EPCAPEOH

EPCAPE-OH Burst

1 March 2023 - 15 December 2023

Lead Scientist: Suzanne Paulson

Observatory: AMF (ARM Mobile Facility 1) - EPC

The DOE-funded Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) campaign will be conducted in La Jolla, California from February 2023 to January 2024, siting an array of cloud, aerosol, and precipitation instrumentation at the Scripps Pier and nearby Mt. Soledad. EPCAPE will provide unprecedented characterization of coastal clouds, their seasonal changes, and their diurnal evolution. We propose to augment these meteorological observations with a suite of advanced chemical measurements at Mt. Soledad to document the differences from the ARM instruments at the Scripps Pier and to collect in-cloud measurements of gas and droplet composition. Within this larger collaboration, which will leverage a large array of chemical and meteorological measurement data, we will collect samples both within and outside of clouds, measure their metal concentrations, and determine their ability to produce an OH burst. This unique opportunity to measure particles in clouds will allow us to better answer the question of how the ability of aerosol particles to generate hydroxyl radical (OH) “bursts” in clouds depends on their chemical composition, source, and cloud-processing history, and also to explore the impact of OH chemistry evident in the chemical composition of particles with different cloud-processing histories.