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1

Wpływ bezwładności cieplnej budynku na wykres obciążeń

Szymański Władysław, Babiarz Bożena

Ciepłownictwo, Ogrzewnictwo, Wentylacja

|

2022

|

T. 53, nr 7-8

8--14

PL

Specyficzną cechą systemów ciepłowniczych jest fakt, że obciążenie cieplne systemu charakteryzuje się dużą zmiennością w ciągu roku. Do analizy tej zmienności mającej wielorakie zastosowanie wykorzystywany jest wykres obciążeń cieplnych. Podstawą sporządzania wykresu obciążeń jest zmienność temperatury powietrza zewnętrznego charakterystyczna dla lokalizacji obiektu, dla którego sporządzany jest wykres. W metodologii sporządzania wykresu zakłada się w każdej chwili proporcjonalność strat ciepła na ogrzewanie i wentylację do różnicy temperatury powietrza wewnętrznego i powietrza zewnętrznego, pomijając bezwładność cieplną przegród budowlanych. W przedstawionym artykule przeprowadzono analizę wpływu bezwładności cieplnej przegród na zmienność obciążeń cieplnych w roku, porównując ją z dotychczas stosowanym wykresem obciążeń. Do wyznaczenia bezwładności cieplnej wykorzystano opracowaną wcześniej metodologię obliczeń. W efekcie wykazano znaczną różnicę pomiędzy teoretycznym i rzeczywistym przebiegiem wykresu obciążeń cieplnych. Wyniki potwierdzono przykładami zmian zużycia ciepła w rzeczywistych obiektach budowlanych.

EN

A specific feature of district heating systems is the fact that the heat load of the system is highly variable through the year. The heat load diagram is used to analyze this variability with multiple applications. The basis for the preparation of the load diagram is the variability of the outside air temperature, characteristic for the location of the object for which the diagram is prepared. The methodology of drawing up the diagram assumes that the heat loss for heating and ventilation is proportional to the temperature difference between internal and external air at any time, ignoring the thermal inertia of building partitions. In the presented article, an analysis of the influence of thermal inertia of partitions on the thermal loads’ variability during a year was carried out, in comparison with the load diagram used so far. The calculation methodology developed earlier was used to determine the thermal inertia. As a result, a significant difference was demonstrated between the theoretical and real course of the thermal load diagram. The results were confirmed by examples of changes in heat consumption in real buildings.

2

Variability of shoulder girdle temperature in the initial phase of the snatch in weightlifting

Kuniszyk-Jóźkowiak Wiesława, Jaszczuk Janusz, Czaplicki Adam, Szyszka Paulina

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 3

143--148

EN

The identification of activation, synchronization and work of individual muscles in the subsequent stages of lifting weights is interesting for researchers and trainers. Unfortunately, the existing methods of research do not provide such possibilities. Such information could be gathered from infrared measurements as they are non-invasive and can be carried out without the direct involvement of the weightlifter. The purpose of the study was to analyse temperature changes in the shoulder girdle in the first phase of the snatch in weightlifting. Methods: The study involved 11 weightlifters who competed in two weight categories, 94 and 105 kg, during the World University Championships in 2018. The performance of the snatch was recorded using a thermographic camera in three consecutive attempts. We analysed the temperature changes in the left and right shoulder girdles in the two initial stages of the snatch. Statistical analysis of empirical data was performed using linear mixed effects models. Results: Statistically significant temperature increases were found from the moment of gripping the barbell to the moment it was pulled. These effects were different in individual weightlifters, but did not depend on the attempt or the side of the body. Conclusions: Temperature increases in the initial phase of the snatch are most likely the result of activating successive motor units in order to perform the effort needed to pull the barbell and cause it to accelerate. The results obtained confirm that thermography is an effective method of monitoring muscle activity in weightlifting, which may be useful for coaches and athletes.

