Raw Optical Particle Counter (OPC) Data for 3.3 and 6.3 meters off ground in ’A’ą̈y Chù’ Valley in Yukon, Canada Late Spring Early Summer 2021

GPS coordinates of sampling site are: 60°59'55.25"N, 138°31'24.05"W Two Multichannel Optical Particle Counters (OPC; Fast-Response Multichannel Monitor, FAI Instruments) were used to measure the size distribution and concentrations of the PM during the campaign. Particles of diameters between 0.28 and 10 µm were measured at an initial time resolution of 4 Hz and a flow rate of 1 L min−1.

Dilution with filtered air at a 6:1 ratio was used to avoid saturation of the detector during dusty periods.