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Tytuł:
Mean air temperatures at definite wind directions in Hornsund, Spitsbergen
Autorzy:
Wielbińska, Danuta
Skrzypczak, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/2053230.pdf
Data publikacji:
1988
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
Spitsbergen
wind direction
air temperature
Źródło:
Polish Polar Research; 1988, 9, 1; 105-119
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variations in weather on the East and West coasts of South Spitsbergen, Svalbard
Autorzy:
Maciejowski, Wojciech
Michniewski, Adam
Powiązania:
https://bibliotekanauki.pl/articles/2051847.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
Spitsbergen
air temperature
air humidity
foehn effects
Źródło:
Polish Polar Research; 2007, 2; 123-136
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in thermal indices on Herschel Island (Qikiqtaruk, Canada) between the periods 1899–1905 and 2008–2014
Autorzy:
Jarzyna, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/16648059.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Arctic
Yukon Territory
air temperature based indices
Opis:
The paper provides a comparison of minimum air temperature (TN), maximum air temperature (TX), mean air temperature (Tmean) and a few derived temperature indices for Herschel Island (Qikiqtaruk) in the Yukon Territory, Canada for the periods 1899–1905 and 2008–2014. A significant increase in the TN was noted at +4.2°C, which was a larger increase than that for both Tmean (+3.7°C) and TX (+3.5°C). Air temperature increased the most in October, November, and December. In addition, the length of the frost-free season increased by 26 days and the length of the growing season increased by 25 days from the early 20th century to the early 21st century. The increase in the TN also triggered a change in the plant hardiness zone where Herschel Island is located. However, the daily air temperature range declined over the course of the study period as well as the annual total of heating degree days and the number of exceptionally cold days. No statistically significant change in the number of freeze-thaw days was found for the studied periods.
Źródło:
Polish Polar Research; 2023, 44, 1; 21-39
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial differentiation of air temperature and humidity on western coast of Spitsbergenin 1979-1983
Autorzy:
Przybylak, Rajmund
Powiązania:
https://bibliotekanauki.pl/articles/2052764.pdf
Data publikacji:
1992
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
Spitsbergen
climate
air temperature and humidity
Źródło:
Polish Polar Research; 1992, 13, 2; 113-129
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial variation of air temperature in the Arctic in 1951-1990
Autorzy:
Przybylak, Rajmund
Powiązania:
https://bibliotekanauki.pl/articles/2052494.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
air temperature changes
spatial relations
correlation analysis
Źródło:
Polish Polar Research; 1997, 18, 1; 41-63
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Warming and drying of tundra and glacier summer climate in NW Spitsbergen from 1975 to 2014
Autorzy:
Przybylak, Rajmund
Araźny, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2046837.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
air temperature
Arctic
Kaffiøyra
precipitation
Svalbard
Waldemar Glacier
Źródło:
Polish Polar Research; 2016, 37, 2; 173-192
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Summer weather conditions in 2005 and 2016 on the western and eastern coasts of south Spitsbergen
Autorzy:
Ziaja, Wiesław
Sulikowska, Agnieszka
Wypych, Agnieszka
Mitka, Krzysztof
Maciejowski, Wojciech
Ostafin, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2042136.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
Svalbard
weather variability
air temperature
atmospheric circulation
Źródło:
Polish Polar Research; 2018, 39, 1; 127-144
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ zmian temperatury wody na Prądzie Norweskim na kształtowanie rocznej temperatury powietrza w atlantyckiej Arktyce i notowane tam ocieplenie w okresie ostatniego 20-lecia
The influence of changes in water temperature in the Norwegian Current on annual air temperature in the Atlantic part of the Arctic and its warming noted over the past 20-year period
Autorzy:
Styszyńska, A.
