Dynamic and chemical controls on new particle formation occurrence and characteristics from in situ and satellite-based measurements

We analyze the association between satellite-based measurements of chemical conditions (sulfur dioxide (SO2), nitrogen dioxide (NO2), and formaldehyde (HCHO) concentrations), insolation (UV), and aerosol particle properties (aerosol optical depth (AOD) and Ångström exponent (AE)); and the occurrence of new particle formation (NPF), formation rates (J6), growth rates (GR), and survival probabilities (SP) using particle size distribution measurements taken during two extended field campaigns at a forested location in southern Indiana. When conditionally sampled by event occurrence and non-occurrence the satellite-derived parameters exhibit significant differences and also show some degree of skill in predicting NPF though logistic regression analysis. During leaf-on measurement periods, NPF occurrence exhibits strong seasonality (NPF is more frequent in spring vs. summer) and is associated with a low condensational sink, while leaf-off NPF occurrence is associated with high near-surface UV receipt. Multiple linear regression equations of J6, GR, and SP using the chemical conditions as predictors exhibit some significant r2 values (p < 0.1), but are relatively unstable and many of the regression coefficients do not differ significantly from zero.