The Results of SAIL-Net: Investigating Spatial Variability of Aerosol and Cloud Nuclei in Mountainous Terrain

LEAH GIBSON, Ethan Emerson, Nicholas Good, Anna Hodshire, Ezra Levin, Gavin McMeeking, Kate Patterson, Bryan Rainwater, Tom Ramin, Benjamin Swanson, Handix Scientific

     Abstract Number: 7
     Working Group: Aerosols, Clouds and Climate

Abstract
In the Western United States and similar regions around the word, precipitation in the mountains plays a crucial role in local and downstream freshwater supplies. Atmospheric aerosols can significantly affect clouds and precipitation by acting as cloud condensation nuclei (CCN) and ice nucleating particles (INP). Gaining knowledge about the variability of atmospheric aerosols in mountainous areas provides valuable information for precipitation forecasting and understanding the impacts of aerosols on the hydrologic cycle. In fall of 2021, we deployed a novel network of miniaturized instrumentation in the East River Watershed near Crested Butte, Colorado, U.S. to contribute to the U.S. Department of Energy (DOE)-funded Surface Atmosphere Integrated Field Laboratory (SAIL). The goal was to better understand aerosol-cloud interactions in mountainous regions. SAIL had two measurement sites in this region, an ARM Mobile Facility (AMF2) and the Aerosol Observing System (AOS). In such complex topography, these two measurement sites could miss important regions of aerosol-cloud interactions. To expand the spread of SAIL measurements, we deployed SAIL-Net, a network of six aerosol measurement nodes spanning both the horizontal and vertical domain of the SAIL region. Each measurement node included a small particle counter (POPS) which counts particle number and sizes them between 140 nm - 2 um; a miniature cloud condensation nuclei counter (CloudPuck); and a filter sampler (IcePuck) for INP analysis. This project aimed to study three, interconnected topics: the spatial variability of aerosols, the temporal trends of aerosols, and the usefulness of dense networks in complex terrain to measure aerosol-cloud interactions. After the project’s completion in June 2023, we used the data to explore these areas and improve our understanding of aerosol variability in mountainous areas. We discuss the major insights from our data and analyze the utility of a dense measurement network in this region.