Powiązania:
https://bibliotekanauki.pl/articles/260694.pdf
Data publikacji:
2004
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
temperatury powietrza
temperatury wody
Arktyka
water temperature
air temperature
Arctic
Opis:
Kruszewski, Marsz and Zblewski (2003) found out that winter temperature of water in the Norwegian Current indicates quite strong, occurring with a delay, correlations with the air temperature at Spitsbergen, Bjornoya, Hopen and Jan Mayen. Strong and statistically significant correlations between the mean sea surface temperature (SST) in the period January-March in grid 2°x2° [67°N, 10°E] and the monthly temperature of July, August and September with SST are marked the same year (3-5 month delay) and with the air temperature in November and December the following year (18-20 month delay). Waters of the Norwegian Current transport warm, of higher salinity Atlantic waters. Winter SST of the Atlantic Ocean characterizes the heat resources in the deeper layers of waters. SST in grid [67,10] in an indirect way characterizes heat resources carried with the Atlantic waters into the Norwegian Sea and farther to the Arctic together with the West Spitsbergen and Nordcap currents. The aim of this work is to describe the influence caused by changes in heat resources transported to the Arctic with the Norwegian Current on the annual temperature of air in the region of Hopen, Spitsbergen and Jan Mayen. The examined period covers the years of 1982?2002 and is marked by great warming in this area. The analysis of spatial distribution of correlation coefficients justifies Kruszewski and others (2003) hypothesis of mechanism causing the delayed influence of changes in water heat resources on the air temperature in this region The observed positive correlations between winter SST in [67,10] grid and air temperature in July, August and September result in the influence of changing water heat resources on atmospheric circulation noted in these months. Positive correlations in November and December in the following year result from the ?onflow? to the Arctic of warmer and of high salinity Atlantic waters. They have influence on the ice formation on the Greenland and Barents seas thus causing that influence of changing heat resources carried with waters on air temperature is much stronger. The analysis of regression made it possible to establish the correlation between annual air temperature at a given station (Ts) and winter water temperature (Tw) in [67,10] grid. Annual temperature in a year k is a function of two variables: Tw of the same year as the temperature Ts (Tw(k)) and Tw from the preceding year (Tw(k-1)): Ts(k) = A + b . Tw(k) + c . Tw(k-1) Table 3 contains the values of constant term and regression coefficients as well as statistical characteristics of formulas for the analysed stations. Both variables Tw from the year k and the year k-1 explain about 40% of the changeability in mean annual air temperature of the observed 20-year period at the analysed stations. This means that only one element, i.e. heat resource in the waters of the Norwegian Current, defined with the value Tw, determines more than 1/3 of the whole annual changeability in air temperature in the region located from Jan Mayen up to Hopen and from Tromso up to Ny Alesund. The station for which maximum explanation may be applied (47.7%) is Hopen, the station where the positive trend in annual temperature is the highest (+0.090°C/year). The values of regression coefficients b and c prove that the inertial factor connected with advection of the Atlantic waters has greater role in the changeability in mean annual temperature of air. The analysis of formula [2] indicates that great increases and decreases in annual temperature at the discussed stations will be observed in a k year if the values of Tw in two following years are significantly higher or lower than the mean ones. That is why the occurrence of positive trend in value of Tw should be followed by relatively systematic increase in annual air temperature at stations located at the described region. A positive trend in annual air temperature was noted at the analysed stations over the period 1982?2002. At Jan Mayen its value is +0.067 (ą0.028)°C/year (p<0.026). When taking the estimated values of regression coefficients in the multiple regression connecting the annual temperature at Jan Mayen with the value of Tw (Table 1) and the same value of trend T equal to +0.023 then the value of annual trend in air temperature at Jan Mayen influenced by trend Tw equals 0.0598°C/year. The obtained result indicates that the whole or almost whole warming observed at Jan Mayen in the years 1983-2002 may be explained by direct and indirect influence of the increase in the value of Tw over that period.
Źródło:
Problemy Klimatologii Polarnej; 2004, 14; 69-78
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coreless winters in the European sector of the Arctic and their synoptic conditions
Autorzy:
Bednorz, Ewa
Fortuniak, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2051467.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Arctic
North Atlantic
Svalbard
winter air temperature
circulation
polarclimate
Źródło:
Polish Polar Research; 2012, 1; 19-34
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Air temperature variability in the vertical profile over the coastal area of Petuniabukta, central Spitsbergen
Autorzy:
Ambrožová, Klára
Kamil Láska
Powiązania:
https://bibliotekanauki.pl/articles/2046778.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
air temperature inversion
Arctic
near-surface lapse rate
Svalbard
Źródło:
Polish Polar Research; 2017, 38, 1; 41-60
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ zmian temperatury wód w Bramie Farero-Szetlandzkiej na temperaturę powietrza w Arktyce (1950-2005)
The influence of changes of the water temperature in the Faeroe-Shetland Channel on the air temperature in Arctic (1950-2005)
Autorzy:
Marsz, A. A.
