AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Wintertime New Particle Formation and Its Contribution to Cloud Condensation Nuclei in the Northeastern United States
FANGQUN YU, Gan Luo, Yanda Zhang, James Schwab, Joseph P. Marto, Lauriana C. Gaudet, Kara Sulia, The State University of New York at Albany
Abstract Number: 700 Working Group: Aerosols, Clouds and Climate
Abstract Particle number concentration is an important factor affecting the health and climate impacts of atmospheric aerosols. For example, high number concentrations of ultrafine particles may lead to adverse health effects. Atmospheric particles act as cloud condensation nuclei (CCN) and modify cloud properties and precipitation and thus indirectly impact the hydrological cycle and climate. New particle formation (NPF), frequently observed at various locations around the globe, is an important source of ultrafine particles and CCN in the atmosphere. In this study, wintertime particle formation over the northeastern United States (NEUS) is simulated with WRF-Chem coupled with a size-resolved (sectional) advanced particle microphysics (APM) model. Model simulated variations of meteorology, aerosol precursors, and particle number concentrations agree well with corresponding measurements taken at Pinnacle State Park, NY. We show that even during wintertime, regional nucleation occurs and contributes significantly to ultrafine particle and CCN number concentration in NEUS. Due to low biogenic emissions, wintertime regional nucleation is solely controlled by inorganic species and the newly developed ternary ion-mediated nucleation is able to capture the variations of observed particle number concentrations (ranging from ~ 200 – 20,000 cm-3). Sulfuric acid, ionization and ammonia are major parameters controlling NPF in the NEUS wintertime, which contributes to more than 90% of total particle number concentrations and ~ 50% of CCN and cloud droplet number concentrations. The impact of NPF on cloud and ice water content and precipitation will also be discussed.