An analysis of fog and low stratus life-cycle regimes over central Europe

A better understanding of fog and low stratus (FLS) life cycles, in particular the typical onset and dissipation times, can help traffic safety and solar power planning. Besides its high dependence on the prevalent meteorological conditions, the FLS life cycle is further determined by the FLS type as well as the underlying geography and climate. While satellite-based FLS data sets with high temporal and spatial resolution are available, an objective, large-scale, satellite-based classification of FLS life-cycle regions, which would allow for more targeted analyses of the FLS life cycle, is lacking. In this study, a hierarchical clustering algorithm is applied to identify regions of similar relationships of the FLS life cycle to environmental conditions over central Europe. The clustering reveals major FLS life-cycle regimes with distinct differences in FLS occurrence, temporal FLS life-cycle patterns, and climatic characteristics. Based on regime-specific sensitivity analyses, the relationships of the FLS life cycle with near-ground temperature and specific humidity are identified as the most relevant input relationships for the clustering algorithm, especially in the Mediterranean region. FLS life-cycle regimes are further presented at a regional scale, outlining the applicability of the derived FLS life-cycle regimes to future regional process-oriented FLS life-cycle studies. In this study, a hierarchical clustering algorithm is used to identify regions of similar relationships of the FLS life cycle to environmental conditions over central Europe. The clustering reveals major FLS regimes with distinct differences in FLS occurrence, temporal FLS life-cycle patterns, and climatic characteristics. Near-ground temperature and specific humidity are identified as the most relevant input relationships for the clustering algorithm. The identified FLS regimes can be used further for regional process-oriented FLS life-cycle studies. image