Przybylak, R.
Styszyńska, A.
Powiązania:
https://bibliotekanauki.pl/articles/260775.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
temperatura powierzchni oceanu
temperatura powietrza
Brama Farero-Szetlandzka
Prąd Norweski
Arktyka
sea surface temperature
air temperature
Faeroe-Shetland Channel
Norwegian Current
Arctic
Opis:
Praca analizuje związki między wskaźnikiem charakteryzującym zasoby ciepła w wodach atlantyckich wprowadzanych do Prądu Norweskiego, a dalej przez Prąd Zachodniospitsbergeński i Prąd Nordkapski do Arktyki, a roczną temperaturą powietrza w Arktyce. Analizę związków przeprowadzono dla Arktyki jako całości oraz jej sektorów: atlantyckiego, syberyjskiego, pacyficznego kanadyjskiego i sektora Morza Baffina. Wykazano istnienie silnie rozciągniętych w czasie (od 0 do 9 lat opóźnienia) związków z temperaturą powietrza w całej Arktyce, potwierdzających istotny statystycznie wpływ zmian zasobów ciepła w wodach na zmiany temperatury powietrza w Arktyce. Związki regionalne wykazują silne zróżnicowanie - na wzrost zasobów ciepła niemal natychmiastowo reaguje temperatura powietrza w Arktyce Atlantyckiej, z 2-6 letnim opóźnieniem temperatura powietrza w Arktyce Kanadyjskiej. Związki z temperaturą powietrza w sektorach syberyjskim i pacyficznym nie przekraczają progu istotności statystycznej. Zmiany temperatury powietrza w sektorze Morza Baffina wyprzedzają w czasie zmiany zasobów ciepła w wodach atlantyckich wprowadzanych następnie do Arktyki. To ostatnie może stanowić przyczynę okresowości w przebiegu temperatury powietrza w niektórych częściach Arktyki i strefy umiarkowanej.
Styszyńska (2005, 2007) has shown the existence of clear statistical relationships between heat contents in the waters of the Atlantic flowing towards the Arctic via the Norwegian, West Spitsbergen, and North Cape currents and the air temperature in Spitsbergen, Jan Mayen and Hopen between the years 1982 and 2002. These relationships extend in time: following rises in the heat content of the waters of the Norwegian Current, an increase in air temperature follows in the same year and the following year. Heat contents in the Atlantic waters flowing towards the Arctic are assessed according to the average sea surface temperature (SST) in the Faeroe-Shetland Channel (grid 62°N, 004°W) from January to April. These values are used to calculate a determining indicator such as FS1-42L, established as the average of two successive years: data from one year (k) and the year preceding it (k-1). The aim of this work is to investigate whether there are relationships between FS1-42L and the air temperature in both the whole of the Arctic and in individual Arctic sectors and, if so, what the character of these relationships is. The data analysed were a set of yearly air temperatures for the whole of the Arctic and for particular Arctic sectors (fig. 2) according to Przybylak (2007), as well as a set of monthly SST values including values calculated for the FS1-42L indicator (NOAA NCDC ERSST v.1; Smith and Reynolds, 2002). The primary methodology employed was Cross-Correlation Function Analysis. The FS1-42L was established as a first value, with the yearly air temperature used as a lagged value. The analysis was carried out for a 55-year period, from 1951 to 2005. The analysis showed that, taken as a whole, relationships between heat contents leading to the Arctic and air temperature over the whole of the Arctic (calculated from averages of individual sectors) were not particularly significant, though there was marked significance in these relationships from year 0 (fig. 3) to year +9 (fig. 4). The strongest relationships were those from the same year for which the FS1-42L was dated, after which relationships grew gradually weaker, until they finally disappeared in the tenth year. In the Atlantic sector of the Arctic the relationship was strong and almost immediate (fig 5). In the Siberian (fig. 6) and Pacific (fig. 7) sectors there was an absence of statistically significant relationships, and any that did exist were weak, with varying degrees of ?echo? in air temperature reactions. Air temperature in the Canadian sector (fig. 8) reacted to increases in heat contents with a delay of 2 to 6 years, with the strongest relations from FS1-42L being noted with a 5-year delay. The situation in Baffin Bay was entirely different, with air temperature changes preceding changes in the heat contents of the waters of the Faeroe-Shetland Channel by 1 to 6 years. The maximum strengths of these relations were -5 and -4 per year (fig. 9). Analysis of the reasons for these regional variations in the influence of FS1-42L on air temperature allows us to conclude that a major role is played by the bathymetry of the Arctic Ocean. Atlantic waters sinking beneath Arctic Surface Water (ASW) contribute to changes in the temperature of Arctic Intermediate Water (AIW). Independent of the routes taken by the processes, the influence of AIW on the air temperatures in the Siberian and Pacific sectors is limited, with these sectors being isolated by wide shelves from the Arctic Ocean. In the Canadian sector, which is separated by narrow shelves from deep-water parts of the Arctic Ocean and is situated a relatively short distance from the Atlantic sector, the influence of heat contents on the ASW is apparent, with a certain delay. Changes in the air temperature of the Baffin Bay sector are related to the variable activity of the Labrador Current, bringing cold waters to the North from the Gulf Stream delta. The force of strong cooling waters from the Labrador Current, with the appropriate delay, result in a lessening of the heat contents in the Faroe-Shetland Channel. Because of the fact that there is a strong positive correlation between the yearly air temperatures of the Canadian and Baffin Bay sectors, a chain of dependencies emerges: air temperature in the American sectors of the Arctic the flow of Atlantic waters FS1-42L air temperature in the Atlantic Arctic sector Ž air temperature in the Canadian sector should generate quasi-periodic (> 10 years) air temperature courses.
Źródło:
Problemy Klimatologii Polarnej; 2007, 17; 45-59
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oceanic control of the warming processes in the Arctic - a different point of view for the reasons of changes in the Arctic climate
Kontrola oceaniczna procesów ocieplenia Arktyki - odmienny punkt spojrzenia na przyczyny zmian klimatu w Arktyce
Autorzy:
Marsz, A. A.
Styszyńska, A.
Powiązania:
https://bibliotekanauki.pl/articles/260709.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
Arktyka
delta Golfsztromu
ocieplenie
temperatura powietrza
temperatura powierzchni wody
czynniki naturalne
Arctic
Gulf Stream delta
warming
air temperature
SST
natural factors
Opis:
The paper describes the strong correlation between the sea surface temperature (SST) in the region of the Gulf Stream delta and anomalies in surface air temperature (SAT) in the Arctic over the period 1880-2007. This correlation results from the transfer of a variable amount of heat from the Atlantic tropics into the Arctic through oceanic circulation (AMO – Atlantic Multidecadal Oscillation). Reaction of sea ice is the main mechanism controlling the heat content in water carried to the Arctic and influencing the SAT. Sea ice may either increase or limit the heat flow from the ocean to the atmosphere. The genesis of the ‘Great warming of the Arctic’ in the 1930s and ‘40s is the same as that of the present day. Both may be considered to be attributable to natural processes and are not demonstrably associated in any way with a supposed ‘Global greenhouse effect’. Changes in the concentration of CO2 in the atmosphere could only explain 9% of variations in the SAT in the Arctic.
