Figure S1. Contour plots (left) show time series of aerosol number size distributions between 10 – 1000 nm from combined nSMPS and UHSAS measurements from aircraft measurements in and out of six active smoke plumes. Size distributions were used to calculate total number concentrations (Ntot) over the entire size range as well as geometric mean diameters (Dgn) for the accumulation mode (~40 – 1000nm). Scatter plots show Ntot for each plume pass (center) as well as accumulation mode Dgn as a function of estimated plume age (right). Measurements made during RF4 and RF15 showed a bimodal distribution. For these fires, the fraction of aerosol number in the fine mode (ffine) is also shown in red on right.