Light-absorbing impurities such as mineral dust can play a major role in
reducing the albedo of snow surfaces. Particularly in spring, deposited
dust particles lead to increased snow melt and trigger further feedbacks
at the land surface and in the atmosphere. Quantifying the extent of
dust-induced variations is difficult due to the high variability in the
spatial distribution of mineral dust and snow. We present an extension
of a fully coupled atmospheric and land surface model system to address
the impact of mineral dust on the snow albedo across Eurasia. We
evaluated the short-term effects of Saharan dust in a case study. To
obtain robust results, we performed an ensemble simulation followed by
statistical analysis. Mountainous regions showed a strong impact of dust
deposition on snow depth. We found a mean significant reduction of -1.4
cm in the Caucasus Mountains after one week. However, areas with flat
terrain near the snow line also showed strong effects despite lower dust
concentrations. Here, the feedback to dust deposition was more
pronounced as increase in surface temperature and air temperature. In
the region surrounding the snow line, we found an average significant
surface warming of 0.9 K after one week. This study shows that the
impact of mineral dust deposition depends on several factors. Primarily,
these are altitude, slope, snow depth, and snow cover fraction.
Especially in complex terrain, it is therefore necessary to use fully
coupled models to investigate the effects of mineral dust on snow pack
and the atmosphere.