Praca wykazuje istnienie silnych związków między temperaturą powierzchni morza (SST) w rejonie delty Golfsztromu a przebiegiem anomalii temperatury powietrza w Arktyce (1880-2007). Związki te wynikają z transportu przez cyrkulację oceaniczną (AMO – Atlantic Multidecadal Oscillation) zmiennych ilości ciepła z rejonu atlantyckich tropików do Arktyki. Głównym mechanizmem regulującym wpływ zasobów ciepła w wodach wnoszonych do Arktyki na temperaturę powietrza jest reakcja lodów morskich, zwiększająca lub ograniczająca strumienie ciepła z oceanu do atmosfery. Geneza wielkiego ocieplenia Arktyki w latach 30-40. XX wieku i współczesnego ocieplenia Arktyki jest taka sama. Oba epizody ocieplenia Arktyki stanowią rezultat działania procesów naturalnych i nie są związane z dzia-łaniem efektu cieplarnianego. Zmiany koncentracji CO2 w atmosferze objaśniają około 9% wariancji SAT w Arktyce.
Źródło:
Problemy Klimatologii Polarnej; 2009, 19; 7-31
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany pokrywy lodów morskich Arktyki na przełomie XX i XXI wieku i ich związek z cyrkulacją atmosferyczną
Changes in the sea ice cover in the Arctic at the turn of the 20th and 21st centuries and their correlation with the atmospheric circulation
Autorzy:
Marsz, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/260733.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
Arktyka
cyrkulacja atmosferyczna
dipol arktyczny
lody morskie
dryf lodów
temperatura powietrza
Arctic
atmospheric circulation
Arctic Dipole
sea ice
drifting ice
air temperature
Opis:
W pracy dokonano analizy wpływu cyrkulacji atmosferycznej na obserwowane w ostatnich latach XX i pierwszych latach XXI wieku zmiany powierzchni lodów morskich w Arktyce oraz zmian temperatury powietrza w sektorze wschodniosyberyjskim i pacyficznym Arktyki. Wprowadzono nowy wskaźnik charakteryzu-jący cyrkulację atmosferyczną w basenie Morza Arktycznego – zmodyfikowany dipol arktyczny (zDA), będący miesięczną różnicą ciśnienia między rejonem Morza Beauforta a rejonem Tajmyru. Występowanie dodatnich faz zDA porządkuje i przyspiesza dryf lodów z mórz Wschodniosyberyjskiego, Czukockiego i zachodniej części Morza Beauforta oraz centralnych części Morza Arktycznego w kierunku Cieśniny Frama. Po roku 1999 gwałtownie wzrosła częstość występowania ekstremalnie dodatnich faz zDA, wydłużył się również czas ich występowania. W latach 1979-2007 zmiany charakteru cyrkulacji atmosferycznej opisanej przez zDA objaśniają ~42% zmienności rocz-nej powierzchni lodów w Arktyce i 46% zmienności powierzchni zlodzonej we wrześniu, czyli miesiącu, w którym zaznacza się minimum rozwoju lodów morskich. We wschodnich sektorach Arktyki działanie zDA pociąga za sobą wzrost częstości i intensywności adwekcji z południa, co powoduje również wzrost temperatury powietrza. Oszacowano, że gwałtowny wzrost wartości zDA, jaki nastąpił w roku 2007 wymusił, wraz ze zmniejszeniem się powierzchni lodów morskich, wzrost temperatury powietrza na stacjach wybrzeża Morza Czukockiego o ~1.3°C, na Morzu Beauforta o ~1.5°C. Taki stan wskazuje, że obecnie obserwowany gwałtowny spadek powierzchni lodów morskich w Arktyce nie stanowi rezultatu działania efektu cieplarnianego, lecz wzrost temperatury powietrza i spadek powierzchni lodów stanowi rezultat zachodzących zmian w cyrkulacji atmosferycznej nad Arktyką.
