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1

Characteristics of seasonal changes of the Baltic Sea extreme sea levels

Wolski Tomasz, Wiśniewski Bernard

Oceanologia

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2023

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Vol. 65 (1)

151--170

EN

This work analyses the monthly spatial distribution of extreme sea levels in the Baltic Sea as well as the relationship of these levels with the NAO and AO indicators. The research was based on hourly sea level data from the 45 tide gauge stations gathered in the years 1960 to 2020. The analysis shows that the duration of extreme sea levels tends to increase moving from along the line joining the open sea and the gulf end. This is associated with the narrowing of the gulf and the geomorphological and bathymetric configuration of the coastal zone. The duration of high and low sea levels in the Baltic Sea decreases from a maximum in January to a minimum in the months of May to August, then it increases again until the end of the year. This cycle corresponds well to the annual occurrence of storm surges, which are affected by the annual changes in atmospheric circulation. The impact of the variations of the circulation on extreme sea levels was confirmed by examining the relation between maximum, minimum and mean levels of the Baltic waters and the zone circulation indices NAO and AO for each month of the year and the seasons in the multiyear period 1960–2020. The results indicate that the strongest correlations exist between sea levels and NAO/AO in the winter months. There is a spatial differentiation of the correlation and its increase from the southwest to the northeast in Baltic Sea.

2

Drought Variability in Agadir's Region (Southern Morocco) – Recent and Future Trends

Amouch Said, Akhssas Ahmed

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 2

241--250

EN

The area of Agadir, which is situated on Morocco's southern Atlantic coast, is characterized by an arid climate, and has been strongly impacted by climate change. The purpose of this research is to assess observed and modeled drought variability in time, on the basis of rainfall time series for the periods 1973–2020, and 2022–2099 by use of SPI, short for Standardized Precipitation Index. Findings from the SPI analysis show that the years from 1981 to 1986 were the driest as per the instrumental record. Future SPI projections indicate that the area under study will face several prolonged drought and wet periods between 2022 and 2099. The longest drought will take place from 2090 to 2093. Analysis of the relationship between rainfall in Agadir and North Atlantic Oscillation (NAO), is also studied especially for the winter months. The results of the study will provide a basis for drought surveillance and hydrometeorological studies, in addition to initiating the desired managment of environment in this area.

3

Temperatura powietrza w Polsce podczas adwekcji z sektora zachodniego

Piotrowski Piotr

Przegląd Geofizyczny

|

2022

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Z. 3-4

119--133

PL

Częstość adwekcji mas powietrza z sektora zachodniego waha się na obszarze Polski w granicach od 44,7% w południowo-wschodniej części Polski do 52,4% w południowo-zachodniej części kraju. Cyrkulacja antycyklonalna z sektora zachodniego znacznie częściej obejmuje swym oddziaływaniem cały obszar Polski niż cyrkulacja cyklonalna, szczególnie jesienią i latem. Rozmieszczenie układów barycznych sterujących cyrkulacją cyklonalną i antycyklonalną z sektora zachodniego jest odmienne pod względem lokalizacji i stopnia rozbudowy przestrzennej układów niżowych i wyżowych w poszczególnych porach roku. Układ baryczny sterujący cyrkulacją antycyklonalną jest najbardziej rozbudowany jesienią i latem, natomiast cyrkulacją cyklonalną - zimą. Średnia temperatura powietrza o godz. 12:00 UTC na obszarze Polski podczas cyrkulacji antycyklonalnej jest wyższa we wszystkich miesiącach od średniej wartości temperatury powietrza z całego analizowanego okresu (1959-2021), natomiast w przypadku cyrkulacji cyklonalnej jest wyższa tylko od listopada do marca. Tendencje temperatury powietrza podczas cyrkulacji cyklonalnej i antycyklonalnej z sektora zachodniego we wszystkich porach roku są wzrostowe na całym obszarze Polski. Oscylacja Północnoatlantycka ma największy wpływ na temperaturę powietrza w Polsce o godz. 12:00 UTC w miesiącach zimowych, zarówno podczas cyrkulacji cyklonalnej, jak i antycyklonalnej z sektora zachodniego.

