Snowfall Rate Reduction by Pollution Aerosols

这项研究的假设是，人为气溶胶增加了云滴的浓度，但减小了云滴的平均尺寸，从而降低了下落的冰晶扫出过冷液滴的效率，从而降低了降雪率。这种方法是在风暴峰天文台监测云和气溶胶的化学和物理性质以及降雪率，风暴峰天文台是沙漠研究所运营的实验室，海拔3210米，靠近科罗拉多州的斯普林斯。在这个高度，在下雪期间，天文台经常位于云层上方。测量的量包括云滴、冰晶和气溶胶粒子的尺寸分布，云水和雪的化学成分，以及降雪率。雷达风廓线仪和气球探测系统通过提供风、温度、湿度、雷达反射率和多普勒谱的垂直剖面来补充地面测量。这项工作具有重大的经济和人口影响。如果污染的气溶胶显著降低降雪率，这将减少积雪中可用的水量，而积雪在西方是一个重要的来源。

The hypothesis of this research is that anthropogenic aerosols increase the concentration of cloud droplets but decrease their average size, thus reducing the snowfall rate by decreasing the efficiency with which falling ice crystals sweep out the supercooled droplets. The approach is to monitor the chemical and physical properties of clouds and aerosols and the snowfall rate at the Storm Peak Observatory, a laboratory operated by the Desert Research Institute at an elevation of 3210 meters near Steamboat Springs, Colorado. At this altitude, the Observatory is frequently above cloud base during snow. The measured quantities include the size distributions of cloud droplets, ice crystals, and aerosol particles, the chemical composition of cloud water and snow, and the snowfall rate. A radar wind profiler and balloon sounding system complement the measurements at the ground by providing vertical profiles of wind, temperature, humidity, radar reflectivity, and Doppler spectra. This work has significant economic and demographic implications. If pollution aerosols are significantly reducing snowfall rates, this will decrease the amount of water available from snow pack, which in the West is an important source.