Influence of the Atmospheric Aerosol on Snowfall Scavenging Efficiencies and Precipitation Rates

科罗拉多州西北部一个山顶地区的气溶胶清除、降雨率和降雪云效率的研究将继续进行。将分析对气溶胶粒子、云滴和冰粒随大小的变化而进行的云内测量，以及先前所做的云凝结核(CCN)光谱，以确定降水云的三种水成分：冰、水和水蒸气之间的化学物种分布。通过这些测量，将评估自然和人为气溶胶粒子的不同种群对气溶胶粒子清除和降水过程的影响。由于主要的大气气溶胶CCN粒子源(自然和人为)的变化，云滴尺寸分布的变化将与两个主要的冰粒增长过程有关：液滴的积累和水汽的扩散。云内气溶胶和水团清除机制和速率的这些变化将被用来确定大气气溶胶浓度的变化如何影响云的微结构、污染物清除和降雪率。

Studies of aerosol scavenging and precipitation rates and efficiencies in snowing clouds at a mountaintop site in northwestern Colorado will continue. In-cloud measurements of aerosol particles, cloud droplets and ice particles as a function of size, and cloud condensation nuclei (CCN) spectra previously made will be analyzed to determine the distribution of chemical species among the three water components of a precipitating cloud: ice, water and vapor. From these measurements, the effect of varying populations of natural and anthropogenic aerosol particles on aerosol particle scavenging and precipitation processes will be assessed. Variations in the cloud droplet size distribution as a result of changes in the dominant atmospheric aerosol CCN particle source (natural versus anthropogenic)will be related to the two primary ice particle growth processes: accretion of droplets versus diffusion of water vapor. These variations in the in-cloud aerosol and water mass removal mechanisms and rates will be used to determine how changes in atmospheric aerosol concentrations effect cloud microstructure, pollutant scavenging and snowfall rates.