测试文献中描述的三种粉尘排放模型的性能，并进行粉尘排放和表面表征测量。这种知识对于修订或改进描述排放过程的模型至关重要。 一个模型，可以准确地描述粉尘夹带率和垂直通量是一个实际的必要性，预测土壤流失，由于风蚀和估计相对源贡献的矿物气溶胶到大气中。