Airborne Measurements of the Physio-Chemistry and Evolution of Aerosols in the Tropics during the Pacific Atmospheric Sulfur Experiment (PASE)

University Of Hawaii, Honolulu

Investigators

Abstract

This project involves deployment of a large suite of instruments to characterize aerosol physical, chemical, and optical properties in the Pacific Atmospheric Sulfur Experiment (PASE). These measurements are essential to understanding the sulfur cycle and its link to cloud condensation nuclei (CCN) in the marine boundary layer (MBL), and will lead to improved knowledge of the formation, transport, and removal of MBL aerosol and its role in the marine sulfur cycle. The primary objective in this work is to quantify links between MBL sulfur chemistry and changes in aerosol concentrations, size, and chemistry. Ambient non sea-salt and sea-salt aerosol surface areas needed to evaluate the uptake of gas phase species will also be determined. Aerosol hygroscopic growth is an important element in this project, and it will be constrained through measurements of size, chemistry, and humidity dependent growth. Other goals include the investigation of aerosol dynamics and growth in response to the diurnal photochemistry to be studied during PASE. Data on entrainment rates and vertical fluxes above and below the inversion and in the buffer layer (BuL) and MBL will be used to evaluate the role of these processes in modulating CCN concentrations in the MBL. This will include assessing the locations and significance of new particle formation. Finally, a time-of-flight aerosol mass spectrometer (TOF-AMS) will be deployed to provide fast size-resolved chemistry data (on both ionic and organic material) that can be applied to all of these issues. In conjunction with other measurements on PASE, these size-resolved effects will be linked to gas phase chemical sources, total aerosol chemistry, and associated variability in measured CCN spectra. Broader impacts of this project include the integration of research and education through involvement of graduate students and post-doctoral researchers in all stages of the field campaign from measurements to publications. Final data will reside in the PASE archive, which will be available to the broader community.