The observed, at the turn of the 20th and 21st centuries, rapid decrease both in sea ice extent and its area in the Arctic raise a question regarding the real spectrum of reasons influencing this process. A number of works indicate that the increase in the air temperature in the Arctic resulting from the greenhouse effect, is not responsible for the decrease in sea ice cover but the reduction of the ice cover is one of the main causes of the increase in temperature. The aim of this article is to analyse the influence of atmospheric circulation on the process of reduction of the sea ice cover area in the Arctic in the same period. The break of the so far observed correlations between the AO and air temperature (see Overland and Wang 2005, Graversen 2006, Maslanik et al. 2007) indicates that the reason for the decrease in sea ice area should be searched in the activity of other circulation patterns than AO. Starting with the Wu, Wang and Walsh notion of the Arctic Dipole and carrying out simulation of the directions and rate of the drifting ice, a conclusion can be drawn that a simple index being a modification of the ‘Arctic Dipole’ formulated by Wu et al. 2006 (notation zDA) can be used to describe the maximum effectiveness of the transport of ice from the Arctic and the ‘cleaning’ of the Pacific Arctic from ice (the East Siberian, Chukcha and Beaufort seas). This index can be calculated as a standardised difference between SLP between the Beaufort Sea centre and the Tajmyr centre (see Fig. 4). The presence of strong positive phases of zDA (see Fig. 5) is followed by a rapid increase in the export of ice from the Arctic and results in the decrease in the amount of many-year ice in the structure of the Arctic sea ice cover. The ice is then moved away from the coast of east Siberia and Alaska and equally fast moves along the great circle, along the Transarctic Current reaching the Fram Strait at the end. The presence of strong negative phase of zDA (see Fig. 5B) and the neutral phase (see Fig. 5C) creates favourable conditions for the increase in many-year ice in the sea ice cover and restricts the export of ice from the Arctic. In the period between 1949-2007 a gradual increase in time with the extreme positive phases of zDA (zDA . 1 .n) is observed, and the especially strong increase in the frequency of occurrence of extremely positive phases of zDA is noted in the years of the 21st century (see Fig. 6 and 7). The coefficient of correlation between sea ice extent in the Arctic in August and the number of months in a year with anomalously positive phases of zDA is equal –0.62 (p < 0.001, n = 27; 1979-2007). The same correlation with the annual ice area in the Arctic equals (–0.50, p < 0.008). The analysis of correlation of monthly differences in pressure (non-standardized) between the centre of the Beaufort Sea and the centre of the Tajmyr (notation DP) and the ice area in the Arctic indicates that statistically significant correlations occur if the periods they are averaged for, are longer (see Table 1). The condition is that the averaged period DP started earlier than the averaged sea ice area. The analysis of regression shows that in order to obtain a good model describing minimal (September) or mean annual sea ice extent in the Arctic the DP values from March, when the sea ice extent is the largest, should be taken into consideration as one of the independent variables. This gives explanation of the situation that for longer reduction of sea ice area during the summer season, atmospheric circulation favourable for ice export must appear with great advance (equations [1] and [2]). Changes in DP in the years 1979-2007 explain 42% of variances of mean annual sea ice area and 46% of minimal variances (September) in ice area in the Arctic. As the changes in sea ice area are controlled by the auto-regression process, the occurrence of the increased frequency of extremely positive zDA phases in the following years starting from 1988 (see Fig. 7), especially intensive in the years 2003, 2005 and 2007 resulted in the extreme record of minima of sea ice area, not noted before. The atmospheric circulation described with zDA index forces the flow of air from the south to the Beaufort, Chukcha, East Siberian and Laptev seas (see Fig. 5A and Fig. 14). This direction of advection should lead to the increase in surface air temperature (SAT) over the coasts of the above mentioned sea areas. Strong increases in annual SAT can be observed at the stations located on the coasts of the above mentioned seas. The monthly distribution of SAT values indicates especially strong increases in the months from the end of summer and autumn (see Fig. 