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1

Zlodzenie Hornsundu i wód przyległych (Spitsbergen) w sezonie zimowym 2011-2012

Kruszewski G.

Problemy Klimatologii Polarnej

|

2013

|

Nr 23

169--179

PL

W pracy przedstawiono zróżnicowanie warunków meteorologicznych jakie występuje latem w rejonie Bellsundu. Analizą objęto okres od 23 czerwca do 1 września 2011 roku. Długość serii pomiarowej wynika z terminu rozpoczęcia i zakończenia Wyprawy UMCS na Spitsbergen. W pracy przeanalizowano zmienność temperatury powietrza oraz kierunku i prędkości wiatru na stacjach Calypsobyen i Akseloya. W badanym czasie na stacji Akseloya dominuje wiatr NE, a subdominuje wiatr z SW, natomiast na stacji Calypsobyen odpowiednio wiatry z ENE i NW. Na obu stacjach średnie prędkości wiatru są zbliżone. Przy wszystkich kierunkach wiatru, poza sektorem SW, temperatura powietrza na stacji Akseloya jest wyższa niż na Calypsobyen. Największe różnice temperatury występują przy wiatrach z ESE (4,3 deg). Występowanie wyraźnego ocieplenia na stacji Akseloya przy wiatrach z sektora E – SSE wiązać należy ze zjawiskami fenowymi.

EN

The paper presents a variation of meteorological conditions that are observed during summer in the region of Bellsund. The analysis covered the period from 21 June to 1 September 2011. The length of the measurement series results from the date of commencement and completion of UMCS Expedition to Spitsbergen. The paper examines the variability of air temperature and wind direction and speed at the Calypsobyen and Akseloya stations. In the analyzed period, NE wind dominates at the Akseloya station and SW wind sub-dominates there whereas at the Calypsobyen station winds from ENE and NW respectively. The average wind speeds at both stations are similar. For all wind directions, outside the SW sector, the air temperature at the Akseloya station is higher than at the Calypsobyen station. The largest temperature differences occur when winds from ESE (4.3 deg) are observed. The presence of visible warming at the Akseloya station during winds from the E-SSE sector should be associated with the phenomenon of foehn winds.

2

Zlodzenie Hornsundu i wód przyległych (Spitsbergen) w sezonie zimowym 2010-2011

Kruszewski G.

Problemy Klimatologii Polarnej

|

2012

|

nr 22

69-82

PL

Sezon lodowy 2010/2011 zaczął się w połowie października. Pierwsze postacie autochtonicz-nego lodu morskiego zaobserwowano w strefie brzegowej Isbjornhamny 15.10. po spadku dobowej temperatury powietrza poniżej poziomu temperatury zamarzania wody morskiej. Zbliżone do średnich wieloletnich wartości temperatury powietrza okresu listopad – styczeń sprzyjały tworzeniu się lodu w strefie brzegowej Hornsundu. Lód morski o zwartości do 4/10 pojawił się w Hornsundzie w końcu października i utrzymywał w listopadzie. Prze-bieg warunków lodowych w rejonie południowego Spitsbergenu – zbliżony do normalnego z wielolecia – umoż-liwiał napływ lodu do fiordu z zewnątrz od połowy grudnia. W tym też okresie w wewnętrznych partiach fiordu zaczął się formować lód stały brzegowy, którego pokrywa w sposób ciągły występowała w N części Brepollen do końca drugiej dekady lipca 2011 (około 7 miesięcy). W okresie maksymalnego rozwoju (druga dekada lutego) lód stały lub całkowicie zwarty pokrywał około 2/3 powierzchni fiordu.

EN

This paper presents the ice conditions in the Hornsund Fjord (Svalbard) during expedition season 2010/2011. Sea ice season started in the mid of October, after clear air temperature drop (Fig. 2). Since this time forms of locally formed ice were present, mainly in coastal zone. To the end of November concentration of ice did not exceed 4/10 (very open drift ice). Close to mean thermal conditions in Hornsund area during winter months (Fig.1, Tab. 1) were favourable for ice development in this region. Theoretical sea ice thickness at the end of the Year 2010 could reach about 50 cm, and close to 1 m at the end of ice season. Close and very close pack ice (7-10/10) drifting outside the fjord were present since December (Fig. 7). Easternmost inner part of the Hornsund was covered by fast (consolidated) ice since mid of December to the mid of July 2011. During its maximum development in February fast ice covered over 70% of Hornsund area. Close and very close pack ice were present at Hornsund waters in January, February, three weeks of March, second half of April and first week of May – all together over three and half months. Periods of time with smaller ice concentration were connected with strong easterly air circulation. In May and June ice concentration in SW Svalbard area decrease significantly. Last two episodes the very close ice pack flowed into the Hornsund took place in first days and in second half of July 2011 (Fig. 8).