EN

The frequency of advection from west sector ranges from 44.7% in southeastern Poland to 52.4% in southwestern of country and has a significant impact on the conditions. Anticyclonic circulation from west sector much more often covers the entire area of Poland in comparison to cyclonic circulation, especially in autumn and summer. The localization of baric centers controlling the cyclonic and anticyclonic circulation from west sector in in the various seasons is different in terms of location and degree of spatial expansion in. Baric system controlling anticyclonic circulation is most spatially extended in autumn and summer, while during cyclonic circulation - in winter. Monthly mean of air temperature at 12:00 UTC in the Poland area during anticyclonic circulation is higher in all months than mean value over the entire period analyzed (1959-2021), while during cyclonic circulation monthly air temperature is higher only from November to March. The positive trends of air temperature during cyclonic and anticyclonic circulation occur in all seasons in the whole area of Poland. The highest positive trends of air temperature during the predominance of circulation from western sector over the Poland area are visible in spring and autumn during anticyclonic circulation. The North Atlantic Oscillation has the greatest impact on air temperature in Poland during the winter months, both during cyclonic and anticyclonic circulation from west sector.

4

Multi-annual variability of global solar radiation in the agricultural area of Lower Silesia (SW Poland) and its relationship with the North Atlantic Oscillation

Bryś Krystyna, Bryś Tadeusz

Meteorology Hydrology and Water Management. Research and Operational Applications

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2019

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Vol. 7, Iss. 2

13--25

EN

In this paper, the long-term variability of global solar radiation in the agricultural area of Lower Silesia is analyzed based on a 56-year long (1961-2016) measurement series recorded at the Agro- and Hydro-meteorological Wrocław-Swojec Observatory (SW Poland). Yearly and monthly global radiation sums with their extreme and mean values were compared with radiation data from Warsaw (Central Poland) and Potsdam (East Germany). The dynamics of variability between consecutive months, seasons and years was also taken into account. The conducted positive trends show a significant increase in the investigated global radiation sums for Lower Silesia and also for Central Poland and the eastern part of Germany. The trends are strongly related to long-term macro-circulation changes in the North Hemisphere, particularly with the phases and sub-phases of the North Atlantic Oscillation (NAO). The relations between the investigated values of global solar radiation and these macro-circulation patterns are very complicated and they very often have an asynchronous character. The first, juvenile stage of the NAO positive phase (the 1970s and 1980s), when annual sums of global solar radiation in Wrocław-Swojec reached only the average level of about 3700 MJ·m-2 and warm half-year about 2800 MJ·m-2 respectively, was cloudy and rainy. This period was distinctly different than the advanced stage of one (the 1990’s and later years) with bigger sunshine duration and smaller annual precipitation, when the adequate radiation sums amount to 3 900-4000 MJ·m-2 and 3 000-3 100 MJ·m-2 respectively.

5

Isotopic composition of precipitation in Poland: a 44-year record

Duliński Marek, Różański Kazimierz, Pierchała Anna, Gorczyca Zbigniew, Marzec Michał

Acta Geophysica

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2019

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Vol. 67, no. 6

1637--1648

EN

Isotopic composition of precipitation (2H/1H and 18O/16O isotope ratios, tritium content) is nowadays widely used in numerous applications of environmental isotopes—most notably in hydrology, climatology and biogeochemistry. Here we present a long record (44 years) of stable isotope composition and tritium content in monthly precipitation available for the Krakow station (southern Poland). Krakow is the only site in Poland for which long-term record of the isotopic composition of monthly precipitation is available. The tritium data are discussed here in the context of generally declining levels of bomb tritium in the global atmosphere and growing influence of technogenic emissions of this isotope. Two aspects of temporal variability of stable isotope composition of precipitation collected in Krakow are discussed here: (i) seasonality and (ii) interannual changes of δ18O and δ2H signal. Whereas the seasonality of stable isotope signal is generated mainly by seasonally varying the degree of rainout of air masses bringing moisture from the source regions (subtropical Atlantic Ocean) to the centre of the European continent, the North Atlantic Oscillation seems to govern interannual changes of δ18O and δ2H on the decadal timescale. Progressing warming of the local atmosphere, in the order of 1.8 °C in the past four decades, leaves its imprint in stable isotope signal measured in Krakow precipitation; the slope of isotope–temperature relationship is in the order of 0.50‰/°C for δ18O and 3.5‰/°C for δ2H.

