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Warunki topoklimatyczne w sezonach letnich w rejonie Kaffioyry (NW Spitsbergen) w latach 2005-2009

Kejna M., Przybylak R., Araźny A., Jankowska J., Maszewski R., Wyszyński P.

Problemy Klimatologii Polarnej

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2010

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nr 20

63-81

PL

W artykule przedstawiono zróżnicowanie temperatury i wilgotności względnej powietrza oraz kierunku i prędkości wiatru w rejonie Kaffioyry (NW Spitsbergen) w sezonach letnich 2005-2009. Na podstawie pomiarów w 8 punktach stwierdzono znaczne różnice topoklimatyczne uwarunkowane rodzajem podłoża, wyso-kością nad poziom morza, odległością od morza, ekspozycją oraz lokalną cyrkulacją atmosferyczną. W rejonie Kaffioyry często występują sytuacje inwersyjne, związane nie tylko ze stratyfikacją termiczno-wilgotnościową napływających mas powietrza, ale również oddziaływaniem czynników lokalnych. Zróżnicowanie topoklima-tyczne zmienia się w zależności od stopnia zachmurzenia i pory doby oraz w czasie formowania się wiatrów lokalnych (wiatry lodowcowe i fenowe).

EN

The paper presents the spatial differentiation of the meteorological conditions in the summer seasons in the Kaffiřyra in the period 2005-2009. The meteorological measurement points (4 automatic weather stations and 4 electronic devices measuring temperature and humidity, 2 m a.g.l.) were located on the Kaffiřyra Plain (KH) on the Waldemar Glacier area (ATA, LW1, LW2) and on the mountains: Kuven (KU), Grĺfjellet (GF) and Prins Heinrichfjella (PH1, PH2). The analysed five seasons had changeable weather conditions dependent on types of synoptic situations. The highest air temperatures were recorded on the coast (KH 5.8°C) and on the marginal zone of the Waldemar Glacier (ATA 5.1°C). On the glaciated area air temperature is decreasing with the altitude (LW2 2.9°C). The largest temperature lapse-rate is recorded at the transitional area between the glacier and its marginal zone. Growing altitude lowers air temperature on the mountain ridges (GF 4.0°C, PH2 3.6°C), but temperature inversions are recorded quite frequently in the region. Relative air humidity is high due to low temperature and large frequency of occurrence of maritime air masses. The highest mean relative air humidity was recorded on the coast (KH 88%) and on the firn field of the Waldemar Glacier (LW2 84%) as well as on the mountain ridges (PH2 92%). The course of the relative humidity is significantly influenced by foehn winds. Wind directions and velocity in the study area are strongly dependent on the synoptic situation and influence of local factors, mainly orography (foehn winds). Wind regime in the Waldemar Glacier significantly differs from that observed in the Kaffiřyra (here the tunnel effect is observed as a consequence of the narrow Forlandsundet, presences to the abovementioned plain), mainly due to katabatic winds occurrence.

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Zróżnicowanie opadów atmosferycznych w rejonie Kaffioyry (NW Spitsbergen) w sezonie letnim w latach 1980-2008

Przybylak R., Araźny A., Kejna M., Maszewski R., Wyszyński P.

Problemy Klimatologii Polarnej

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2009

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nr 19

189-202

PL

W opracowaniu przedstawiono zróżnicowanie warunków opadowych w rejonie Kaffioyry (NW Spitsbergen) w sezonie letnim na podstawie danych z lat 1980-2008. Zbadano wpływ cyrkulacji atmosferycznej i warunków lokalnych na opady atmosferyczne. Uzyskane wyniki porównano ze stacją Ny-Alesund.

EN

Precipitation in the Arctic, including Spitsbergen, is very important for both the biosphere and for the mass balance of glaciers. Our knowledge about its values inside Arctic islands is limited because almost all meteorological stations are located on tundra below 200 m a.s.l. Therefore any information about precipitation conditions occurring on glaciated and non-glaciated areas lying in the inner parts of Spitsbergen is very valuable. In this paper we present results of precipitation measurements carried out in north-western Spitsbergen (the Kaffioyra region and the Ny Alesund station) in selected summer seasons during the period 1980-2008. Precipitation measurements in the Kaffioyra region have been done during Toruń Polar Expeditions in three stations (base station – Kaffioyra-Heggodden (KH) and two glacier stations located in the lower part (LW1) and upper part (LW2) (see Figure 1 and Table 1). Data for the Ny Alesund (NA) station were obtained from the Norwegian Meteorological Institute. In the KH and NA stations measurements were recorded every day, while in LW1 and LW2 they were generally taken every 1-2 days. Results of precipitation conditions are presented for a common period of observations, i. e. for 21st July-31st August. The influence of atmospheric circulation on precipitation was investigated using the catalogue of circulation types constructed by Niedźwiedź (2009). In the summer season precipitation is greater at the end of the study period, than at the beginning. Year-to-year variability of summer precipitation totals is very large. For example, in KH, the highest precipitation (122.5 mm) occurred in 1997, while the lowest (12.3 mm) was in 2007 (Table 2). Also, the frequency of daily precipitation (.0.1 mm) is significantly greater in most wet summer (61.9%) than in most dry summer (28.6%) (see Table 3). Daily precipitation of .10 mm is rare in the KH station and occurred in only 4 out of the 12 summer seasons. It is well known that precipitation is greater in the inner parts of Spitsbergen than in tundra areas. Less is known, however, about the magnitudes of these differences. For the Kaffioyra region precipi-tation observations are available for 9 summer seasons (Tables 5 and 6). From these Tables and Figure 2 it is clear that precipitation on glaciers is almost always greater than in tundra. On average, summer precipitation totals are greater in LW1 and LW2 than in KH by 21.5 and 35.1 mm, respectively. The greatest differences occurred in 1980, while the lowest were in 2007, when even in LW1 precipitation was lower than in KH (Table 5, Figure 3). Lapse rates of precipitation in the Kaffioyra region are greatest between tundra and glaciated areas (oscillating between 13.2mm/100m and 18.5mm/100m between KH and LW2 and KH and LW1, respectively (Table 7)). On the other hand, this lapse rate between stations LW1 and LW2 is the lowest (only 10.7 mm/100 m). Correlation coefficients of 10-day precipitation totals between the meteorological stations in the Kaffioyra region are very high and exceed 0.9. The greatest precipitation in the Kaffioyra region occurred during the inflow of air masses from the southern sector (Table 8, Fig. 7).