3

Zlodzenie Hornsundu (Spitsbergen) w sezonie zimowym 2009-2010 (SW Spitsbergen)

Kruszewski G.

Problemy Klimatologii Polarnej

|

2011

|

nr 21

229-239

PL

Sezon lodowy 2009/2010 zaczął się pod koniec października. Pierwsze postacie autochtonicznego lodu morskiego zaobserwowano w strefie brzegowej Isbjornhamny dopiero 26 października. Spadki dobowej temperatury powietrza poniżej zera sporadycznie notowano od połowy września, jednak dopiero w końcu października obniżyła się ona do poziomu temperatury zamarzania wody morskiej. Wyraźnie wyższe od średnich wieloletnich wartości temperatury powietrza okresu październik - luty nie sprzyjały tworzeniu się lodu. Wyjątkowo łagodne warunki lodowe w rejonie południowego Spitsbergenu uniemożliwiały napływ lodu z zewnątrz aż do początków stycznia 2010. Lód morski o większej zwartości pojawił się w Hornsundzie w zasadzie dopiero po wyraźnym spadku temperatury w marcu. Dochodziło wtedy do całkowitego pokrycia fiordu lodem, włącznie z tworzeniem się w zatokach wewnętrznych lodu stałego. Pokrywa lodu stałego utrzymywała się we wschodniej części fiordu, w fazie maksymalnego rozwoju (od połowy marca do połowy kwietnia) pokrywając od połowy do blisko całej jego powierzchni. W skrajnie wschodniej partii fiordu pod Brepollen przetrwała do końca czerwca.

EN

This article presents the sea ice development in the waters of Hornsund Fjord during winter season 2009/2010. Due to long lasting (November-February) high air temperatures (Fig. 1-2) during autumn 2009 mainly brash glacier ice, growlers and bergy bits were present in Hornsund, especially along the coast. Since end of October forms of new ice were observed in coastal zone of Isbjornhamna. In beginning of January first allochtonic drifting ice entered western part of the fjord. First in situ formed pancake ice was observed in coastal zone in February (Fig. 4). During this month young coastal ice was formed in inner bays of the fjord. Significant decrease in air temperature observed in March was connected with ice development (Fig. 5) on whole fjord area. In eastern part the 'autochtonic' fast ice was formed, in western consolidation of drifting ice occurred. The whole area of Hornsund was covered with fast ice for about two weeks. In eastern part of the fjord (Brepollen, Burgerbukta, Samarinvagen) fast ice existed even in June, with maximum thickness 70-80 cm. Last forms of fast ice was destroyed in first days of July in NE part of Brepollen. In April and May close pack ice drifting outside the Hornsund entered few times the central parts of the fjord, but because of mild temperature conditions consolidation did not start. Usually concentration of ice in central part of the fjord was smaller than outside and do not exceed 4-6/10 (open drift), because of prevailing easterly winds, blowing the ice outside. Such a situation existed since end of March for next six weeks. The last short episode the strips of allochtonic ice entered central part of the fjord took place in beginning of May (Fig. 7).

4

Zlodzenie Hornsundu (Spitsbergen) w sezonie zimowym 2008/2009

Kruszewski G.

