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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:
Ultrasonic Measurement of Temperature Rise in Breast Cyst and in Neighbouring Tissues as a Method of Tissue Differentiation
Autorzy:
Gambin, B.
Byra, M.
Kruglenko, E.
Doubrovina, O.
Nowicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/177465.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
medical ultrasound
temperature changes in vivo
breast tissue
ultrasonic temperature measurement
Opis:
Texture of ultrasound images contain information about the properties of examined tissues. The analysis of statistical properties of backscattered ultrasonic echoes has been recently successfully applied to differentiate healthy breast tissue from the benign and malignant lesions. We propose a novel procedure of tissue characterization based on acquiring backscattered echoes from the heated breast. We have proved that the temperature increase inside the breast modifies the intensity, spectrum of the backscattered signals and the probability density function of envelope samples. We discuss the differences in probability density functions in two types of tissue regions, e.g. cysts and the surrounding glandular tissue regions. Independently, Pennes bioheat equation in heterogeneous breast tissue was used to describe the heating process. We applied the finite element method to solve this equation. Results have been compared with the ultrasonic predictions of the temperature distribution. The results confirm the possibility of distinguishing the differences in thermal and acoustical properties of breast cyst and surrounding glandular tissues.
Źródło:
Archives of Acoustics; 2016, 41, 4; 791-798
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation Studies of Dimensional Accuracy with Temperature Changes of Selected Elements of a Machine Tool in the Machining Process
Autorzy:
Basara, Damian
Skoczylas, Leszek
Powiązania:
https://bibliotekanauki.pl/articles/2022490.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
temperature changes of machine components
FMS
serial production
correlation
Opis:
The article presents the characteristics of temperature changes of selected components of the machine tool and the temperature of the machining coolant in relation to the selected dimensions of finished parts, such as the AGB gear cover. The tests were carried out on the basis of serial production on the FMS line in a plant producing components for the aviation industry. As part of the research, the machine tool was modernized to the extent that it was possible to register temperatures in real-time. Temperature changes were compared with the dimensions of the machined part in search of dependencies. Correlation calculations between temperature and dimensional data were made with the use of a statistical process control program. Dimensional data were obtained from CMM machines used daily to measure parts from series production.
Źródło:
Advances in Science and Technology. Research Journal; 2022, 16, 1; 253-259
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of climate change on vegetation period of basic species of vegetables in Slovakia
Autorzy:
Čimo, Ján
Šinka, Karol
Tárník, Andrej
Aydin, Elena
Kišš, Vladimír
Toková, Lucia
Powiązania:
https://bibliotekanauki.pl/articles/1844399.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
average temperature
basic species of vegetables
climate change
temperature changes
vegetation period
Opis:
The aim of the paper is to provide climatic data from the basic elements and characteristics of the energy balance in terms of the current state and in terms of trends and assumptions of their future changes in Slovakia. Climate change affect agriculture and its procedures. Changes in vegetation period in Slovakia of selected vegetables are presented in this study. We used for agro-climatic analysis one hundred climatological stations, which were selected to cover all agricultural regions up to 800 m a.s.l. Actual data and predictions were compared with time period 1961–2010. Due to homogeneity in data measurements, was chosen this period. We obtained climate trends and assumed map outputs of future climate changes by mathematical-statistical methods for horizons of years 2011–2020, 2041–2050, 2071–2080 and 2091–2100. We analysed vegetation period changes of selected fruit vegetables, Brassica vegetables and root vegetable in field conditions with prediction to year 2100. In our results is shown the earlier beginning of vegetation period in a spring and later end in an autumn in last 30 years. The vegetation period is getting longer about 15–20 days for Capsicum annuum; 15–20 days for Brassica oleracea var. capitate; 10–15 days for Beta vulgaris subsp. vulgaris with comparation of nowadays situation and period 2091–2100.
Źródło:
Journal of Water and Land Development; 2020, 47; 38-46
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of mass matrix forms on numerical simulations results in heat conduction modeling
Autorzy:
Zych, M.