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Ciśnienie atmosferyczne w Arktyce w okresie Pierwszego Międzynarodowego Roku Polarnego 1882/83

Przybylak R., Wyszyński P.

Problemy Klimatologii Polarnej

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2009

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nr 19

99-114

PL

W artykule przedstawiono szczegółową charakterystykę ciśnienia atmosferycznego w Arktyce w okresie trwania Pierwszego Międzynarodowego Roku Polarnego 1882/83, do której wykorzystano cogodzinne obserwacje z 9 stacji reprezentujących większość regionów klimatycznych w Arktyce. Analizą objęto następujące parametry ciśnienia atmosferycznego: średnie dobowe, maksymalne i minimalne wartości dobowe oraz ich ekstrema. Szczegółowo omówiono rozkłady przestrzenne, przebiegi roczne oraz zmienność międzydobową. Uzyskane wyniki porównano ze współczesnymi (1961-1990) warunkami barycznymi. Ponadto zbadano współzależności między ciśnieniem atmosferycznym a innymi elementami meteorologicznymi takimi jak temperatura powietrza i stopień zachmurzenia ogólnego nieba.

EN

The paper describes atmospheric pressure characteristics of the Arctic during the First Interna-tional Year 1882/83 based on hourly data gathered for nine stations representing almost all climatic regions of that area (Figure 1). For the analysis the following parameters have been used: mean daily atmospheric pressure (p, calculated from 24 hourly data), daily maximum (p max) and minimum (p min) pressures (selected from 24 hourly data) and extreme values (p max abs, p min abs). The main focus of the paper is directed to the spatial distribution, annual courses of pressure parameters and day-to-day variability of atmospheric pressure. The historical air pressure data were also compared with modern (1961-1990) data. Furthermore, correlation between atmospheric pressure and other meteorological elements (air temperature and cloudiness) has been examined. The spatial distribution (Table 1 and Figure 2) of atmospheric pressure over the Arctic during the First International Polar Year was similar to modern. The Siberian region and the Canadian Arctic had the highest pressure, while the Norwegian Arctic, and areas around the Baffin Bay, showed the lowest average values. The pressure fields in particular seasons reflected pressure patterns that are known today. In the annual course (Table 1 and Figure 3), the lowest monthly means of air pressure occurred during the months of February or March in the Atlantic Arctic and the region of Baffin Bay. Low pressure was also noted in January. In contrast, maxima in pressure occurred mainly in spring. A greater range of variation of air pressure was observable in wintertime than in summertime. The annual courses were different in Siberian and Pacific regions, where the minimum pressure occurred in June and August respectively, in turn maxima occurred in April and February. However, the extent of variation in pressure in the cool season in the Siberian and Pacific regions corresponded with the results obtained for other regions in the Arctic. Monthly averages of day-to-day variability (Figure 4) in atmospheric pressure across the Arctic, with the exception of the Siberian station Sagastyr, showed a maximum in the wintertime. On the other hand, the lowest variability occurred during the summer months. The atmospheric pressure in the Arctic during the First International Polar Year was, on average, lower by 0.7 hPa than today (Table 2). Positive pressure anomalies occurred during the spring, autumn and summer in the Atlantic sector, whereas in the Canadian region and Alaska negative anomalies dominated in nearly all months. However, the differences between the historical and the modern period were not significant. Pressure anomalies in 90% lies within the two standard deviations (Figure 5) from the multi-annual average of the modern period. In the Arctic in the study period, a slight negative but statistically significant correlation between atmospheric pressure and cloudiness was found (Figure 6). Generally, the increase in pressure caused a decrease in cloudiness. The relationship between atmospheric pressure and air temperature was mixed. The increase or decrease of air temperature was mainly influenced by the atmospheric circulation.