Black Carbon Aerosol Characteristics and Aerosol-Cloud Interactions near the Coast of Southern California
DONGLI WANG, Bradley Ries, Minghao Han, Alexander B. MacDonald, Mason Leandro, Sierra Bollinger, Lisa Welp-Smith, Roya Bahreini, Anthony Bucholtz, Patrick Chuang, Mikael Witte, Don Collins, Andrew Metcalf, Clemson University
Abstract Number: 318
Working Group: Coast to Coast Campaigns on Aerosols, Clouds, Chemistry, and Air Quality
Abstract
This study characterizes the nature of black carbon (BC) aerosols over the northeastern Pacific Ocean and investigates the interactions between BC particles and the marine atmosphere, including the persistent stratocumulus. The data are from a suite of aerosol and cloud instruments onboard the Navy Twin Otter aircraft, which conducted 21 flight observations near San Diego, CA in June 2023 as part of the SCILLA field campaign in coordination with the EPCAPE campaign. A Counter-flow Virtual Impactor (CVI) inlet was used to sample cloud residuals and an isokinetic inlet was used to sample cloud-free particles. A Scanning Electrical Mobility Spectrometer (SEMS) was used to measure the total submicron aerosol size distributions. A Single Particle Soot Photometer (SP2) was employed as the primary measurement of BC aerosol, while a mini Aerosol Mass Spectrometer (mAMS) measured non-refractory aerosol composition. Various wing-mounted cloud probes characterized the cloud droplet number concentrations and size distributions.
In this presentation, we examine two flights focused on the outflow region of Los Angeles with limited cloud cover and two flights near San Clemente Island with persistent stratocumulus. The mass concentration, size distributions, and mixing state of BC aerosols in cloud droplet residuals and cloud-free air are compared to analyze the interactions between BC aerosol and cloud droplets. These aerosol properties are also used to understand the influence that Los Angeles outflow has on the regional cloud cover. Detailed characterization of aerosols and clouds will help to understand the connection between BC aerosol and cloud properties to evaluate their impact on the marine environment.