Problemy Klimatologii Polarnej

|

2010

|

nr 20

187-196

PL

Sezon lodowy 2008/2009 zaczął się w trzeciej dekadzie października, przy czym spadki temperatury powietrza poniżej zera notowano od końca września. Na wodach fiordu w okresie lipiec – wrzesień odnotowywano jedynie postacie lodu lodowcowego. Dopiero spadki temperatury w listopadzie umożliwiły two-rzenie się lodu autochtonicznego w strefie brzegowej. W tym samym czasie do fiordu zaczął okresowo napływać także lód dryfujący z Prądem Sorkapskim. Pokrycie fiordu lodem o dużej zwartości wystąpiło w kilku epizodach, przerywanych kilkudniowymi aktami przynajmniej częściowego odpływania lodu z Hornsundu. Zwarty i bardzo zwarty lód występowała na praktycznie całej powierzchni fiordu w drugiej dekadzie grudnia, pierwszej i drugiej stycznia, lutym, marcu, pierwszej połowie kwietnia i przez kilka dni w maju. Stała pokrywa lodowa utworzyła się poza Isbjornhamną jedynie w skrajnie wschodniej części fiordu, gdzie pod Brepollen przetrwała do pierwszych dni lipca.

EN

This paper presents the sea ice development in the waters of Hornsund Fjord during winter season 2008/2009. In autumn 2008 only brash glacier ice, growlers and bergy bits were present in Hornsund, especially along the coast. Sea ice season started at end of October. Since this time forms of new ice were formed in coastal zone of Isbjornhamna. Because of mild thermal conditions in November and December (Fig. 2, 3) the maximum theoretical ice thickness in inner parts of the fjord could reach 43 cm at the end of the year 2008 (Table 1). In January young coastal ice was formed in Isbjornhamna. Consolidation of close pack ice coming from outside the Hornsund was interrupted few times by increase in air temperature and strong easterly winds, blowing the ice outside again. In the inner bays consolidation of pack ice started probably at end of February. Eastern part of the Hornsund was covered by fast ice since mid of March to the end of June 2009 (Brepollen, Samarinvagen). For over 16 weeks close and very close young pack ice drifted in the Hornsund waters. At the end of April ice concentration in fjord and outside decrease significantly and part of fast ice was broken and removed too. Last episode the Hornsund was covered by very close pack ice drifting from outside took place from 15th till 25th May.

5

Prędkość wiatru w rejonie Svalbardu w świetle zmian warunków cyrkulacyjnych i środowiskowych

Kruszewski G.

Problemy Klimatologii Polarnej

|

2010

|

nr 20

31-44

PL

Praca charakteryzuje związki prędkości wiatru w dwunastu punktach gridowych z rejonu Svalbardu z ciśnieniem atmosferycznym, wybranymi wskaźnikami cyrkulacyjnymi i temperaturą powierzchni morza w okresie 1950-2009. Związki synchroniczne średniej rocznej i sezonowych prędkości wiatru z ciśnieniem atmosferycznym w tych samych punktach (korelacje ujemne) są zmienne w przestrzeni (silniejsze na północy) i niestabilne w czasie (słabsze w ostatnich 30. latach). Podobnie istotne korelacje prędkości wiatru ze wskaźnikiem cyrkulacji „C” Niedźwiedzia dla Spitsbergenu najliczniej występują zimą i wykazują „przesuwanie się” w czasie z północy na południe badanego obszaru. W ostatnich 30. latach odnotowano także bardzo silne związki zimowej wartości wskaźnika „S” z prędkością wiatru – najwyraźniejsze w NE części Svalbardu. W tym samym rejonie najsilniej zaznaczają się także związki rocznej prędkości wiatru z temperaturą morza.

EN

This paper deals with correlations between surface wind speed in Svalbard area and chosen environmental factors (atmospheric pressure, circulation indices, sea surface temperature). Gridded surface data from NCEP Reanalysis Derived data provided by the NOAA/OAR/ESRL PSD, Boulder Colorado from their Web site at http://www.cdc.noaa.gov/ (wind speed and air pressure), SST from NOAA NCDC ERSST v.2, AO and Nied.wied. (2006) circulation indices were used to statistical analysis over the period 1950-2009. Mean values and linear trend coefficients of wind speed in chosen grid points are in Table 1. The highest trend values are present in northern part of Svalbard in last 30 years. Linear correlation coefficients between wind speed and SLP in same grid points are strongest in northern part too, but correlations are not stable in time (Table 2, 3 and 4). Correlations between wind speed and AO index (monthly values) are week and in most cases statistically insignificant. Significant correlations are frequent between wind speed and C and S indices for winter and annual values (Table 5 and 6). Wind speed during winter in latitudes 80 and 82.5°N in last 29-year period show strong positive correlation with frequency of southern circulation S, which explains from 26 to 60% changeability of wind speed in years 1980-2009. Some correlations between wind speed and SST from grids 2°[fi] x 2°[lambda], situated in same area were found too. The highest coefficients of annual values were found in north of investigated area (wind speed in [82,5; 20] and SST in area between 81 to 83°N, and 19 to 21°E, r = +0,64) . see Fig. 2. In last 30 years significant correlations of this kind were found in NE area of interest (Fig. 3). This is probably connected with changes of the ice edge positions during last years (retreat of sea ice) in the region situated N and NE from Svalbard (Rodrigues 2009).