6

An investigation of water level fluctuations in Polish lakes in various phases of the winter North Atlantic Oscillation

Wrzesiński D., Ptak M.

Geology, Geophysics and Environment

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2017

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Vol. 43, no. 2

151--163

EN

The North Atlantic Oscillation is a macroscale type of circulation determining climate and hydrological conditions in Europe. The paper presents water level fluctuations in 19 Polish lakes in various phases of NAO of the winter season in the years 1976-2010. Correlations of the winter NAO index with monthly, seasonal, maximum, and minimum water stages, and annual water level amplitudes in lakes were calculated. Approximately 20% of the performed tests showed statistical significance. Lakes were recorded where the correlations were significant in a major part of the year, as well as lakes showing no significant correlations in any month. Deviations of mean water stages in the positive and negative phase of NAO from mean water stages were calculated for each of the lakes. This permitted classifying the lakes into two groups by Ward’s method based on deviations of water stages in the positive and negative phase of NAODJFM from average values. This resulted in the designation of 4 and 5 typological classes of lakes, respectively. Deviations of water stages in lakes in various phases of NAODJFM from mean values were determined to even exceed 20 cm. The study results can find practical applications in reference to water retention. In view of the observed environmental changes, it is possible that the hydrotechnical infrastructure on lakes will have to be developed in the future. Such a situation will permit the precise control of water level fluctuations for the purpose of the optimal adaptation of lakes for economic purposes.

7

Long-Term Changes in Population Density of Nest-Box Breeding Great Tits and Blue Tits in Two Contrasting Habitats in Central Poland

Glądalski M., Wawrzyniak J., Bańbura M., Kaliński A., Markowski M., Skwarska J., Zieliński P., Bańbura J.

Polish Journal of Ecology

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2016

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Vol. 64, nr 3

399--408

EN

Urbanization affects the ecological and behavioral traits of various species of animals, including birds.We present results concerning long-term fluctuations in breeding densities of nest-box populations of the Blue Tit Cyanistes caeruleus and the Great Tit Parus major in two, structurally and floristically contrasting types of habitat (an urban parkland and a rich deciduous forest) located 10 km apart, in central Poland. This study was conducted in 1999–2012 in the parkland site and in 2002–2012 in the forest site. We found a strong correlation of year-to-year changes in breeding densities of Great Tits between the parkland site and the forest site and a lack of such a correlation in Blue Tits. Breeding densities of Great Tits were much higher in the parkland than in the forest area every year during the study period. Annual changes in breeding densities were not correlated between the species studied. The North Atlantic Oscillation Index (NAO-winter index) tended to influence the density dynamics of the two bird species in the forest area but not in the parkland area.

8

Zmienność termicznego charakteru okresów zimowych w Polsce i jej przyczyny

Marsz A. A., Styszyńska A.

Automatyka, Elektryka, Zakłócenia

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2015

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Vol. 6, Nr 4(22)

118-127

PL

Praca przybliża problematykę funkcjonowania fenomenu klimatycznego Oscylacji Północnego Atlantyku (Norh Atlantic Oscillation–NAO) oraz omawia jej wpływ na kształtowanie charakteru termicznego zim (grudzień–marzec) na obszarze Polski. Zmiana faz NAO z w przewadze ujemnych na w przewadze dodatnie, jaka nastąpiła w latach 1987-1989 spowodowała, że po roku 1989 obserwuje się w Polsce znaczne złagodzenie stopnia ostrości zim.