10-12). The analysis of correlations between DP and monthly SAT at the stations located in that part of the Arctic (see Table 2) indicates the presence of generally weak correlations between the monthly values of DP and SAT. During winter season at the stations located in the western part of the analysed region (Laptev Sea: Kotielyj Island, Mys Shalaurov) the correlations are negative which means that with the increase in differences of pressure between the region of the Beauforf Sea and the region of the Tajmyr (increase zDA) SAT decreases there (in January these correlations are statistically significant). This state can be explained as resulting from advection of air cooled to a great extent over the Siberia. Positive correlations between SAT and DP can be observed at the remaining stations in December, January and February, i.e. in the period when the short wave radiation is scarce, almost null or null and the solid/fast ice reaches the coast line. There is no other explanation of this phenomenon then as the effect of advectional increase in temperature. Similar positive correlations between DP (and in this way also zDA) and the air temperature are observed over the entire analysed region in the summer months and at the beginning of autumn (July-September). At a number of stations in particular months these correlations are statistically not significant, reaching their maximum value at Vrangel Island (in August; r = +0.6; see Fig. 13). As the analysis indicates the summer and early autumn correlations are the direct effect of advection as well as indirect effect of zDA resulting in the area in the coastal waters free from ice. The increase in zDA is accompanied by the visible increase in SST in the summer and early autumn months, which consequently results in the increase in SAT in October. If the correlations between monthly temperature and DP are statistically significant then it is possible to carry out the analysis of regression. This analysis indicates that in the year 2007 in which zDA reached in the period from April to September extremely high values (see Fig.14), the increase in SAT which is influenced by atmospheric circulation, can be estimated as +0.9°C at Vrangel Island and +1.5°C in relation to mean many-year value at Barrow station. Thus, the influence of the atmospheric circulation defined by the zDA index in the Pacific sector of the Arctic indicates synergy – results both in the decrease in the sea ice area as well as in the increase in air temperature. Large restriction of sea ice area over summer season in these sea areas intensifies, in turn, the increase in SAT. The carried out analysis indicates that the observed changes in the area and age structure of the sea ice in the Arctic at the turn of the 20th and 21st centuries and during the first years of the 21st century are mainly connected with the activity of natural processes. The role of the greenhouse effect controlling the changes in sea ice cover of the Arctic, as the analysis shows, has been overestimated.
Źródło:
Problemy Klimatologii Polarnej; 2008, 18; 7-33
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany zlodzenia Morza Karskiego w latach 1979-2015. Podejście systemowe
Changes of sea ice extent on the Kara Sea in the years 1979-2015. System approach
Autorzy:
Styszyńska, A.
Marsz, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/260907.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
pokrywa lodowa
zmiany powierzchni lodów
THC
temperatura powietrza
temperatura wody powierzchniowej
Morze Karskie
Arktyka
Atlantyk Północny
ice cover
changes in sea-ice extent
air temperature
sea surface temperature
Kara Sea
Arctic
North Atlantic
Opis:
Praca omawia zmiany powierzchni lodów na Morzu Karskim i mechanizmy tych zmian. Scharakteryzowano przebieg zmian zlodzenia, ustalając momenty skokowego zmniejszenia się letniej powierzchni lodów. Rozpatrzono wpływ cyrkulacji atmosferycznej, zmian temperatury powietrza i zmian zasobów ciepła w wodach na zmiany zlodzonej tego morza. Analizy wykazały, że wszystkie zmienne opisujące zarówno stan zlodzenia jak i stan elementów klimatycznych są ze sobą wzajemnie powiązane przez różnego rodzaju sprzężenia zwrotne. W rezultacie tworzy się rekurentny system, w którym zmiany powierzchni lodów, wpływając na przebieg innych elementów systemu (temperaturę powietrza, temperaturę wody powierzchniowej) w znacznej części same sterują swoim rozwojem. Zmiennością całego tego systemu sterują zmiany intensywności cyrkulacji termohalinowej (THC) na Atlantyku Północnym, dostarczając do niego zmienne ilości energii (ciepła). Reakcja systemu zlodzenia Morza Karskiego na zmiany natężenia THC następuje z 6.letnim opóźnieniem.
