Aerosol and Trace Gas Composition and Source Apportionment in Two Coastal Cities: Houston, TX and San Diego, CA

MARIA ZAWADOWICZ, Mirtha Salatti, Chongai Kuang, Ashish Singh, Janek Uin, Ogochukwu Enekwizu, Arthur J. Sedlacek, Rebecca Trojanowski, Olga Mayol-Bracero, Brookhaven National Laboratory

     Abstract Number: 473
     Working Group: Coast to Coast Campaigns on Aerosols, Clouds, Chemistry, and Air Quality

Abstract
Coastal urban environments are a complex confluence of natural terrestrial and marine ecosystems and anthropogenic activities. At the same time, the coasts are where the greatest number of people, infrastructure, and ecological resources are in danger from global climate change. In this presentation, we will discuss the results from two recent coastal urban campaigns: the 2021–2022 TRacking Aerosol Convection interactions ExpeRiment (TRACER) in Houston, TX and the 2023–2024 Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) in San Diego, CA. Both of these campaigns used the aerosol instruments deployed as a part of the first Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF1), which include in-situ measurements of aerosol and trace gas chemistry, aerosol size distributions, optical properties and hygroscopicity, and atmospheric state and meteorology. We use the extensive aerosol characterization measurements together with the NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to source apportion the aerosol measured in Houston and San Diego. Using statistical techniques, including positive matrix factorization (PMF), hierarchical clustering and self-organizing maps (SOM), we sort the observed aerosol properties into regimes, which allow the description of comprehensive aerosol climatology in the two different coastal environments. We then compare the resulting climatologies and interpret them in the context of the local and regional meteorology.