3

Zmienność przestrzenna wybranych parametrów ziemskiego pola termicznego na obszarze polskich Karpat i zapadliska przedkarpackiego (streszczenie)

Kudrewicz R.

Wiadomości Naftowe i Gazownicze

|

2018

|

R. 21, Nr 11 (241)

s. 4--7

PL

Celami pracy były: konstrukcja trójwymiarowego modelu parametrycznego opisującego zmienność przestrzenną temperatury, gradientu geotermicznego i stopnia geotermicznego na obszarze Karpat i zapadliska przedkarpackiego; sprawdzenie hipotezy o nieregularnych zmianach temperatury i gradientu w trzech wymiarach oraz przedstawienie skonstruowanego modelu w sposób pozwalający na jego interpretację i użycie w przyszłych badaniach naukowych.

4

Changes in electromyographic signals and skin temperature during standardised effort in volleyball players

Kuniszyk-Jóźkowiak W., Jaszczuk J., Czaplicki A.

Acta of Bioengineering and Biomechanics

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2018

|

Vol. 20, no. 3

115--122

EN

The state of athletes’ muscles is not constant, but it differs depending on the stage of sports training, which is associated with different degrees of muscle fatigue. There is thus a need to find a non-invasive and simple method to assess muscle fatigue. The aim of the study was to determine the relationship between muscle fatigue due to physical effort and changes in skin temperature, measured using a thermographic camera. Methods: The study involved 12 volleyball players. The participants were to maintain 70% of peak torque in the joint for as long as possible. We measured peak torque and the time of maintaining 70% of its value (tlim) as well as continuously recording skin temperature and electromyographic (EMG) signals in the region of the belly of the rectus femoris. The measurements were taken twice: before and after a series of squats. Results: The study found that tlim decreased when isometric contraction was performed after physical effort. Pre- and post-exercise skin temperature did not differ significantly, however, the increase rates of temperature and the root mean square (RMS) of the EMG signals grew significantly. In most of the players, skin temperature also correlated with the RMS, median frequency (MDF), and mean frequency (MF) of the EMG signals. Conclusions: Measuring the time of maintaining submaximal torque during isometric contraction and the slope coefficient for the increase in temperature recorded using a thermographic camera can be a simple, cost-effective, and non-invasive method of assessing fatigue and efficiency decreases in the muscles in volleyball players.

5

Mechanistic-empirical asphalt pavement design considering the effect of seasonal temperature variations

Haponiuk B., Zbiciak A.

Archives of Civil Engineering

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2016

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Vol. 62, nr 4/I

35--50

EN

The paper analyses the influence of seasonal temperature variations on fatigue strength of flexible and semi-rigid pavement structures chosen for KR4 traffic flow category. The durability of pavement determined assuming a yearly equivalent temperature of 10˚C and assuming season-dependent equivalent temperatures was compared. Durability of pavement was determined with the use of Asphalt Institute Method and French Method. Finite Element Method was applied in order to obtain the strain and stress states by the means of ANSYS Mechanical software. Obtained results indicate a considerable drop in pavement durability if seasonal temperature variations are considered (up to 64% for flexible pavements and up to 80% for semi-rigid pavements). Durability obtained by the French Method presents lower dependence on the analysed aspect.

PL

Celem pracy jest analiza wpływu sezonowych zmian temperatury na trwałość podatnych i półsztywnych nawierzchni drogowych. W artykule porównano trwałość nawierzchni wyznaczoną przy założeniu całorocznej temperatury ekwiwalentnej 10˚C oraz przy założeniu różnych temperatur ekwiwalentnych odniesionych do trzech pór roku: wiosny/jesieni, lata oraz zimy. Do analizy wybrano siedem typów nawierzchni odpowiednich do obciążenia ruchem kategorii KR4 według dwóch edycji „Katalogu typowych konstrukcji nawierzchni podatnych i półsztywnych” (z 1997 roku i z 2014 roku). Wszystkie nawierzchnie zostały zamodelowane jako konstrukcje składające się z warstw o określonych parametrach. Każdą z warstw zdefiniowano poprzez jej grubość, moduł Younga oraz liczbę Poissona v. Przygotowano trzy modele w odniesieniu do każdego z typów nawierzchni (jeden dla każdej pory roku), by uwzględnić zależność parametrów E oraz v od temperatury. Stan naprężeń i odkształceń poszczególnych nawierzchni uzyskano w programie ANSYS Mechanical poprzez analizę wykorzystującą metodę elementów skończonych (MES).

