Since aerosols are an integral part of the Arctic climate system, understanding aerosol radiative properties and the relation of these properties to each other is important for constraining aerosol radiative forcing effects in this remote region where measurements are sparse. In situ measurements of aerosol size distribution, aerosol light scattering and absorption were taken near Eureka (80.05^oN, 86.42^oW), on Ellesmere Island, in the Canadian High Arctic over three consecutive years to provide insights into radiative properties of Arctic aerosols.

During periods of Arctic haze, we find that the single scattering albedo (SSA) at 405 nm is generally higher and more stable than that determined at 870 nm, with values ranging between 0.90–0.99 and 0.79–0.97, respectively. Events with elevated absorption coefficients ($B_{abs}$) exhibit generally an absorption Ångström exponent (AAE) of around 1 suggesting that black carbon (BC) is the dominant absorbing aerosol for the measurement period. AAE values close to 2 occurring with scattering Ångström exponent (SAE) values near 0 and SAE values below 0 occasionally observed in December indicate a potential contribution from mineral dust aerosols in late fall and early winter. The apparent real and imaginary parts of the complex refractive index at 405 nm have been found to range between 1.6–1.9 and 0.002–0.02, respectively. The low imaginary component indicates very weak intrinsic absorption compared to BC-rich aerosols.

Systematic variabilities between different aerosol optical and microphysical properties depend strongly on the given wavelength. SSA at 405 nm shows a strong inverse dependence with $B_{abs}$, because $B_{abs}$ correlates positively with the imaginary component of the refractive index. On the other hand, SSA at 870 nm correlates with scattering coefficient ($B_{sca}$) and not with $B_{abs}$ due to a greater sensitivity to the ambient particle size distribution for 870 nm scattering. Smaller particles with higher SAE that are prevalent during less polluted periods only weakly scatter at 870 nm leading to lower SSA when $B_{sca}$ is also low.

Lastly, FLEXPART back-trajectories show that lower aerosol SSA and higher $B_{abs}$ correspond to air masses which are more influenced by Eurasian and Alaskan regions, including regions known to have important BC emissions. This work emphasizes the important variability in Arctic aerosol optical properties during winter and spring, which is likely due to changes in source regions.

由于气溶胶是北极气候系统的组成部分，因此了解气溶胶辐射特性以及这些特性之间的关系对于限制稀疏测量的偏远地区的气溶胶辐射强迫效应至关重要。在气溶胶粒径分布的原位测量中，连续三年对加拿大高北极圈Ellesmere岛的Eureka（80.05 ^o N，86.42 ^o W）附近进行了气溶胶光的散射和吸收，以了解北极气溶胶的辐射特性。

在北极霾期间，我们发现在405 nm处的单散射反照率（SSA）通常比在870 nm处确定的更高并且更稳定，其值分别在0.90-0.99和0.79-0.97之间。吸收系数升高的事件（${乙}_{\mathrm{一种}bs}$）的吸收Ångström指数（AAE）通常约为1，表明黑碳（BC）是整个测量期间的主要吸收气溶胶。在12月偶尔观察到AAE值接近2且散射Ångström指数（SAE）值接近0且SAE值低于0的情况，这表明秋末和初冬矿物粉尘气溶胶的潜在作用。已发现在405 nm处，复数折射率的表观实部和虚部分别在1.6-1.9和0.002-0.02之间。与富含BC的气溶胶相比，虚构分量低表明其固有吸收非常弱。

不同气溶胶光学和微物理特性之间的系统差异在很大程度上取决于给定的波长。405 nm处的SSA与${乙}_{\mathrm{一种}bs}$， 因为 ${乙}_{\mathrm{一种}bs}$与折射率的虚部呈正相关。另一方面，在870 nm处的SSA与散射系数（${乙}_{sC\mathrm{一种}}$），而不是 ${乙}_{\mathrm{一种}bs}$由于对870 nm散射的环境粒径分布具有更高的灵敏度。SAE较高的较小颗粒在污染较少的时期普遍存在，仅在870 nm处弱散射，导致${乙}_{sC\mathrm{一种}}$ 也很低

最后，FLEXPART的反向轨迹表明，较低的气溶胶SSA和较高的气溶胶 ${乙}_{\mathrm{一种}bs}$对应于受欧亚和阿拉斯加地区（包括已知具有重要不列颠哥伦比亚省排放量的地区）影响更大的空气质量。这项工作强调了冬季和春季北极气溶胶光学特性的重要变化，这很可能是源区域的变化所致。