Powiązania:
https://bibliotekanauki.pl/articles/122680.pdf
Data publikacji:
2015
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
heat conduction
temperature changes
matrix
przewodzenie ciepła
zmiany temperatury
macierz
Opis:
The paper presents an analysis of the impact of the mass matrix on the changes in temperature during the computer simulation (using the method of finite elements) of the heat conduction process. The temperature variations of the phenomenon was taken into consideration, which is required during the solidification simulation of binary alloys. It was shown that the smallest oscillation occurs in the lumped matrices in the initial stage of the simulation. The results for lumped and diagonal matrix are mostly equal.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2015, 14, 3; 149-156
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the magnetic particles concentration on the ferro-oil’s dynamic viscosity in presence of an external magnetic field in the aspect of temperature changes
Autorzy:
Czaban, A.
Frycz, M.
Horak, W.
Powiązania:
https://bibliotekanauki.pl/articles/247080.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ferro-oil
dynamic viscosity
magnetic particles concentration
temperature changes
external magnetic field
Opis:
There is presented an effect of the changes of the concentration of magnetic particles included in the ferro-oil on its dynamic viscosity in the presence of external magnetic field in this paper. The study was conducted in the context of temperature’s changes. The authors assume that the concentration of magnetic particles in ferro-oil can significantly affects its basic physical properties as dynamic viscosity, as well as the operational properties of journal sliding bearings ferro-oil’s lubricated. The equally significant as the above mentioned properties may affect the external environmental conditions of operation, especially temperature changes. In this context, an important technique’s issue appears to determine the principles of selection of optimal concentration of above mentioned particles according to the existing environmental conditions of its operation, or the expectations laid against the operation of the devices. Rheological studies were carried out on Physica MCR 301 rheometer in the “plate-to-plate” measurement system with an adapter to magneto-rheological studies MRD 180/1T. Thermal stabilization was carried out by a water jacket in a closed chamber and controlling the nature of the magnetic field was conducted by current’s changes. Tests were performed for four selected temperature range of 60º, 70º, 80º and 90ºC as regards changes an external magnetic field intensity 0-700 mT. The selected concentrations of magnetic particles in a ferro-oil were 1, 2, 4, 6 and 8%.
Źródło:
Journal of KONES; 2013, 20, 2; 55-60
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experiments in Using Face Temperature Changes as an Indicator in Instrumental Detection of Deception
Autorzy:
Mikrut, Zbigniew
Widacki, Michał
Widacki, Jan
Powiązania:
https://bibliotekanauki.pl/articles/523280.pdf
Data publikacji:
2018
Wydawca:
Krakowska Akademia im. Andrzeja Frycza Modrzewskiego
Tematy:
Face temperature changes and selection of deception
infrared camera in detection of deception
Źródło:
European Polygraph; 2018, 12, 3(45); 85-105
1898-5238
2380-0550
Pojawia się w:
European Polygraph
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermomechanical Properties of Vulcanized Rubber investigated by Testing Machine and Infrared Camera
Autorzy:
Staszczak, M
Pieczyska, E. A.
Maj, M.
Urbański, Ł.
Odriozola, I.
Martin, R.
Powiązania:
https://bibliotekanauki.pl/articles/114054.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
vulcanized rubber
self-healing polyurethane
tension test
thermo-mechanical couplings
temperature changes
infrared camera
Opis:
: Experimental results of effects of thermomechanical couplings occurring both in natural vulcanized rubber and rubber with self-healing polyurethane subjected to tension at different strain rates are presented. Mechanical characteristics were recorded by testing machine, while the sample temperature changes accompanying the deformation process was measured by infrared camera. The goal was to investigate influence of self-healing polyurethane on the rubber mechanical and thermomechanical properties. It was found that the introduction of the self-healing polyurethane ensures the higher elasticity and the lower tensile strength of the rubber. It was also confirmed that the material is very sensitive to the strain rate; the higher the strain rate, the higher the values of the stress and temperature increases have been obtained.
Źródło:
Measurement Automation Monitoring; 2015, 61, 6; 206-209
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An annual cycle of changes in water temperature as a cause of cracking in massive concrete hydraulic structures
Roczny cykl zmian temperatury wody jako przyczyna pękania w masywnych konstrukcjach betonowych budowli hydrotechnicznych
Autorzy:
Łydżba, D.
Różański, A.
Sobótka, M.