6

Influence of traffic flow variability of heavy vehicles and temperature on pavement fatigue life

Spławińska M., Zieliński P., Burnos P.

Roads and Bridges - Drogi i Mosty

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2015

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Vol. 14, no. 2

117--132

PL

W pracy przedstawiono wpływ zmienności temperatury i natężeń ruchu pojazdów ciężkich na trwałość zmęczeniową podatnych nawierzchni drogowych (nawierzchnie z podbudową z kruszywa niezwiązanego oraz z betonu asfaltowego. Podziału terytorium Polski na grupy jednorodne ruchowo i temperaturowo dokonano przy łącznym wykorzystaniu metod ilościowych (analiza skupień oraz jakościowych (przynależność geograficzno-funkcjonalna. Podstawą podziału był kształt profili zmienności temperatury oraz natężeń ruchu w kolejnych miesiącach w roku i w następujących po sobie sezonach. Po określeniu jednorodnych grup wyznaczono dla nich reprezentatywne profile zmienności natężeń ruchu oraz temperatury, które wykorzystano do obliczenia trwałości zmęczeniowej konstrukcji nawierzchni. Trwałość zmęczeniową wyznaczono wykorzystując kryterium zmęczeniowe warstw asfaltowych według Instytutu Asfaltowego. Obliczenia stanu naprężeń i odkształceń w nawierzchni przeprowadzono z wykorzystaniem programu BISAR. Uzyskane wyniki pozwoliły na porównanie oraz wskazanie różnic w otrzymanych trwałościach nawierzchni w zależności od przyjętych wartości temperatury ekwiwalentnej.

EN

The paper presents the effect of temperature variability and traffic flow variability on fatigue life of flexible road pavements (pavements with the subgrade made of unbound aggregates and asphalt concrete'. The division of the territory of Poland for the homogeneous groups in terms of movement and temperature was made at the use of quantitative methods (cluster analysis' and qualitative methods (geographical and functional affiliation'. The basis for the division was the shape of the profiles of temperature and traffic flow variability in subsequent months of the year and in successive seasons. After determining homogeneous groups, representative profiles of traffic flows and temperature variability were established, which were used to calculate the fatigue life of pavement structure. Fatigue life was determined using the criterion of fatigue of asphalt layers according to the Asphalt Institute. The calculations of stress and strain in the pavement were carried out using the program BISAR. The results have permitted comparison and identification of differences in pavement durability obtained depending on the values of equivalent temperatures.

7

Doświadczenia z betonowania fundamentu cylindrycznej wieży ujęcia wody z zastosowaniem betonu podwodnego

Kańka S.

Inżynieria i Budownictwo

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2011

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R. 67, nr 10

519-522

PL

Przedstawiono problemy techniczne, jakie rozwiązano podczas betonowania fundamentu blokowego posadowionego na dnie retencyjnego zbiornika wodnego, na głębokości około 15 m poniżej normalnego poziomu piętrzenia. Omówiono proces doświadczalnej weryfikacji przyjętej technologii układania betonu oraz wyniki badań samozagęszczalnej mieszanki betonowej przystosowanej do układania pod wodą. Analizowano zmienność temperatury w wybranych miejscach twardniejącego pod wodą betonu fundamentu.