EN

The article raises the issue of the climate phenomenon of the North Atlantic Oscillation (NAO), and describes its influence on shaping the thermal character of winters (December-March) in Poland. The change of NAO phases from those predominantly negative into the predominantly positive, which took place within the years 1987-1989, caused the reduction in severity of winters after 1989 in Poland.

9

The atmospheric circulation patterns during dry periods in Lithuania

Rimkus E., Kažys J., Valiukas D., Stankunavičius G.

Oceanologia

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2014

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No. 56 (2)

223--239

EN

This paper reveals the atmospheric circulation patterns during dry periods in Lithuania.~The research covers the period from 1961 to 2010. Atmospheric circulation features were analysed using the Hess and Brezowski classification of macro-circulation forms, NAO and AO indices, a 500 hPa geopotential height field and the Tibaldi-Molteni blocking index. Different phases of the dry period (developing, persisting and attenuation) were evaluated individually. Also, the regional differences of dry period formation were investigated. In general dry periods are determined by a decrease in zonal and an increase in meridional circulation forms as well as the atmospheric blocking process over the Baltic region longitudinal belt 0-20 days prior to the start of the dry period. An especially strong shift from general circulation patterns are observed during the developing phase of a dry period. Drought persistence in the Baltic region is almost always predetermined by strong anticyclonic circulation. Most drought development stages are associated with negative NAO/AO phases.

10

NAO Soccer Robots Path Planning Based on Rough Mereology

Przytuła Ł.

Fundamenta Informaticae

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2014

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Vol. 131, nr 2

241--251

EN

Soccer game is a good playground for testing artificial intelligence of robots and methods for spatial reasoning in real conditions. Decision making and path planning are only two of many tasks performed while playing soccer. This paper describes an application of rough mereology introduced by Polkowski and Skowron (1994) for path planning in robotic soccer game. Our path planning method was based on mereological potential fields introduced by Polkowski and Ośmiałowski (2008) and Ośmiałowski (2009) but was redesigned due to conditions of dynamic soccer environment, so an entirely new method was developed.

11

Wpływ Oscylacji Północnoatlantyckiej (NAO) na wzrost temperatury powietrza nad Polską w warunkach zmiennych zasobów ciepła w Atlantyku Północnym

Marsz A.A.

Przegląd Geofizyczny

|

2013

|

Z. 3-4

127--143

PL

Przebieg temperatury nad Polską wykazuje bardzo silne związki ze wskaźnikami cyrkulacji atmosferycznej, w tym ze wskaźnikiem NAO. K.Kożuchowski (2011) zwraca uwagę, że wzrostowi temperatury w ostatnim dwudziestoleciu nie odpowiadają zmiany odpowiednich wskaźników cyrkulacji strefowej. Praca stanowi próbę wyjaśnienia rozbieżności między tempem wzrostu temperatury powietrza nad Polską a zmianami wartości wskaźnika NAO, wskazując na działanie dodatkowego czynnika, jakim jest systematyczny wzrost zasobów ciepła w wodach Atlantyku Północnego (oznaczenie Q). Roczna temperatura powietrza nad Polską w zasadniczej części jest regulowana przez zmienność temperatury zimy, wzrost temperatury zimy z kolei zależny od wzrostu wartości wskaźników cyrkulacji strefowej. Wskaźnik NAO w okresie zimowym wskazuje na intensywność napływu mas powietrza „wygrzanego” nad Atlantykiem Północnym. Wobec wzrostu zasobów ciepła (i SST) w Atlantyku Północnym (rys. 1, 2) w ostatnich latach mniej intensywna cyrkulacja strefowa zimą może przynosić nad Polskę powietrze o wyższej temperaturze. Weryfikacja tej hipotezy wykazuje, że uwzględnienie obok zmienności NAO zmienności Q (równanie (2), rys. 3) znacznie zmniejsza rozbieżności między obserwowaną temperaturą roczną nad Polską a temperaturą estymowaną wyłącznie ze wskaźnika NAO (równanie (1), rys. 3). W przypadku najsilniejszych wzrostów i spadków temperatury rocznej nad Polską wymagana jest koincydencja znaków i wartości wskaźnika NAO i Q. Wysokim wartościom zasobów ciepła w wodach Atlantyku Północnego w latach 1930. nieodpowiadał ekwiwalentny wzrost temperatury powietrza nad Polską, gdyż charakter występującej wtedy cyrkulacji atmosferycznej (ujemne w przewadze wartości wskaźnika NAO; rys. 4) nie doprowadzał do napływu powietrza atlantyckiego nad Polskę.