Powiązania:
https://bibliotekanauki.pl/articles/348677.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
budowla hydrotechniczna
elektrownia wodna
naprężenia cieplne
wpływ temperatury
HPP
hydropower plant
thermal stresses
temperature changes
failure criterion
Opis:
The paper deals with the problem of temperature effect on a massive concrete hydraulic structure. The article is split into two parts. In the first part is an investigation concerning temperature distribution in a concrete wall of a hydraulic structure due to annual changes in water temperature. The conclusion of these considerations is that the temperature distribution in the concrete element, due to slow annual changes in temperature of flowing water, is almost uniform in space. The advantage of this fact is taken into consideration in another part in which the results of a numerical analysis concerning a HPP on the Vistula river is presented. Final conclusion is that water temperature changes can easily cause cracking in concrete hydraulic structures.
W artykule rozważany jest wpływ temperatury na masywne konstrukcje betonowe obiektów hydrotechnicznych. Praca składa się z dwóch zasadniczych części. W pierwszej określany jest rozkład temperatury występujący w betonowej ścianie budowli wodnej na skutek rocznych, wolnych zmian temperatury wody. Wniosek z tych rozważań, tj. że rozkład temperatury wewnątrz elementu betonowego jest prawie jednorodny jest wykorzystany jako założenie w drugiej części pracy. Analizie numerycznej poddana jest jedna z elektrowni wodnych na Wiśle. Z przeprowadzonych obliczeń wynika, że zmiany temperatury wody, występujące w klimacie charakterystycznym dla Polski, mogą prowadzić do powstawania pęknięć w betonowych elementach budowli hydrotechnicznych.
Źródło:
AGH Journal of Mining and Geoengineering; 2012, 36, 2; 217-227
1732-6702
Pojawia się w:
AGH Journal of Mining and Geoengineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Climatological analysis of windstorm from November 2004 and evaluation of its impacts on meso- and microclimatic conditions in the High Tatras Region
Autorzy:
Pecho, J.
Poleák, N.
Powiązania:
https://bibliotekanauki.pl/articles/294605.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Geomorfologów Polskich
Tematy:
windstorm in the High Tatras
meso- and microclimatic condition changes
statistical analysis
air temperature regime changes
snow cover spatial analysis
Opis:
On Friday, November 19th, 2004, a violent windstorm of wasting force hit the High Tatras’forest scrubs. The landscape pattern of the 50 km long and 2.5 km wide area became completely changed by rare meteorological phenomena (the total area of devastated forest scrub was about 12,000 hectares). The forest scrub pattern has been dramatically changed whereby the connected and coherent spruce scrubs at the age between 40 and 110 years have been replaced by the low, mainly meadow vegetation. It is highly probable the radical surface change might have resulted in modification of meso- and microclimatic conditions of the affected region. Apart from this fact, an impact of expected meso- and microclimatic condition changes on regional climate could modify the atmospheric component of the High Tatras environment. For the purpose of identification and quantification of significant scrub change-induced meso-climatic signal, we are dealing with statistical analysis of selected meteorological component time series (air temperature, air humidity, precipitation, wind speed, cloudiness, as well as sunshine duration and snow cover characteristics) at representative climatological stations (Poprad, Štrbské Pleso, Tatranská Lomnica, Stará Lesná, Oravská Lesná, Liptovský Hrádok, etc.) within the 1951–2007 and 1961–2007 period. However, we have not been able to validate any significant changes in air temperature, relative humidity and precipitation regime in the meso-scale climate conditions. Some relevant microclimate modifications of heat and moisture fluxes have been found, according to microclimate monitoring results presented in Matejka & Hurtalová (2008).