EN

The paper deals with technical problems that occurred during placing the concrete in the block shape foundation. The foundation is settled at the bottom of water reservoir at a depth of about 15 m below the normal level of impoundments. A process of experimental verification of applied technology of laying concrete on the assumed depth is presented, as well as test results for self-compacting mix adapted to placing under the water. In addition, during concrete underwater hardening, temperature distributions of selected sections of foundation are presented.

8

Zmienność temperatury u spodu sezonowej pokrywy śnieżnej w strefie sporadycznego występowania wieloletniej zmarzliny w Tatrach

Gądek B., Leszkiewicz J.

Landform Analysis

|

2008

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Vol. 9

115--119

9

Wpływ zmian klimatycznych na temperaturę podpowierzchniową Ziemi

Szewczyk J.

Przegląd Geologiczny

|

2005

|

Vol. 53, nr 1

77--86

EN

Climate changes are accompanied by temperature changes on the Earth’s surface. Over the past cen-tury the Earth’s surface temperature has been increasing. Is the observed warming simply a natural climatic fluctuation or is it tied to industrialization? A key to the understanding of the climate changeis to understand past climate fluctuations. Temperature changes at the Earth’s surface spread into the subsurface by heat conduction, and manifest at a later time by perturbations in the background of temperature field. Boreholes of several hundreds or thousands of meters depth contain a record of responses to ground surface temperature history over thousands or even of hundreds of thousands years, back to the last glaciation. Geothermal data provide an important supplement to traditional proxy records of surface temperature change. The paper presents results of our investigations of this problem starting from daily temperature fluctuations to the temperature of Weichselian glaciation.

10

Zmienność temperatury w procesie obróbki cyklicznie nieciągłej i jej skutki

Harasymowicz J.

Archiwum Technologii Maszyn i Automatyzacji

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2004

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Vol. 24, nr 2

11-18

PL

W artykule omówiono przyczyny występowania w obróbce cyklicznie zmiennej rys i pęknięć krawędzi ostrzy narzędzi z materiałów twardych. Autor proponuje uzupełnić hipotezę Opitza swoją hipotezą opartą na zaburzeniach termosprężystych.

EN

The reasons of scratches and cracks occurring on the cutting edge of tools made of hard materials during serial non-continuous cutting are described in the publication. Author tries to complete the H. Optiz's hypothesis by his own hypothesis basing on the thermo elastic disturbances.

11

Zmienność temperatury powietrza w północnej Polsce

Banaszkiewicz B., Panfil M.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2003

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Vol. 12, No. 1

91--97

EN

The paper presents analysis results of variability of air temperature in northem Poland. The comparison monthly mean values of air temperature of the 1951-1990 period with adequate values of 1881-1930 and 1931-1960 revealed that values of the 1951-1990 years are higher on the all investigated area in June and also generally in period from October to December (Figure 1). Monthly mean air temperature in the years of 1951-1990 revealed often inereasing tendency in winter months, March and May; how ever descending trend of air temperature occurred generally from June to September (Figure 2). The observed changes of mean values of monthly air temperature in Koszalin are in prevailing cases representative for all area of northem Poland. The spectral (Fourier) analysis of mean annual air temperature in Koszalin of the period 1851-1990 was done also. The data were filtered (it was used the 4235H filter), the linear trend and means values were removed from the series before the analysis. The periodogram values was computed using Hamming window (5). Four dominant cycles found in Fourier analysis were used to predict the temperature for the 1851-2030 period (Figure 4).

12

Zmienność temperatury gruntu w Hornsundzie w okresie 1979-1999

Miętus M., Filipiak J.