EN

The course of temperature over Poland has a very strong relationship with indicators of atmos¬pheric circulation, including the NAO index. K. Kożuchowski (2011) points out that the temperature rise in the last twenty years does not correspond to changes in relevant indicators of zonal circulation. The work is an attempt to explain the discrepancy between the rate of increase in air temperature over Poland and changes in values of NAO index, pointing to the influence of an additional factor, which is a systematic increase in heat resources in the waters of the North Atlantic (marked Q). Annual air temperature over Poland is mainly controlled by the temperature changes in winter. Winter temperature, in turn, depends on the intensity of zonal circulation. A positive NAO index in winter indicates the intensity of the inflow of air masses “warmed” over the North Atlantic. With rising heat resources (and SST) in the North Atlantic (Fig. 1, 2) in recent years, less intense zonal circulation in winter can bring air of higher temperature over Poland. Verification of this hypothesis shows that adding variability of Q (equation (2), Fig. 3) to variation of NAO significantly reduces the discrepancy between the observed annual temperature over Polish in relation to the temperature estimated only with the NAO index (equation (1), Fig. 3) .The influence of Q on annual temperature over Poland is independent of the zonal circulation, but for the occurrence of the strongest increases and decreases the temperature the coincidence of signs and changes in the NAO index and Q is required. High values of heat resources in the waters of the North Atlantic in the 30-ties of the twentieth century did not match an equivalent increase in air temperature over Poland as the nature of the atmospheric circulation observed at that time (predominantly negative NAO index values, Fig. 4) did not result in the inflow of air from the Atlantic over Poland.

12

Klasyfikacja górnych pól wiatru w okresach dodatniej i ujemnej fazy oscylacji północnoatlantyckiej

Degirmendzić J.

Przegląd Geofizyczny

|

2012

|

Z. 2

157-169

PL

Celem pracy jest wyróżnienie najczęstszych typów górnej cyrkulacji związanych z silnie dodatnią i silnie ujemną fazą NAO oraz określenie stref górnej dywergencji i rozkładów SLP związanych z typami cyrkulacji górnotroposferycznej. Wykorzystano następujące dane: składowe wiatru z Reanaliz NCEP-NCAR (0, 12 UTC, 300 hPa, 1958-2007), dobową serię NAO, pola dywergencji (300 hPa) i ciśnienia (SLP) z Reanaliz ERA-40. Analiza dotyczy sezonu zimowego. Pola wiatru podzielono na dwie próby: pierwszą, związaną z silną dodatnią fazą NAO, drugą, odpowiadającą silnej ujemnej fazie NAO. Oddzielne procedury klasyfikacji zastosowano względem obu prób. Wykorzystano zmodyfikowaną metodę Lunda - współczynnik Pearsona zastąpiono współczynnikiem korelacji wektorowej Crosby’ego. Pola dywergencji i SLP uśredniono w klasach cyrkulacji. Analizę ograniczono do 9 najliczniejszych klas cyrkulacji związanych z NAO+ + i 9 klas związanych z NAO- _. Wyróżnione klasy grupują ok. 66% wszystkich pól występujących w fazie NAO+ + i ok. 48% wszystkich pól występujących podczas NAO- -. Ten wynik wskazuje na dość dużą liczbę pól, które tworzą mało liczne grupy, które nie zostały uwzględnione w badaniu. Biorąc pod uwagę położenie struktur w polu wiatru, które generują silną dywergencję, wyróżnione klasy pogrupowano w kategorie, w obrębie, których te same cechy pola wiatru wpływają na dynamikę Wyżu Azorskiego i Niżu Islandzkiego. Scharakteryzowano 3 kategorie procesów synoptycznych, które intensyfikują dodatnią fazę NAO oraz 2 kategorie procesów charakterystycznych dla silnej ujemnej fazy NAO.