Źródło:
Landform Analysis; 2009, 10; 108-114
1429-799X
Pojawia się w:
Landform Analysis
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Występowanie sytuacji meteorotropowych w Polsce w latach 2000-2020
The occurrence and variability of meteotropic situations in Poland in the years 2000-2020
Autorzy:
Chabowska, Monika
Kolendowicz, Leszek
Półrolniczak, Marek
Powiązania:
https://bibliotekanauki.pl/articles/43348943.pdf
Data publikacji:
2022
Wydawca:
Poznańskie Towarzystwo Przyjaciół Nauk
Tematy:
meteotropic situations
very hot days
frosty days
interdiurnal changes of the air temperature
inter-diurnal changes of the atmospheric pressure
insolation
Polska
Opis:
Meteotropic situations are defined as weather that may affect human health and exacerbate diseases, especially in sensitive persons. The main objective of the paper is to determine the occurrence of meteotropic situations in Poland in years 2000–2020. The study took into account the characteristic elements such as very hot days (tmax> 30°C), frosty days (tmax< 0°C), day-to-day changes of mean daily air temperature (Δtśr> 6°C), day-to-day changes of mean daily air pressure (≥ 8 hPa) and days with insolation deficit. The research indicated that the highest heat stress strain is typical of the western and central parts of Poland and the highest low air temperature stimuli intensity of high mountain regions. Then, the highest fluctuations of the air temperature interdiurnal variation are characteristic of high mountain regions with the air pressure interdiurnal changes typical of the coastal region. According to our research, the most frequent meteotropic situation was associated with the insolation deficit occurring mostly in the north-eastern and high mountain regions of Poland.
Źródło:
Badania Fizjograficzne Seria A - Geografia Fizyczna; 2022, 13 (73); 27-44
2081-6014
Pojawia się w:
Badania Fizjograficzne Seria A - Geografia Fizyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany temperatury wody powierzchniowej na morzach Arktyki Rosyjskiej i ich konsekwencje dla żeglugi na Północnej Drodze Morskiej (1979-2016)
Changes of sea surface temperature in the Russian Arctic Seas and their implications for shipping in the Northern Sea Route (1979-2016)
Autorzy:
Styszyńska, A.
Pastusiak, T.
Powiązania:
https://bibliotekanauki.pl/articles/260798.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
temperatura wody powierzchniowej
zmiany temperatury wody
Północna Droga Morska
Arktyka Rosyjska
sea surface temperature
changes in water temperature
Northern Sea Route
Russian Arctic
Opis:
Praca omawia zmiany średniej miesięcznej temperatury wody powierzchniowej na morzach Arktyki Rosyjskiej w latach 1979-2016. Stwierdzono, że w badanym okresie następował powolny wzrost temperatury wody. Jednakże tylko na Morzu Barentsa był on istotny statystycznie we wszystkich miesiącach roku, a w SW części Morza Karskiego oraz w zachodniej części Morza Czukockiego w okresie od czerwca do grudnia. W analizowanym 38.leciu największy wzrost temperatury wody powierzchniowej miał miejsce na Morzu Wschodniosyberyjskim (+0,57°C/10 lat w sierpniu i +0,44°C/10 lat we wrześniu) oraz w SW części Morza Karskiego w lipcu (+0,53°C/10 lat). W dalszym ciągu na wszystkich morzach, poza Morzem Barentsa, do czerwca włącznie temperatura wody ma wartości niższe od temperatury jej zamarzania przy swoistym dla danego morza zasoleniu. Najpóźniej temperaturę zamarzania osiągają wody Morza Barentsa gdzie w ostatniej dekadzie (2006-2015) na podejściu do północnego wejścia na PDM rzadko kiedy temperatura wody spadała poniżej temperatury zamarzania oraz wody Morza Czukockiego (w grudniu). Oznacza to, że statki pokonujące PDM w listopadzie będą miały szansę przepłynąć ją po „czystej” wodzie lub w cienkich, młodych lodach, które dla współczesnych statków nie stanowią większego zagrożenia.
The paper discusses changes of the mean monthly sea surface temperature on the Russian Arctic seas in the years 1979-2016. It was found that during the period under investigation there was a slow increase in water temperature. However, only in the Barents Sea it was statistically significant in all months of the year, and in the SW part of the Kara and western Chukchi seas from June to December. In the analyzed 38 years the highest rise in surface water temperature was recorded in the East Siberian Sea (+0.57°C/decade in August and +0.44°C/decade in September) and in the SW Kara Sea in July (+0.53°C/decade). Still on all these seas, except for the Barents Sea, until June inclusive, the water temperature was lower than its freezing temperature for a particular salinity specific for the sea. At the latest, freezing temperatures reached the waters of the Barents Sea, where in the last decade (2006-2015) at the approach to the north entrance of the Northern Sea Route (NSR) rarely water temperature has fallen below the freezing point. At the same time, the Chukchi Sea waters reached freezing temperatures in December. This means that vessels sailing through the NSR in November will have the chance to pass it through "ice free" water or in thin, young ice, which for modern ships is not a major threat.
