Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: sumy opadowe

Sortuj według:

Ogranicz wyniki do:

Ujemny trend rocznych sum opadowych na Stacji im. H. Arctowskiego (Wyspa Króla Jerzego, Szetlandy Pd., Antarktyka Zach.)

Marsz A. A.

Problemy Klimatologii Polarnej

1998

nr 8

63--77

The paper treats variabiliry of annual precipitation sum registred at the Arctowski Station for the 1978-1996 time period. The annual sum of precipitation show a big variability, its to possible to distinguish three periods in their course. For the period 1978-1985 mean annua1 precipitation sum amounted 560 mm (δn = 26 mm), for the next period (1986-1989) precipitation sum was characterised by a very strong variability (min = 377, max = 630 mm) mean precipitation sum amounted 472 mm,where δn = 95.4 mm. For the last, third period (1990-1996) mean precipitation sum amounted 456 mm (o n = 26.1 mm) (tab. l, fig. 1). Occurrence of strong periodicty every 6.0, 2.0, 4.50, 2.57 and 9.0 years has been found for the course of annual precipitation sum (fig. 2). Also, the spectrum analysis of a course of monthly precipitation sum in March (maximum of precipitation) and August (minimum of precipitation) has been led. Analysis showed the existence strong common periodicity (for annual and month sum: maximum and minimum) every 2.00, 3.60 and 6.00 years. Analysis of amplitudes and phases of periodicity do not explain the occurrence of so big variability of observed precipitation sum. The strong negative trend of annual precipitation sum, significant from the statistic point of view occurs here (fig. 3, formula l). Negative trends were also found in: the course of mean monthly precipitation sum for 8 from 12 monts of a year (the strongest and significant in February), in the course of number of days with measurable precipitation, in the mean annual twenty-four-hours precipitation sum. The negative trend of precipitation sum at Arctowski Station is not conformable to signalised (Ackley S., Bentley C., Foldvik A., Clarke A., King J, Priddle J. 1996.) positive trend of precipitation sum, which appears on the west coast of the Antarctic Peninsula. The examination of relation between precipitation sum at the Arctowski Station with walues of SOI shows, that the strongest relations between annual and maximum precipitation sum in a given year appears with one year delay (SOI of the previous year - precipitation of the present year), whereas in case of minimum sum the strongest relation appears with three years defay (tab. 2). The significant relation between monthly precipitation sum at the Arctowski Station and values of SOI appears in January and February (fig. 4, the strongest correlation with values of SOI are the end of winter and spring of the previous year). The negative trend of SOI correspond with the negative annual precipitation sum at the Arctowski Station. The observed environmental results, which confirms decrease of precipitation sum at the Arctowski Station has been shortly discussed (decrease of fields of permanent snow, disapperance of lakes and seasonal streams, drying of seashore terraces, hastening of ablation of glaciers ice from a surrounding glaciers, hastening of deglaciation processes).