AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Investigating Different Salt Ions Impact on Cloud Condensation Nucleus (CCN) Activity of Black Carbon Aerosol
QI YAO, Howard Fairbrother, Alexa Wallace, Akua Asa-Awuku, University of Maryland
Abstract Number: 778 Working Group: Aerosols, Clouds and Climate
Abstract Black carbon (BC) particles are emitted into the atmosphere due to incomplete fossil fuel and biomass combustion. BC contributes to lower air quality, atmospheric warming, and regional cloud property modification. However, it is widely known that BC is insoluble and hydrophobic. Thus BC-cloud interactions have not been fully understood; these uncertainties contribute to large uncertainties in net climate prediction forcing from BC sources. Previous research has demonstrated that BC contributes to droplet formation and plays a role as cloud condensation nuclei (CCN) (mostly though models and field sampling experiments). In this study, systematic experiments have been designed to understand the potential impacts from different salt ions (Na+, K+, Mg2+, Cl-, SO42-) on BC aerosol CCN activity. CCN is quantified by the single hygroscopicity parameter (k). Results show that a significant increase in the water-uptake of BC aerosols after mixing with very low (< 0.0001 molar) amounts of salt ions. In addition, different salt ions present varying degrees of contribution to BC aerosol CCN activity growth. This study helps to understand the large hygroscopicity change of BC with the presence of small amounts of salt ions.