In situ optical and microphysical properties of tropospheric aerosols in the Canadian High Arctic from 2016 to 2019

摘要: Abstract Since aerosols are an integral part of the Arctic climate system, understanding aerosol radiative properties and relation these to each other is important for constraining forcing effects in this remote region where measurements sparse. In situ size distribution, light scattering absorption were taken near Eureka (80.05oN, 86.42oW), on Ellesmere Island, Canadian High over three consecutive years provide insights into aerosols. During periods haze, we find that single albedo (SSA) at 405 nm generally higher more stable than determined 870 nm, with values ranging between 0.90–0.99 0.79–0.97, respectively. Events elevated coefficients ( B a b s ) exhibit Angstrom exponent (AAE) around 1 suggesting black carbon (BC) dominant absorbing measurement period. AAE close 2 occurring (SAE) 0 SAE below occasionally observed December indicate potential contribution from mineral dust late fall early winter. The apparent real imaginary parts complex refractive index have been found range 1.6–1.9 0.002–0.02, low component indicates very weak intrinsic compared BC-rich Systematic variabilities different optical microphysical depend strongly given wavelength. SSA shows strong inverse dependence , because correlates positively index. On hand, 870 nm coefficient c not due greater sensitivity ambient particle distribution scattering. Smaller particles prevalent during less polluted only weakly scatter leading lower when also low. Lastly, FLEXPART back-trajectories show correspond air masses which influenced by Eurasian Alaskan regions, including regions known BC emissions. This work emphasizes variability winter spring, likely changes source regions.