Źródło:
Problemy Klimatologii Polarnej; 2016, 26; 165-177
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany warunków termicznych w Pile w latach 1971–2020
Changes in the thermal conditions in Piła in 1971–2020
Autorzy:
Matuszak, Zuzanna
Powiązania:
https://bibliotekanauki.pl/articles/43347431.pdf
Data publikacji:
2020-12-15
Wydawca:
Poznańskie Towarzystwo Przyjaciół Nauk
Tematy:
air temperature
climate changes
thermal classification
thermal seasons
Opis:
The paper focuses on changes of the thermal conditions in Piła in 1971–2020. In the study, daily data were obtained from the Institute of Meteorology and Water Management – the National Research Institute, to analyze the variability of the annual, seasonal and monthly average air temperature, develop a thermal classification and determine the variability of the start dates and the length of 6 thermal seasons. The analysis showed an increase in the average air temperature for all of the time intervals. The consequence of the progressive warming was the increasingly frequent occurrence of months, seasons and years with thermal conditions above the norm for the entire studied period. The research also showed statistically significant changes in the dates of the beginning of the spring, summer, autumn and early winter, with the highest trend in the autumn.
Źródło:
Badania Fizjograficzne Seria A - Geografia Fizyczna; 2020, 11 (71); 75-94
2081-6014
Pojawia się w:
Badania Fizjograficzne Seria A - Geografia Fizyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of build-up areas and housing estate vegetation on diversity of the local climate in Warsaw
Autorzy:
Stopa-Boryczka, Maria
Boryczka, Jerzy
Wawer, Jolanta
Miłaszewska, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/2034158.pdf
Data publikacji:
2010-06-01
Wydawca:
Uniwersytet Warszawski. Wydział Geografii i Studiów Regionalnych
Tematy:
Intensity of heat island
diurnal changes
annual changes
air temperature
latitudinal profiles
town
Opis:
The more important research results on the impact of building development and vegetation on the local climate, conducted in Warsaw in the years 1959-2009 by the Department of Climatology, are presented. Majority of the issues associated with determining the deformation of air temperature limits (urban heat islands), humidity and wind vector areas, because of buildings in housing estates, located in various parts of the city, were resolved in master's thesis. Areas with high building density are characterized by slow cooling and warming pace, especially during the summer months. Spatial changes in the urban heat islands in the east-west direction well describe the latitudinal profiles (W-E) of air temperature differences (∆T ≥ 0) between the city and its urban fringe. The urban heat island ∆T does not appears till 5PM, initially in the Central City District. Spatial diversity of effective temperature and catathermal cooling allowed to mark off in housing estates ( „Stawki”, „Służew nad Dolinką”, „Sady Żoliborskie”) places with perceptible conditions, e.g. heat, warmth, comfort, cold.
Źródło:
Miscellanea Geographica. Regional Studies on Development; 2010, 14; 121-134
0867-6046
2084-6118
Pojawia się w:
Miscellanea Geographica. Regional Studies on Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
O "arktycznych" i "atlantyckich" mechanizmach sterujących zmiennością temperatury powietrza na obszarze Europy i północo-zachodniej Azji
On "Arctic" and "Atlantic" mechanisms controlling the changeability in air temperature in the region of Europe and NW Asia
Autorzy:
Marsz, A. A.
Styszyńska, A.