6

Zmiany prędkości wiatru w rejonie Svalbardu w latach 1948-2008

Kruszewski G.

Problemy Klimatologii Polarnej

|

2009

|

nr 19

159-168

PL

Praca charakteryzuje prędkości wiatru w oparciu o dane pochodzące z reanaliz NCEP/NCAR. Zmiany prędkości prześledzono w dwunastu punktach gridowych z rejonu Svalbardu. W przebiegu rocznym stwierdzono większe prędkości w miesiącach zimowych i mniejsze latem, przy czym amplituda tych zmian jest ponad dwukrotnie większa w południowej części rozpatrywanego obszaru. W przebiegach wieloletnich (1948-2008) obserwuje się istotny statystycznie wzrost rocznej prędkości wiatru w ośmiu gridach. W ostatnich trzy-dziestu latach wzrost ten przybierał na sile. Największe zmiany odnotowano w rejonie na północ od Svalbardu.

EN

The aim of this work was to analyse the surface wind speed changeability in twelve grids points situated in the vicinity of Svalbard (Fig. 1) Gridded surface data from NCEP Reanalysis Derived data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA from their Web site at http://www. cdc.noaa.gov/ were used for statistical analysis over the period 1948–2008. The highest annual wind speed values (8.0 mźs–1) were noted in the south of area (75°N), the lowest in situated over land grid [80, 20] and in the northern part of area at 82.5°N (5.9-6.0 mźs–1). During the year maximum wind speed were noted in winter months, minimum in June or July in all grid points. The differences between winter and summer values are over two times higher at 75°N than in north (82.5°N) – see Tab. 1., Fig. 2. Maximum difference (3.9 mźs–1) was noted in [75, 10], minimum (1.6 mźs–1) in [82.5, 30] grid point. Differences in wind speed between selected grid points are bigger during winter and smaller in summer. Statistically significant positive trends in annual wind speed values were found in years 1948-2008 in whole area, except at 77.5°N and [80, 20] grid point.. The trend value is the greatest in [82.5, 10] grid (+0.017 mźs–1 per year) – see Tab. 3. At latitudes 75 and 80°N values of linear trend coefficients are lower (from +0.006 to +0.01 mźs–1 per year). In shorter 30-year periods continuous significant increase in wind speed is observed at 82.5°N from 60. to the present. The highest positive trend value was noted in [82.5, 10] grid over the 1978-2008 period (+0.032 mźs–1 per year). During the last 30 years significant positive trends in wind speed are present at latitude 80°N and in grid points [77.5, 20]; [77.5, 30].

7

Zmiany prędkości wiatru przywodnego nad Bałtykiem w świetle danych z reanalizy NCEP/NCAR (1951-2005)

Kruszewski G.

Przegląd Geofizyczny

|

2008

|

Z. 1

27-41

PL

W pracy przeanalizowano zmiany prędkości wiatru przywodnego w sześciu wybranych punktach Morza Bałtyckiego. Największe prędkości roczne notowane są w obszarze Bałtyku Centralnego (według podziału WMO). W rejonach Bałtyku Południowego i Południowo-Wschodniego stwierdzono statystycznie istotne dodatnie trendy rocznej prędkości wiatru w analizowanym 55-leciu. Na Bałtyku Południowym wartość trendu jest największa (+0,012 m×s-1×rok-1). Maksima rocznych prędkości wiatru nad większością analizowanego obszaru odnotowano w połowie lat 90. ubiegłego wieku. Występowanie minimów wykazuje znaczne zróżnicowanie regionalne, jednak w ostatnich latach zaznacza się wyraźna tendencja spadkowa prędkości wiatru - najsilniejsza w rejonach Skagerraku i Bałtyku Południowego.

