Cyrkulacyjne uwarunkowania występowania typów pogody w Hornsundzie w latach 1991-2000

Omówiono zależności elementów meteorologicznych od cyrkulacji atmosferycznej w ujęciu klimatologii kompleksowej. Do tego celu wykorzystano dane z Polskiej Stacji Polarnej w Hornsundzie z lat 1991-2000 oraz uproszczony kalendarz typów cyrkulacji dla Spitsbergenu. Najczęściej występujące cyklonalne masy powietrza ze wschodu i południowego wschodu odpowiadały za najwyższą frekwencję dni ciepłych z silnym wiatrem i opadem. Wpływ oceanu przejawiał się znacznymi frekwencjami pogód ciepłych z wysoką wilgotnością i opadem przy cyrkulacji cyklonalnej z południa i południowego zachodu.

This paper describes influence of air masses advection on meteorological elements in Hornsund (SW Spitsbergen) from 1991 to 2000. Air temperature, wind speed, relative humidity and precipitation occurrence were considered. First three variables were classified as a system of three classes. First class consists of elements below 25% percentile (under normal), third contains values above 75% percentile (above normal). Second class contains values between first and third threshold values (normal). Precipitation was classified using two-class system which describes if it occurs or not. All statistics are presented for three periods. First for all, for year term, next for polar day (24th April to 18th September) and in the end for polar night (31st October to 11th February). Reduced classification of circulation types by Niedźwiedź (2004) was used as a circulation index. Warm days (3WFR) with strong wind (T3FR) and precipitation occurrence (TWF1) exhibited the highest frequency in cyclonic E+SE situation for whole year period. High humidity (TW3R) dominated with cyclonic circulation from S+SW. Cold weather (1WFR) with low humidity (TW1R) was characteristic for N+NE advection, both cyclonic and anticyclonic. Central high situation (Ca+Ka) and also cyclonic advection from N+NE were typical for days with weak wind (T1FR) and no precipitation (TWF0). During polar day warm days (3WFR) had the highest occurrence in cyclonic advection from E+SE and S+SW. The highest frequency of strong wind days was noted with advection from E+SE, in both kind of air masses. High humidity (TW3R) weather was formed under the influence of cyclonic oceanic air masses from S+SW. Precipitation occurrence (TWF1) was mostly connected with situation Cc+Bc but in S+SWc situation accounted for almost 100% days. Cold days (1WFR) with weak wind (T1FR), low humidity (TW1R) and without precipitation were characteristic for situation with the highest frequency during polar day (Ca+Ka). During polar night warm days (3WFR) with high humidity (TW3R) had the highest frequency in cyclonic S+SW advection. Situation E+SEc was typical for days with strong wind (T3FR) and precipitation (TWF1). There weren't any days without precipitation occurrence at S+SWc advection. Cold days (1WFR) with weak wind (T1FR), low humidity (TW1R) and without precipitation were determined with the lowest frequency by cyclonic advection from N+NE.