The work discusses the changes in the ice extent on the Kara Sea in the years 1979-2015, i.e. in the period for which there are reliable satellite data. The analysis is based on the average monthly ice extent taken from the database AANII (RF, St. Peterburg). 95% of the variance of average annual ice extent explains the variability of the average of ice extent in ‘warm' season (July-October). Examination of features of auto-regressive course of changes in ice extent shows that the extent of the melting ice area between June and July (marked in the text RZ07-06) can reliably predict the ice extent on the Kara Sea in August, September, October and November as well as the average ice extent in a given year. Thus the changes in ice extent can be treated as a result of changes occurring within the system. Analysis of the relationship of changes in ice extent and variable RZ07-06 with the features of atmospheric circulation showed that only changes in atmospheric circulation in the Fram Strait (Dipole Fram Strait; variable DCF03-08) have a statistically significant impact on changes in ice extent on the Kara Sea and variable RZ07-06. The analysis shows no significant correlation with changes in ice extent or AO (Arctic Oscillation), or NAO (North Atlantic Oscillation). Variable RZ07-06 and variable DCF03-08 are strongly correlated and their changes follow the same pattern. Analysis of the relationship of changes in ice extent and variable RZ07-06 with changes in air temperature (the SAT) showed the presence of strong relationships. These correlations differ significantly depending on the region; they are much stronger with changes in air temperature in the north than in the south of the Kara Sea. Temperature of cold period (average temperature from November to April over the Kara Sea, marked 6ST11-04) has a significant effect on the thickness of the winter ice and in this way the thickness of ice in the next melting season becomes part of the "memory" (retention) of past temperature conditions. The thickness of the winter ice has an impact on the value of the variable RZ07-06 and on changes in ice extent during the next ‘warm’ season. As a result, 6ST11-04 explains 62% of the observed variance of the annual ice extent on the Kara Sea. SAT variability in the warm period over the Kara Sea (the average of the period July-October, marked 6ST07-10) explains 73% of the variance of annual ice extent. SAT variability of the N part of the Kara Sea (Ostrov Vize, Ostrov Golomjannyj), which explains 72-73% of the variance ice extent during this period, has particularly strong impact on changes in ice extent during warm period. These stations are located in the area where the transformed Atlantic Waters import heat to the Kara Sea. Analysis of the impact of changes in sea surface temperature (SST) variability on sea ice extent indicated that changes in SST are the strongest factor that has influence on ice extent. The variability of annual SST explains 82% of the variance of annual ice extent and 58% of the variance of the variable RZ07-06. Further analysis showed that the SAT period of warm and annual SAT on the Kara Sea are functions of the annual SST (water warmer than the air) but also ice extent. On the other hand, it turns out that the SST is in part a function of ice extent. All variables describing the ice extent and its changes as well as variables describing the nature of the elements of hydro-climatic conditions affecting the changes in ice extent (atmospheric circulation, SAT, SST) are strongly and highly significantly related (Table 9) and change in the same pattern. In this way, the existence of recursion system is detected where the changes in ice extent eventually have influence on ‘each other’ with some time shift. The occurrence of recursion in the system results in very strong autocorrelation in the course of inter-annual changes in ice extent. Despite the presence of recursion, factors most influencing change in ice extent, i.e. the variability in SST (83% of variance explanations) and variability in SAT were found by means of multiple regression analysis and analysis of variance. Their combined impact explains 89% of the variance of the annual ice extent on the Kara Sea and 85% of the variance of ice extent in the warm period. The same rhythm of changes suggests that the system is controlled by an external factor coming from outside the system. The analyses have shown that this factor is the variability in the intensity of the thermohaline circulation (referred to as THC) on the North Atlantic, characterized by a variable marked by DG3L acronym. Correlation between the THC signal and the ice extent and hydro-climatic variables are stretched over long periods of time (Table 10). The system responds to changes in the intensity of THC with a six-year delay, the source comes from the tropical North Atlantic. Variable amounts of heat (energy) supplied to the Arctic by ocean circulation change heat resources in the waters and in SST. This factor changes the ice extent and sizes of heat flux from the ocean to the atmosphere and the nature of the atmospheric circulation, as well as the value of the RZ07-06 variable, which determines the rate of ice melting during the ‘warm’ season. A six-year delay in response of the Kara Sea ice extent to the THC signal, compared to the known values of DG3L index to the year 2016, allows the approximate estimates of changes in ice extent of this sea by the year 2023. In the years 2017 to 2020 a further rapid decrease in ice extent will be observed during the ‘warm' period (July-October), in this period in the years 2020-2023 ice free conditions on the Kara Sea will prevail. Ice free navigation will continue from the last decade of June to the last decade of October in the years 2020-2023. Since the THC variability includes the longterm, 70-year component of periodicity, it allows to assume that by the year 2030 the conditions of navigation in the Kara Sea will be good, although winter ice cover will reappear.
Źródło:
Problemy Klimatologii Polarnej; 2016, 26; 109-156
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 16

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