EN

The aim of this work was to analyse the surface wind speed changeability in six selected grid points over the Baltic Sea. The highest annual wind speed values were noted in the Central Baltic (according to WMO forecast areas). In the Southern and South-Eastern Baltic areas statistically significant positive trends in annual wind speed were found in the analysed 55-year period. In the Southern Baltic the trend in annual wind speed is greatest (+0,012 m×s-1 per year). The maximum values of the annual wind speed over the Baltic were noted in mid 90-ties of the 20th century. The minimum values show great regional diversity but during the last years the well marked negative tendency in annual wind speed occured, especially strong in Skagerrak and Southern Baltic areas.

8

Zmiany składowej strefowej prędkości wiatru (U-wind) na wschód od Svalbardu (1981-2005)

Kruszewski G.

Problemy Klimatologii Polarnej

|

2007

|

nr 17

77-85

PL

Praca charakteryzuje składową strefową prędkości wiatru w trzech gridach usytuowanych po wschodniej stronie Svalbardu oraz jej związki z temperaturą powietrza na stacjach zachodniego wybrzeża Spits-bergenu. W rejonie położonym na wschód od archipelagu obserwuje się dominację cyrkulacji wschodniej, której natężenie wyraźnie wzrasta przy przemieszczaniu się na południe. W przebiegu rocznym stwierdzono nasilanie się cyrkulacji wschodniej w miesiącach zimowych i osłabianie latem, przy czym zmienność wartości U-wind w mie-siącach chłodnej pory roku jest największa. Przewaga cyrkulacji zachodniej zaznacza się latem przez okres od jednego (na 75°N) do pięciu miesięcy (na 80°N), a jej natężenie rośnie wraz z szerokością geograficzną.

EN

The study presents variability of zonal wind speed (U-wind) in three grids 2.5x2.5° situated in the vicinity of the eastern coast of Svalbard in period 1981–2005. Gridded surface data from NCEP Reanalysis Derived data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA from their Web site at http://www.cdc.noaa.gov/ were used for statistical analysis. In analysed area negative values of U-wind are typical. Annual average eastern air-flow is much stronger in the south (–1.54 m/s in grid [75, 30]) than in north (–0.31 m/s in grid [80, 30]) – see fig. 1 and 2. The biggest interannual changeability of U-wind values is also observed in lower latitudes. Significant decreasing trends were found in annual U-wind values in grid points [80, 30] (–0.05 m/s by year) and [77.5, 30] (–0.04 m/s by year). During the year eastern air-flow reach the maximum in winter months. In summer time easterly circulation is weaker. Positive U-wind values (western air-flow) prevails in July (grid [75, 30]); June, July and August (grid [77.5, 30]) and from May to September in grid [80, 30]. Intensity of western air-flow increase with latitude too. The biggest changeability in monthly U-wind values in all grid points was observed in February. Decreasing trends in monthly U-wind values were found in [80, 30] grid in February (–0.13 m/s by year) and in [77.5, 30] grid in March and May (–0.11 and –0.08 m/s by year). Correlations between U-wind and zonal westerly circulation index W values for Spitsbergen area (given by Niedźwiedź, 2006) are strong for all grids and seasons, but the strongest were noted in grid [75, 30] – linear correlation coefficient from r = +0.75 (winter) to r = +0.87 (summer) – see fig. 5. Some relations between U-wind and monthly air temperature in Svalbard-Lufthavn and Ny Alesund were noticed too (fig. 6). The strongest negative correlations were found in July, May and April.

9

Zmiany składowej strefowej prędkości wiatru (U-wind) w rejonie Spitsbergenu Zachodniego (1981-2005)

Kruszewski G.

Problemy Klimatologii Polarnej

|

2006

|

nr 16

107-114

PL

Praca charakteryzuje składową strefową prędkości wiatru (oznaczenie U-wind) w trzech gridach położonych na zachód od Spitsbergenu Zachodniego. W rejonie tym, przy ogólnej dominacji cyrkulacji wschodniej, dwukrotnie większe jej natężenie obserwujemy w części południowej. Tam też U-wind charakteryzuje się największą zmiennością roczną. Analiza przebiegów miesięcznych także wykazuje większą stabilność wartości U-wind na północy. Cyrkulacja wschodnia wyraźnie nasila się w miesiącach zimowych; zachodnia przeważa latem, a jej natężenie i okres dominacji rosną wraz z szerokością geograficzną.

