Abstract View
Water Uptake of Atmospheric Organosulfates at Sub and Supersaturated Conditions
Chao Peng, Patricia Razafindrambinina, KOTIBA A. MALEK, Lanxiadi Chen, Weigang Wang, Rujin Huang, Yuqing Zhang, Xiang Ding, Maofa Ge, Xinming Wang, Akua Asa-Awuku, Mingjin Tang, University of Maryland
Abstract Number: 7
Working Group: Aerosols, Clouds and Climate
Abstract
Organosulfates (OS) are ubiquitous in the atmosphere, but their role in atmospheric chemistry and physics is poorly understood. Hence, exploring the water uptake extent of OSs can improve our understanding of their, dry and wet deposition, and impact on cloud formation. In this study, the subsaturated and supersaturated droplet growth of four atmospherically relevant OSs: sodium methyl sulfate (methyl-OS), sodium ethyl sulfate (ethyl-OS), and sodium octyl sulfate (octyl-OS) were investigated. The droplet activation is measured with a cloud condensation nuclei counter (CCNC) at supersaturated conditions (SS; 0.4, 0.6, 0.8, and 1.0%). The hygroscopic growth, under subsaturated conditions, of these aerosolized chemicals were studied using a vapor sorption analyzer and a humidity tandem differential mobility analyzer (H-TDMA). Results show that supersaturated hygroscopicity derived from κ -Köhler theory analysis can be larger than sub-saturated hygroscopicity. κ-values range from 0.2 to 0.5 and vary with supersaturation. The organosulfate solubility limit and droplet surface tension depression play an important role in determining droplet activation at supersaturated regimes.