Investigating spatial variability of aerosol, cloud condensation nuclei, and ice nucleating particles in mountainous terrain

Abstract

Particles in the air, called aerosols, can have large impacts on clouds and precipitation by serving as cloud condensation nuclei (CCN) and ice nucleating particles (INP). Understanding the impacts of particles is critical to improving the predictability of the hydrologic cycle, especially in the western United States and other regions globally where mountain precipitation is critical to water supplies. Our goal is to better understand physical processes, focusing on aerosol-cloud interactions, that occur in mountain regions by deploying a novel network of miniaturized instrumentation in a Colorado mountain valley. The measurements will take place during the Surface Atmosphere Integrated Field Laboratory (SAIL) campaign, which will be providing vital observations of cloud properties and precipitation, among other key measurements. Our instruments will include a small optical particle counter, a novel CCN counter, and a filter sampler to collect aerosols for subsequent INP analysis. We will collaborate with several SAIL investigators to better understand the impacts of aerosols on clouds during the study by linking our network of observations with complementary in situ measurements, remotely sensed cloud and aerosol properties, and modeling efforts. Our science goals are to (1) examine how vertical variations in aerosols and cloud nuclei affect clouds, (2) identify factors driving temporal and spatial variability in aerosols and cloud nuclei in mountainous terrain, and (3) examine effectiveness of a network-based approach to understanding complex aerosol-cloud interactions as this will be the first study of its kind to deploy this number and type of sensors in a relatively small study area. Benefits of the project include improved understanding of aerosol-cloud interactions in mountainous terrain, better predictability of the hydrologic cycle in this important terrain type with subsequent benefits to water resource planning, and assessment of a new approach for climate research.