EN

The study presents variability of zonal wind speed (U-wind) in three grids 2.5x2.5° situated in the vicinity of the western coast of Spitsbergen. Gridded surface data from NCEP Reanalysis Derived data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA from their Web site at http://www.cdc.noaa.gov/ were used for statistical analysis. In Spitsbergen area negative values of U-wind are typical but the eastern air-flow is two times stronger in the south (-1.58 m/s in grid [75, 10]) than in the north (-0.78 m/s in grid [80, 10]) - see fig. 2. The biggest changeability in annual values of U-wind is also observed in the south. The maximum of the eastern air-flow can be observed in winter months, the minimum in summer, when positive values of U-wind occur. Westerly circulation prevails in June (grid [75, 10]); June and July [77.5, 10] and from May to September in the north [80, 10]. Significant decreasing (-0.05 m/s by year) trend in annual U-wind values was found in the north. Decreasing trends were observed in monthly U-wind values in February, March and May in [80, 10] and in March and May in [77.5, 10] grids. The only significant increasing trend (+0.1 m/s by year) was noted in September in the [75, 10] grid. Correlations between U-wind and zonal westerly circulation index W values for Spitsbergen area (given by Niedźwiedź 1997) are strong for all grids and seasons, but the strongest was noted in summer (r = +0.81) in grid [75, 10]. Some relations between U-wind and monthly air temperature in Svalbard-Lufthavn and Ny Alesund were noticed too. The strongest negative correlations were found in July, April and August.

10

Wpływ zmian temperatury wód w głównym nurcie Prądu Zachodniospitsbergeńskiego na temperaturę powietrza na Spitsbergenie Zachodnim (1982-2002)

Kruszewski G.

Problemy Klimatologii Polarnej

|

2005

|

nr 15

53-63

PL

Praca omawia związki temperatury powietrza na trzech stacjach Spitsbergenu Zachodniego z temperaturą wody powierzchniowej na akwenach położonych po zachodniej stronie wyspy - w nurcie Prądu Zachodniospitsbergeńskiego. Przeprowadzona analiza korelacji ciągów temperatury wody i powietrza wykazała istnienie między nimi istotnych statystycznie związków. Najwyższe współczynniki korelacji (osiągające nawet wartość +0.80) występują w okresie jesieni - między wartościami temperatury powietrza i wody z tego samego miesiąca. Związki pomiędzy roczną temperaturą powietrza a miesięcznymi wartościami temperatury wody są tylko nieznacznie słabsze. W niektórych przypadkach zmiany miesięcznej temperatury powierzchni wody objaśniają ponad 40% zmienności rocznej temperatury powietrza na Spitsbergenie.

EN

This work deals with correlations between SST in the West Spitsbergen Current and air temperature at Spitsbergen (Hornsund, Svalbard-Lufthavn and Ny Alesund). The strongest correlations SST with air temperature have been found in the southern part of the West Spitsbergen Current. In grid [76, 14] synchronic correlations (SST & air temperature in the same month) are strongest and most frequent, occurring in fall and winter months at all three stations (table 1). Correlations in summer months are strong only with closest station at Hornsund (r = 0.67 in July), and decrease with distance to the station. Synchronic correlations between monthly air temperature and SST in next two grids are less frequent and weaker. In [77, 10] grid statistically significant synchronic correlations are limited to fall and winter months and in [78, 06] grid occur in November only (see table 2 & 3). Correlations between monthly SST and annual air temperature are strongest for October, November and December in [76, 14] grid, and coefficients of correlation are very close for all three stations and months (0.62 < r < 0.70) - see Fig. 5. Interesting correlation occur between SST in April and May and annual air temperature values at Spitsbergen, especially strong at Ny Alesund and SST in May in [77, 10] grid (r = 0.66). The changeability of SST in this area in May explains from 31% (Hornsund) to 41% (Ny Alesund) of changeability in annual air temperature at Spitsbergen.

11

Zmienność temperatury powierzchni morza w rejonie Spitsbergenu (1982-2002) jako przejaw współcześnie zachodzących zmian klimatycznych

Kruszewski G.

