Extremes in the Concentrations of CCN at Mt. Musala and Synoptic Classifications

Abstract

According to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change the aerosols are having generally a negative but decreasing in magnitude contribution to the effective radiative forcing (ERF) and, therefore, they act against the global warming. Leading role in this ERF balance play the aerosols involved in aerosol-cloud interaction, named the cloud condensation nuclei (CCN). In the present article we study the distribution of CCN as monitored by the Basic Environmental Observatory Musala in 2016 and their performance in different atmospheric circulations. As first step, we determine the days with extrema in the concentration and sort them separately for minima and maxima using the circulation scheme of Jenkinson–Collison Types that comprises 26 types of circulations. Thus we determine the most frequent types of circulation occurring in the studied period. Consequently, for each of these days we obtain the backward trajectories using the Hybrid Single-particle Lagrangian Integrated Trajectory model. This permits to match the prevailing types of circulation with the origin of air masses, and, on the other hand, their origin with respect to prevailing height of the trajectory.