Powiązania:
https://bibliotekanauki.pl/articles/260919.pdf
Data publikacji:
2006
Wydawca:
Stowarzyszenie Klimatologów Polskich
Tematy:
zmiany temperatury powietrza
zmiany temperatury wody powierzchniowej
NAO
Oscylacja Eurazjatycka
AO
Arktyka Atlantycka
NW Azja
Europa
Atlantyk Północny
NW Asia
Europe
changes in pressure
changes in air temperature
Opis:
Praca omawia wpływ zmian ciśnienia atmosferycznego w Arktyce Atlantyckiej (dalej AA) na kształtowanie zmienności temperatury powietrza na obszarze Europy (na N od 40°N) i NW Azji (do 120°E). Wpływ zmian ciśnienia w AA na temperaturę powietrza zaznacza się we wszystkich, z wyjątkiem czerwca, miesiącach roku, tworząc charakterystyczny cykl z maksimum siły oddziaływania zimą. Zimowe (01-03) zmiany ciśnienia w AA objaśniają od kilkunastu do ponad 60% zmienności temperatury rocznej (z maksimum na obszarze wokół-bałtyckim; 1951-2000). W pracy analizuje się współdziałanie zmian ciśnienia w Arktyce Atlantyckiej ze zmianami ciśnienia w Wyżu Syberyjskim w kształtowaniu zmienności temperatury powietrza na obszarze Europy i NW Azji. Dyskutuje się również kwestie związków zmian ciśnienia w AA z NAO, AO oraz frekwencją makrotypów cyrkulacji środkowotroposferycznej wg klasyfikacji Wangengejma-Girsa. Wyniki analiz wykazują, że o zimowych zmianach ciśnienia w AA decyduje wcześniejszy rozkład zasobów ciepła w wodach Atlantyku Północnego.
The research on relations between climatic elements of Europe and the Arctic has indicated that there are significant correlations between changes in atmospheric pressure in the Atlantic part of the Arctic and air temperature in northern Europe and NW Asia. The strongest correlations are observed between changes in pressure over relatively small area of the Atlantic part of the Arctic (72.5 - 80.0°N, 10.0 - 25.0°E), in addition, the point over which changes in pressure explain most of changes in air temperature is located 75.0°N, 015.0°E. Pressure at this point is further referred as P[75,15] with an index denoting a month (e.g. P[75,15]03 denotes mean pressure in March and P[75,15]01-03 defines mean pressure at this point from the period January till March). Over the Atlantic part of the Arctic within the pressure area there is no marked climatic centre which could be regarded as the centre of atmospheric activity. The research made use of monthly series of SLP values (reanalysis: set NOAA.NCEP-NCAR. CDAS-1.MONTHLY.Intrinsic.MSL.pressure) and the values of monthly air temperature from 211 stations (Fig. 1). The observational period common for both elements covers 50 years, i.e. the period from January 1951 to December 2000. The character of correlations between P[75,15] and air temperature in the following months, from June to May, and their spatial distribution have been presented by isocorrelates maps (Fig. 2). Changes in the strength of correlations between P[75,15] and the temperature over Europe and NW Asia form a clear annual cycle interrupted in June. In June the correlations between P[75,15] and air temperature became very weak and not significant over the most of the area and not continuous in space. During the months after June these correlations got stronger and stronger reaching their maximum during cold season (from November to April). This maximum is located in the region adjacent to the Baltic Sea, where annual and winter (01-03) changes in P[75,15] explain from more than 60% to 50% of annual temperature variances (Fig. 3) The strongest correlation between P[75,15] and air temperature in Siberia is located N of Baikal, where winter (01-03) changes in P[75,15] explain 43-45% of annual temperature variances. At the end of the cold season a visible delay of the decrease in the strength of correlation is observed in the region of Siberia in relation to the European region (in Europe after March, in Siberia after April). Variability in winter and annual values of pressure at 75°N, 015°E also indicates relatively strong correlations with the changeability in temperature of the warmest month in the year in the west and central region of Europe. The annual variability in P[75,15] explains from 40% to 30% changeability of maximum temperature in the region extending from the Atlantic coast of France to central Germany. This belt extends farther east towards the Baltic Sea. The latter correlation has not been explained in this work. The analysis of correlations of changes in pressure at 75°N, 15°E with NAO indicates to the occurrence of statistically significant correlations during months of cold season in the year (October - March, May and June; Tab. 2). Similar analysis of correlations of changes in P[75,15] with AO index (Arctic Oscillation) shows strong and highly statistically significant correlations in all months of the year with maximum falling in January and February. Annual changes in P[75,15], i.e. in pressure at one point explain 73% annual changeability in AO index (r = 0.86) and the winter changeability in (December - March) P[75,15] explains 78% of winter changeability