Problemy Klimatologii Polarnej

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2004

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nr 14

79-86

EN

This work has analysed changeability in water surface temperature in sea areas in the direct vicinity of West Spitsbergen. (Fig. 1). The analysis made use of SST (Sea Surface Temperature) from Reynolds?s data, covering mean monthly values of grids 1 x 1° from the period 1982-2002 (21 years). The changes in SST have been examined both monthly and yearly in 48 grids originating from the region 76-80°N, 006-020°E. A noticeable increase in water temperature was noted in the entire analysed area. The highest positive annual trends in water temperature were noted in the region 77-78°N, 006-007°E located west of Spitsbergen. In this area the mean yearly trends in SST values exceed +0.11°C/year and are highly statistically relevant (p<0.001). The values of trend noted in the areas in the direct vicinity of SW coast of Spitsbergen are +0.07°C to +0.08°C/year (at the latitudes 76-78°N). Farther north the values of the trend are remarkably lower, yet they are still highly statistically relevant. At 80°N the SST trend ranges from +0.006°C to +0.013°C and grows when moving west. At 79°N the observed trend of mean yearly value of SST is within the range from +0.04°C (010°E) to +0.07°C/year (006°E). This indicates that the mean yearly temperature of water in the region west of Spitsbergen has increased by more than 2.5°C over the period of the last 21 years and in coastal waters SW of Spitsbergen by about 1.5°C to 1.7°C. The lowest increase in SST was noted in waters at 80°N, where it did not exceed 0.3°C within 21 years. The increase in water temperature is distributed unevenly in time - since 1995 the rate of the increase has been rapidly growing (see Fig. 2). The changes in yearly SST values, as the analysis indicated, are influenced by the changes in temperature noted mainly in the period from September to February. This proves that the heat sources carried by the West Spitsbergen Current are increasing and that the summer warming of waters is becoming more and more significant. Interannual changeability in SST in the remaining months proves to be relatively low, in extreme cases being zero (water completely frozen). It can be observed especially at 80°N. The yearly changeability in values of SST in waters around SE coasts of Spitsbergen (Storfjorden) is mainly influenced by the temperature of waters in autumn (August ? October), which means that the influence of the summer warming of waters on the yearly SST value in this area has increased.

12

Wpływ zmian temperatury powierzchni oceanu na Morzu Norweskim na temperaturę powietrza na Svalbardzie i Jan Mayen (1982-2002)

Kruszewski G., Marsz A. A., Zblewski S.

Problemy Klimatologii Polarnej

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2003

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nr 13

59-78

EN

This work deals with correlations between SST in the Norwegian Sea and air temperature at selected stations located in the Atlantic sector of Arctic (Bjornoya, Hornsund, Svalbard-Lufthavn, Ny Alesund and Jan Mayen). The southern and central parts of the Norwegian Sea show the strongest correlation with the air temperature at the above mentioned stations, whereas the northern parts of this sea show weaker correlation. Apart from synchronic correlations (occurring in the same months) asynchronic correlations have been found. The latter are generally much stronger than the synchronic ones. The predominant influence on the changes in air temperature at the stations have the winter SST (JFMA) in the central part of the Norwegian Sea (grid 2° x 2°, 67°N, 010°E). These winter SST show quite strong correlations with monthly air temperature at Bjornoya, Hornsund, Svalbard-Lufthavn and Jan Mayen in July, August and September. At Ny Alesund station the period with statistically significant correlation between the air temperature and the winter SST is limited to September. The strongest correlation can be observed in August (see Table 4). The observed correlations result from modification in atmospheric circulation, caused by increased heat volume in the Norwegian Sea. Such modification is reflected in the increased frequency of occurrence of meridional atmospheric circulation, which is accompanied by the increase in the frequency of air advection from the S to this sector of Arctica. Some correlations which show more significant time shift have also been observed (see Table 5). Winter SST indicate positive correlations with air temperature observed at Bjornoya and Horn-sund in August and September the following year and at Svalbard-Lufthavn in September. At Ny Alesund station the coefficients of correlation with the air temperature in the following year are increased but they do not reach the statistically significant level. Another period with statistically significant correlations is November and December the following year; significant correlations with winter SST occur at Bjornoya (r = 0.71) and all stations located on Spitsbergen (r = 0.57). The correlations of SST with air temperature observed at Jan Mayen the following year are different, i.e. the presence of strong correlations is limited to summer season - July, August and September (r ~ 0.6). The correlations with winter SST occurring in November and December the following year is connected with warm masses carried to this region together with waters with the West Spitsbergen Current. Correlations between SST and air temperature present in summer and at the end of summer the following year may probably be influenced by the modification of atmospheric circulation. The only significant correlation with summer (July and August) SST indicates the temperature of February the following year at stations located on Spitsbergen and Jan Mayen. These correlations are negative (r ~ -0.55 - -0.50). The reason for occurrence of such correlations is not clear. The changeability of winter SST in the central part of the Norwegian Sea explains from 20% (Hornsund) to 32% (Bjornoya) of changeability in annual air temperature at the above mentioned stations in the same year and from 34% (Jan Mayen) to 41% (Hornsund) of changeability in annual air temperature in the following year. The increased level of explanation of changeability in air temperature the following year influenced by winter SST is connected with the delayed flowing of the Atlantic waters to high latitudes carried with the Norwegian Current and the West Spitsbergen Current.