Przegląd Geofizyczny

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2001

|

Z. 4

323-337

EN

In the paper the analysis of the variability of the soil temperature on the Polish polar station in Hornsund, situated in southwestern part of Spitsbergen, has been presented. The soil temperature data from the depths 5, 10, 20, 50 and 100 cm cover the period 1979-1999. In the annual cycle of the soil temperature variability the 8-month period, while the soil is frozen, can be observed. Positive values of temperature in the whole-analyzed profile occur only during the 3-month-lasting period from July to September. In the cool season the highest temperatures are recorded in the deeper layer, additionally the greatest values of the standard deviation in the considered depths are met. In the warm season the temperature decreases with the depth. During the spring and autumn, when the isothermal conditions in the soil profile are observed, the reversion of the temperature profile is recorded. The most thermally active layer is the upper one - deep to 20 cm. Reaction of deeper layers to the thermal processes above the ground and in the upper layers is weaker and time-delayed. The greatest differences of temperature between the lowest layer and the upper ones are recorded during the polar night. Air temperature significantly influences the variability of the soil temperature. The relationships between the soil temperature and the other meteorological elements i.e. sunshine duration, cloudiness, persistence of snow cover and its depth are not confirmed by the high values of correlation coefficients. The annual variability of the soil temperature can be approximated with the first harmonic. Below the depth of 184 cm maximum soil temperature do not exceed 0°C. In the whole examined profile the positive long-term tendencies of the temperature are observed, but the statistically significant trend (+0.126°C/year) occurs only on depth 10 cm.

13

Trendy i okresowość zmian temperatury powietrza w Polsce w drugiej połowie XX wieku

Fortuniak K., Kożuchowski K., Żmudzka E.

Przegląd Geofizyczny

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2001

|

Z. 4

283-303

EN

The aim of the paper is to evaluate the main patterns of temperature variations in Poland in the second half of the XX-th century. It concerns mainly the answers to 3 questions: 1) at what degree are the averaged values of temperature changed in the period 1951-2000, 2) how are the cyclic components of the observed changes, 3) are there any empirical proofs of the realisation of climate scenarios in which the warming is predicted? The spatially averaged time series of air temperature registered at 51 meteorological stations have been analysed. Several statistical methods have been used both for trends and periodicity identification: analysis of linear regression, the method of rank trend of Mann-Kendall, cumulative deviations, the J. Boryczka method of regression sinusoids, the spectral analysis after Blackmann and Tukey (1958) and singular spectral analysis (SSA) after Vautard (1992). The rise of annual mean temperature in Poland in 50-year period has been estimated as 0.9 centigrade. An increase in temperature intensified significantly after 1980. This warming occurred especially in the spring, in January, February, July and August. The temperature values in spring in 1980. and 1990. were higher then ones estimated in climate scenario (HadCM2 GS) for the middle of XXI-th century. The oscillation of the period of ca 8-year in the annual and December-March monthly temperatures has been found. It explains 31-42 percent of the observed temperature variations. On the other hand - the linear rising trend explains only 9 percent of variation. The climate model HadCM2 GS predicts the rise of annual temperature in Poland in 2050. by 1.4 centigrade from the 1981-2000 mean. However, the coincidence of the simulation with the observed temperature variation in the past is rather weak; differences concern especially the seasonal distribution of temperature changes.

14

Rekonstrukcja zmian temperatury powierzchni gruntu w Polsce w ostatnim 500-leciu na podstawie profili geotermicznych

Majorowicz J., Šafanda J., Przybylak R., Wójcik G.

Przegląd Geofizyczny

|

2001

|

Z. 4

305-321

EN

Reconstruction of the ground surface temperature history in Poland was derived from the in-version of the temperature profiles with depth in over 20 wells. Temperature histories for the period 1500 A.D. till 1977 A.D. agree well with instrumental record of the surface air temperature available for the last two centuries. We are observing large warming since early 19th century of the magnitude of 0.6-0.9°C preceded by a colder climate since 1500 A.D. interrupted by a warmer one with a local maximum in the 1700 A.D. The climatic reconstructions based on the deepest wells (> 470 m depth) show very god correlation among groups of wells. The statistical correlation of the reconstructed histories (from the well temperature data) with the instrumental record (air temperature) from the homogeneous Warsaw series is very high. Statistical correlation coefficient as high as 0.9 is seen for some groups of wells. Geothermal data and their inversion is the only direct physical method to determine the value of warming/cooling events in the past. This is done without the need of calibration based on the correlation with the present air surface temperature record as needed for the proxy reconstructions (tree rings etc

15

Ocieplenie w Polsce : skala i rozkład sezonowy zmian temperatury powietrza w drugiej połowie XX wieku

Kożuchowski K., Żmudzka E.

