- Tytuł:
-
Wieloletnia zmienność występowania ekstremów opadowych w Hornsundzie (Spitsbergen) i ich związek z cyrkulacją atmosfery
Long-term variability of extreme precipitation in Hornsund (Spitsbergen) and their relation with atmospheric circulation - Autorzy:
- Łupikasza, E.
- Powiązania:
- https://bibliotekanauki.pl/articles/260784.pdf
- Data publikacji:
- 2007
- Wydawca:
- Stowarzyszenie Klimatologów Polskich
- Tematy:
-
opady ekstremalne
cyrkulacja atmosferyczna
tendencje i zmienność opadów
Hornsund
atmospheric circulation
tendencies and changes in precipitation - Opis:
-
Celem opracowania jest określenie charakterku wieloletnich zmian i zmienności ekstremów opadowych w okresie obserwacji instrumentalnych w Hornsundzie oraz zbadanie synoptycznych przyczyn ich występowania. Badania przeprowadzono na podstawie dobowych sum opadów atmosferycznych z okresu lipiec 1978 – grudzień 2006. Za ekstremalne zjawisko opadowe uznano dobową sumę opadów przekraczającą wartość progową opadu, zdefiniowaną jako 90 i 95 percentyl. Ogólne tendencje w przebiegu czasowym wskaźników opadów ekstremalnych zbadano stosując analizę trendów metodą Mann-Kendala. Związki pomiędzy ekstremal-nymi zdarzeniami opadowymi i cyrkulacją atmosferyczną zbadano poprzez obliczenie częstości opadów ekstre-malnych oraz prawdopodobieństwa warunkowego ich wystąpienia w poszczególnych typach cyrkulacji według T. Niedźwiedzia.
Exploration of the long-term variability of precipitation extremes and its connections with atmo-spheric circulation is the main goal of this study. Daily precipitation total for the period July 1979 – December 2006 measured at Hornsund station located at West coast of Spitsbergen as well as calendar of circulation types for Spitsbergen (Niedźwiedź 2006) were used. Extreme precipitation was defined as days with precipitation above the 90th and 95th percentile calculated based on days with precipitation >0.1mm and >1.0 mm in the period 1979–2005. Several indices of precipitation extremes, describing its frequency, amount and share in the overall total were calculated for year, accumulation period (September-May), both warm (April-September) and cold (October-March) half-years and submitted to further analysis. In order to research the general trends of extreme precipitation indices Mann-Kendal method was applied. Relation between extreme precipitation characteristics and atmospheric circu-lation were investigated by analysis of frequency of extreme precipitation and conditional probability its occurrence at each of circulation types used. The most significant trends were noted in the case of share of extreme precipitation in overall precipitation totals whereas annual as well as accumulation period values of extreme precipitation indices were characterized by the most permanent trends. No statistically significant tendencies of extreme precipitation were observed for its warm half-year values. All indices of precipitation extremes show decreasing tendency from 1979 to the middle of the eighties. Clear increasing tendencies of the number of days with extreme precipitation, extreme precipitation total as well as its share in overall precipitation totals fall on the second half of the eighties and on the nineties. Weak decreasing tendencies of the annual values of extreme precipitation indices as well as their values for accumulation period and cold half-year were observed at the end of the 20th century and at the beginning of the new century (21st). Opposite direction of the extreme precipitation trends within the period mentioned above were only noted in the cold half-year. In the long-term variability of the extreme precipitation in Hornsund two sub periods (1979-1993 and 1994-2006) different in the averages values of the extreme precipitation indices can be pointed out. Extreme precipitation is the most probable at SWc synoptic situation in the warm half year whereas in the cold half-year extreme precipitation occurs with the highest probability at southern inflow of air masses at cyclonic situation (Sc). 103 - Źródło:
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Problemy Klimatologii Polarnej; 2007, 17; 87-103
1234-0715 - Pojawia się w:
- Problemy Klimatologii Polarnej
- Dostawca treści:
- Biblioteka Nauki
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