13

Zlodzenie Zatoki Admiralicji a temperatura wody w energoaktywnej strefie Morza Bellingshausena (1982-1997)

Kruszewski G.

Problemy Klimatologii Polarnej

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2001

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nr 11

105-112

EN

Correlations, especially those on a regional scale, between the sea ice cover formation and the air and sea surface temperatures have been pointed out by a number of authors. Region that is clearly marked by such correlation is located NW of the Antarctic Peninsula (among others Weatherly and others, King 1994, Styszyńska 1997, 2000). The intensity of ice formation in the relatively small Admiralty Bay noted in a given winter season indicates strong correlation with the winter sea ice cover extent in a regional scale (Kruszew-ski 1999, 2000). This ice cover is influenced (among others) by the sea surface temperature. The possible nature of the correlation between the sea surface temperature (SST) at the meridian of 080°W and the changes in air temperature in the region of the Southern Shetlands as described by Styszyńska suggested the presence of similar correlations with the intensity of ice formation in that region, so in this way also in the Admiralty Bay. With the help of Spearmann correlation coefficient a number of statistically significant relations have been found between the course of SST in the region of 086-062°W and the intensity of ice formation in the Admiralty Bay are presented in a categorised way. These relations are both synchronic and asynchronic. The synchronic correlation is observed mainly between SST in winter months and the ice cover category in the same year (the increase in SST is followed by the decrease in ice cover category).These correlations are most significant in the region 62-66°S (July - September). They also occur farther north 56-58°S but this time in the eastern part of the said region (March-July) and they are also observed in 60-64° (but in January and February). The asynchronic correlations have been observed between SST in October and ice cover category of the Admiralty Bay in the following year(8-11month slater). These correlations are most significantly marked in 56-64°S (the northern part of the Bellingshausen Sea and in the Circumpolar Current region) especially in 60°S 080°W (r = -0.677, p < 0.01) and their character is similar to those of the previously mentioned synchronic correlations.

14

Zlodzenie Zatoki Admiralicji w latach 1977-1996 (Wyspa Króla Jerzego, Szetlandy Południowe)

Kruszewski G.

Problemy Klimatologii Polarnej

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1999

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nr 9

173--191

EN

Ice conditions are one of the most difficult to analyse, because of number of factors having influence on it. The analysed historical data from the past 20 years were difficult to verify, because of the lack of the systematic observations ice conditions. The number and scale of factors, having influence on ice cover being built up and disintegrated are too large to analyse them one by one. In such case it is more easy to create “ice conditions categories, which will characterise main conditions of ice cover in different years (seasons). The presented ice categories in on easy way describe features of ice conditions intensity in the waters the Admiralty Bay waters. Using them it is easy to show the changeability phenomenon, difficult to explain in a different way, because of too large number of possible factors - different in different seasons – having influence on ice formation and disintegration. Ice conditions categories play the role of the 'local factor' in ice phenomena variations in the analysed area. Ice condition categories as shown in Table 1 are strong and significant correlated on level r = 0.705 (Spearman correlation) with values of AlGl given by Hewitt (1997), which describe ice extent during a year on the area 104 larger than the Admiralty Bay.