in AO index (r = 0.88) which is the first vector EOF of pressure field (1000 hPa) covering the area from 20°N to the North Pole (90°N), that is the most area of the Northern Hemisphere. This analysis shows that the changes in pressure at the point 75°N, 15°E result in intensification of cyclogenesis over west and central part of the North Atlantic and the consequent long waves (waves of W type following Wangengejm-Girs classification) cause that anticyclones formed over the Atlantic will direct towards Fram Strait through the region of Iceland. The above process has nothing or almost nothing to do with the form of changeability in polar strato-spheric eddy, as assumed by Tomphson and Wallace (1998, 2000, Thompson, Wallace, Hegerl 2000) to be essential for the Arctic Oscillation functioning. Occurrence of correlations between P[75,15] and air temperature over vast areas from 10°W to 130°E suggests that also changes in pressure in the Siberian High are engaged in this process. Theanalysis shows that in a yearly process, changes in pressure in the Atlantic part of the Arctic and in the Siberian High occur in opposite phases (see Tab.1). Barometric gradient between the Atlantic part of the Arctic and the Siberian High becomes extremely strong during the cold season of the year contributing to "pumping" air from eastern Europe to the far end of the Siberia. During the summer season the gradient becomes very weak as the about-turn takes place. The cooperation of changes in pressure in the Atlantic part of the Arctic and pressure in region located farther Baikal -- Mongolia results in very strong oscillation which partly can be identified with Euro-Asian Oscillation (Monahan et al. 2000). During winter season interannual changes in pressure in the Siberian High are relatively small and explain 10.4% variances of barometric gradient between P[75,15] and point 45°N, 110°E (the region of the centre of the Siberian High), whereas the interannual changes in P[75,15] explain 77.5% of variances in this gradient. This means that in the cold season of the year the intensity of air transfer from the west towards Asian land depends on variability in pressure in the Atlantic part of the Arctic. Because in the months of the cold season of the year NAO is the strongest and significantly correlated with changes in P[75,15] therefore, a two-element, with the same phase "conveyor belt" is formed, which during positive phases of NAO transfers the air from over the Atlantic to Europe (NAO) and then towards and into the Siberia (Euro-Asian Oscillation). P[75,15] during cold season months of the year (01-03) indicates statistically significant negative trend (-0.153 hPa/year; p < 0.006) which enables to state that the observed, over the years 1951-2000, increase in air temperature in the Siberia can be, in great extent, attributed to the activity of the above described circulation mechanism. The analysis of reasons for interannual changes in P[75,15] has indicated that there are strong and significant correlations between variability in P[75,15] and the earlier variability in the thermal conditions of the Atlantic Ocean. A very important role in this relation plays thermal condition of three sea areas, i.e. waters of the subtropical region of central part of the North Atlantic (characterized by SST anomalies in grid 34°N, 40°W from August and September), waters of the middle latitudes zone of the central part of the North Atlantic (characterized by SST anomalies from August and September in grid 54°N, 30°W) and waters of the North Atlantic Current from the approach to the Farero-Shetland Passage (characterized by SST anomalies from January and April in grid 60°N, 10°W). Thermal state of these three sea water areas (see formulas [1] and [2]) explains 58% changeability in P[75,15] which will be observed in the following winter (DJFM). The cause of the described correlation is attributed to the fact that the earlier thermal state of the above mentioned sea areas controls the occurrence of long waves, of W and E Wangengejm-Girs type during the following winter. Further, these waves influence the occurrence of low cyclones over the Atlantic part of the Arctic during winter resulting in adequate changes in mean monthly pressure. As a result, it can be stated that the interannual variability in air temperature over vast areas of Europe and over NW Asia is influenced by the processes observed over the North Atlantic and the Atlantic part of the Arctic. The research covers years 1971-2003 (ano-malies in SST taken from 1970-2002) due to the fact that the data have been not only accessible and reliable but also homogeneous with respect to climatological data of SST (CACSST data set (Reynolds and Roberts 1987, Reynolds 1988) and SST OI v.1. (Reynolds et al. 2002).
Źródło:
Problemy Klimatologii Polarnej; 2006, 16; 47-89
1234-0715
Pojawia się w:
Problemy Klimatologii Polarnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 31

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