Przegląd Geofizyczny

|

2001

|

Z. 1-2

81-90

EN

In the report the results of statistical analysis of the mean monthly and annual air temperature series in Poland in the period 1951-2000 have been presented. The calculated means have been based on data from 51 weather stations located at the altitude below 1000 m above the sea level. The mean of the year 2000 was a maximum value of all since 1951 and probably since the end of 18th century. The analysis of order of appearance of rising values using the method of rank trend of Mann--Kendall, has proved an essential positive trend of average annual, March and May temperature values in the period of 1951-2000. This effect has been confirmed by a simple linear trend analysis. The rise of annual mean in 50-year period has been estimated as 0,9 centigrade. The highest May, August and annual average values of temperatures in the period of 1981-2000 proved to be higher than in the period of 1951-2000. In the long-term time series of 1951-2000 a shorter 7-8 year period oscillations around average has been found. In the 80s. and 90s. the significant rise in the mean annual air temperature occurred. Some reasons of climate warming have been discussed including intensification of zonal circulation and rise of insolation in the end of studied 50-year period. The coincidence of climate warming in Poland with global temperature rise has been also stressed

16

Wpływ warunków cyrkulacyjnych na zmienność temperatury wody u południowych wybrzeży Zatoki Pomorskiej

Kowalewska-Kalkowska H.

Zeszyty Naukowe. Marine Sciences / Uniwersytet Szczeciński

|

2000

|

Nr 6

19-38

EN

The work presents the results of studies on the influence of circulation conditions on variability of water temperature at the southern toast of the Pomeranian Bay. In order to resolve the problem mean daily water temperature values as measured at Międzyzdroje and Gozdowice as well as mean air temperature values at Świnoujście were analysed under different circulation conditions to obtain statistical relations between them. Simple and multiple regression analyses were performed. The period 1971-1980 u taken into the examination. In the ten year period 1971-1980 the air circulation coming from the east sector was prevailing from February to July and coming from the west sector was prevailing from August to January. For these two periods the highly statistically significant coefficients of correlation between water temperature as measured at Międzyzdroje a Gozdowice as well as air temperature at Świnoujście made possible to describe inshore water temperature using the equations of simple and multiple regression. As the highly statistically significant coefficients of correlation were also obtained for the periods different types of air circulation so for all these periods the equations of simple a multiple regression were also written. The multiple regression equations show that the influence of water temperature the Odra River on inshore water temperature was stronger than the influence of air temperature, especially during the periods of air circulation coming from south-west north-west directions. The effect of air temperature was the strongest when the circulation from north-east was recorded. In that case the influence of water temperature of the Odra was decreased.

17

Wieloletnia zmienność temperatury powietrza w Szczecinie (1836-1995)

Wiśniewski B., Medyna P., Wolski T.

Zeszyty Naukowe. Marine Sciences / Uniwersytet Szczeciński

|

2000

|

Nr 6

7-18

EN

The presumption of this publication is description of the air temperature in Szczecin in the period 1836-1995. On the basis of 160-year series, the change of climatic epoch in 19th and 20th century was described and perennial cycles in air temperature were defined. For this purpose, various statistical methods were used. Analysis indicates, that seasonally and yearly changes of air temperature in research periods in Szczecin are quite strong variable: -The perennial variability in air temperature of cold seasons is considerably bigger than warm seasons. -On the whole length of 160-year series there is lack of extremely warm periods. The most frequently occurring are the moderate years and seasons. -The quasi 7-year cycle of air temperature was confirmed.

