Occurrence of fog in selected airports located in southern Poland and its circulation factors

This article discusses the annual course and the many-year occurrence of days with fog at three selected airports and their relationship with atmospheric circulation. Fog is a relatively frequent phenomenon – it is recorded around 60 days a year. Occurrence of fog is the most threatened airport Krakow-Balice, and least Katowice-Muchowiec. Fog usually occurred in autumn, and the least in summer. The probability of fog occurring is greatest in autumn and winter. Among the advection types, the types from the southern sector play a large role in shaping the mists. The highest probability of occurrence of a day with fog occurs in the types of non-convective circulation. In these circulation conditions, radiation mists are formed, which are the dominant type of mists in southern Poland. In spring and summer, the probability of fog is the lowest. The analysis confirms that the duration of the fog represents the leading role of the landform of the airport. Short-time fogs mostly occur mainly in Balice, whereas fogs of varying duration have similar frequencies at all airports considered. The most frequent occurrences of the 24-hour fog occur also in Balice, which means that the airport is characterized by the greatest threat to the fluency of air traffic. It is responsible for the location of the aerodrome within the concave form of the land, which is characterized by a tendency to create cold air stagnation and ground temperature inversion. Through a detailed analysis of the frequency and probability of the appearance of fog, its significant relationship with the circulation was demonstrated. This relationship is so strict that on the basis of the forecasted synoptic situation, the occurrence of fog can be predicted with high probability. The possibility of forecasting the occurrence of fog, its density and the time of retention is an extremely important issue in the context of the safety of crews and passengers as well as aviation tasks.

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Mgła należy do groźnych zjawisk atmosferycznych, które utrudniają, a czasami nawet uniemożliwiają wykonanie operacji lotniczych. W pracy scharakteryzowano występowanie mgły na 3 lotniskach w południowej Polsce w latach 1981–2010 oraz jej uwarunkowania cyrkulacyjne. Podstawę badań stanowią dane dotyczące występowania dni z mgłą w Balicach, Muchowcu i Jasionce oraz kalendarz typów cyrkulacji Niedźwiedzia (2013). Najwięcej dni z mgłą wystąpiło w Balicach, a najmniej w Muchowcu, co jest uwarunkowane różnym ukształtowaniem terenu. Na wszystkich lotniskach mgła najczęściej pojawiała się jesienią, szczególnie w październiku, a najrzadziej latem z minimum częstości w lipcu. Prawdopodobieństwo wystąpienia mgły w poszczególnych porach roku było silnie zróżnicowane. Największe występuje w typach cyrkulacji bezadwekcyjnych: centrum wyżu (Ca) i klin antycyklonalny (Ka) na wszystkich lotniskach. Spośród typów adwekcyjnych dużą rolę w kształtowaniu mgieł odgrywają typy z sektora południowego. W Balicach najczęściej występują mgły o najkrótszym i najdłuższym czasie trwania, oraz te utrzymujące się minimum dobę. Na pozostałych lotniskach mgła utrzymuje się w przedziale między 6 a 12 godzin.

This article discusses the annual course and the many-year occurrence of days with fog at three selected airports and their relationship with atmospheric circulation. Fog is a relatively frequent phenomenon – it is recorded around 60 days a year. Occurrence of fog is the most threatened airport Krakow-Balice, and least Katowice-Muchowiec. Fog usually occurred in autumn, and the least in summer. The probability of fog occurring is greatest in autumn and winter. Among the advection types, the types from the southern sector play a large role in shaping the mists. The highest probability of occurrence of a day with fog occurs in the types of non-convective circulation. In these circulation conditions, radiation mists are formed, which are the dominant type of mists in southern Poland. In spring and summer, the probability of fog is the lowest. The analysis confirms that the duration of the fog represents the leading role of the landform of the airport. Short-time fogs mostly occur mainly in Balice, whereas fogs of varying duration have similar frequencies at all airports considered. The most frequent occurrences of the 24-hour fog occur also in Balice, which means that the airport is characterized by the greatest threat to the fluency of air traffic. It is responsible for the location of the aerodrome within the concave form of the land, which is characterized by a tendency to create cold air stagnation and ground temperature inversion. Through a detailed analysis of the frequency and probability of the appearance of fog, its significant relationship with the circulation was demonstrated. This relationship is so strict that on the basis of the forecasted synoptic situation, the occurrence of fog can be predicted with high probability. The possibility of forecasting the occurrence of fog, its density and the time of retention is an extremely important issue in the context of the safety of crews and passengers as well as aviation tasks.