VOCALS: Airborne Measurements of Aerosol Dynamics and Evolution

University Of Hawaii, Honolulu

Investigators

Abstract

During the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) experiment, a suite of instruments will be deployed on the NSF/NCAR C-130 aircraft to measure a wide variety of aerosol properties: number, volatility, size distributions from 10 nm to 10 um in diameter, size-resolved aerosol composition, mixing state, and optical properties at low and ambient humidities. The data will be used to determine the origin of aerosol particles (from the sea surface, the free troposphere, or formed in situ), their suitability as cloud condensation nuclei (CCN), the mechanisms that control particle and CCN concentrations in pockets of open cells (POCs) and the VOCALS region, and their related optical properties. These measurements will help answer several of the hypotheses proposed in the overall VOCALS plan, including the role of aerosol properties in cloud and drizzle formation, scavenging, POC formation and the relationship between aerosol sources and cloud properties. Close collaborations will be established with other aerosol scientists on the C-130 and other platforms during VOCALS, as well as with cloud physicists, meteorologists and remote sensing specialists. The data should lead to improved understanding of the processes controlling aerosol effects on the radiative balance and climate in regions with extensive stratocumulus cloud cover. This will enable modelers to better parameterize those processes and will also help in understanding the impacts of large anthropogenic sulfur dioxide (SO2) and aerosol sources along the coast of Chile. The results could potentially be applied to the study of CCN evolution and the aerosol indirect effects on cloud properties. One graduate student will be involved in the experiment and data analysis.