18

Współczesne trendy zmian temperatury powietrza w Polsce

Smukała P.

Zeszyty Naukowe. Marine Sciences / Uniwersytet Szczeciński

|

1999

|

Nr 5

73-93

EN

Statistical methods used in the work have confirmed the results of study on the observed climate of Poland. According to the analysis which was carried on the topic distinguishing fluctuations of temperature changes in July and winter occurred. At the end of 80 ties winter warning because of its resistance take the features of an important climate anomaly. The cumulative deviations described by O.A Drozdov and A.S. Grigorieva have proved the existence of significant tendency in winter months. The growing tendency of the last decade is characteristic for the whole winter season. Hot summers of the last decade have disturbed the tendency of falling temperatures of the summer in Poland. The significant tendency of fluctuating air temperatures which were observed on the basis of cumulative deviations in June end July only. There haven't been observed any significant temperature fluctuations in other summer months as well as in the whole summer season.

19

Krótkookresowa zmienność temperatury powietrza w Polsce

Żmudzka E.

Przegląd Geofizyczny

|

1999

|

Z. 3

115-130

EN

The aim of the paper is to determine (on the base of the data of the air temperature from 58 meteorological stations): -the periodical changes (from 1 to 30 years) of the air temperature over Poland within a period of 1951-1990 in the climatological seasons and in the year, -identification of causes of the short-term oscillations of the air temperature - pointed out the synchronous cycles of the air temperature, atmospheric circulation and solar activity. The Boryczka's method of 'regression sinusoids' has been used. The spectral analysis shows that over Poland a few cyclical components with meaningful ranges have been observed. These are cycles: 2-, 3-, 6-, 8-, 10-, 14-16-years. Their presence in all chronological progressions and synchronous (the same periods and phases), particularly 8-years cycle, imply thesis, that periodicity is typical feature of temperature field over Poland. The synchronous (concurrence of periods and coincidence of extremums) of 8- and 11-years component of air temperature changes with the solar activity can testify that solar conditions determine these changes. The researches suppose that periodical changes of the air temperature over Poland are conditioned by the corresponding cycles of atmospheric circulation.

20

Zmienność parametrów termicznych w Arktyce Norweskiej w okresie 1951-1990

Przybylak R.

Problemy Klimatologii Polarnej

|

1999

|

nr 9

23--36

EN

In the paper, changes in mea n annual intraseasonal (within season) and interannual (between years) temperature variability have been analysed over the Norwegian Arctic for the period 1951 to 1990. The daily maximum (TMAX) r mean (TSR), minimum (TMIN) temperatures and the diurnal temperature range (AMP) for the Jan Mayen and Hopen stations were examined. The temperature variability parameters and the method of computations was the same as in Plummer (1996), except the computation method of the long-term daily mean values, which here were obtained by averaging daily data from the period 1951-1990. Plummer have received these series by performing a Fourier analysis of their monthly mea n and interpolating from their respective average annual cycles. In the Norwegian Arctic, similarly as for Australia (Plummer 1996), trends in intraseasonal temperature variability were mixed and in all cases not statistically significant (Figs 1-8). These results are in good agreement with the observed lack of warming in the studied area over the period 1951-1990 (Przybylak 1996, 1997). Most sensitive to high-frequency temperature variability, of the four thermic parameters, is TMAX. Plummer (1996) also found similar results for Australia. The range of changes in intraseasonal variability and their values decreases when the time-scale of averaging intervals increases. Small, not statistically significant, increases in interannual variability for all thermic parameters were observed in the studied area (Fig. g). The greatest interannual variability in both analysed stations shows TMIN and the lowest AMP. In Australia Plummer found TMAX as the most sensitive to this kind of variability.