EN

The aim of this paper is to distinguish the most frequent upper circulation types associated with strong negative and positive NAO phase and to delimit zones of upper divergence and SLP fields associated with selected types. The following datasets are utilised: wind records from the NCEPNCAR Reanalysis (0, 12 UTC, 300 hPa, 19582007), daily NAO record, divergence (300 hPa) and pressure (SLP) fields from ERA40. The analysis is confined to winter season. Wind fields were divided into two samples: the first related to strong positive NAO phase, the second corresponding to strong negative NAO phase. Separate classification procedures were applied to both samples. Modified Lund classification method was used - Pearson coefficient was replaced with Crosby vector correlation coefficient. The divergence and SLP deviations fields were averaged within circulation classes. The analysis is restricted to nine largest wind classes associated with NAO+ + and the other nine classes associated with NAO- _. Analysed classes group ~66% of all fields related to NAO+ + and ~48% of all fields occurring during NAO- -. This result indicates a fairly large number of fields that form small classes, which were not included in the study. Having considered the position of the wind field features which generate strong divergence, selected types were grouped into categories within which the same wind features affect the dynamics of the Azores high and the Iceland low. Three categories of synoptic processes, which intensify NAO and two categories of synoptic processes characteristic for NAO- - were described.

13

Rozkład przestrzenny kwadrantów jet streak w górnej troposferze w okresach dodatniej oraz ujemnej fazy NAO

Degirmendzić J.

Przegląd Geofizyczny

|

2011

|

Z. 3-4

149-170

PL

Celem analizy jest określenie związków pomiędzy rozmieszczeniem dywergentnych i konwergentnych kwadrantów jet streak w górnej troposferze a fazą Oscylacji Północnoatlantyckiej. W procedurach obliczeniowych wykorzystano pola wiatru z powierzchni 300 hPa nad sektorem euroatlantyc- kim, z rozdzielczością 4 X dobę, obejmujące okres 1958-2007 oraz serie dobowych wartości indeksu NAO. W terminowych polach wiatru zlokalizowano układy jet streak oraz określono pozycje ich kwadrantów (LF, RR, LR i RF). Następnie zliczono wystąpienia poszczególnych sektorów jet streak w kolistych gridach osobno w okresie dodatniej i ujemnej fazy NAO. Przestrzenne rozkłady częstości kwadrantów oraz rozkłady różnic częstości kwadratów dywergentnych i konwergentnych stanowią podstawą niniejszej analizy. Rezultaty analizy wskazują, Se w dodatniej fazie NAO nad północną częścią badanego akwenu Atlantyku przewaSają dywergentne sektory jet streak nad konwergentnymi, a nad południowym regionem zaznacza się dominacja kwadrantów konwergentnych. Taki rozkład kwadrantów jet streak sprzyja utrwalaniu pola ciśnienia związanego z fazą NAO + . W ujemnej fazie oscylacji w obu regionach Atlantyku (Islandii i Azorów) występuje nieznaczna przewaga dywergentnych sektorów jet streak. Ta przewaga nie różni się wyraźnie między regionami, co sprzyja utrwalaniu słabego gradientu ciśnienia między Islandią a Azorami. Również proces zmiany fazy NAO wydaje się być stymulowany przez zmianę cyrkulacji w górnej troposferze - podczas transformacji NAO- do NAO+ obserwuje się wzrost przewagi kwadrantów dywergentnych nad regionem północnym oraz początkowy spadek przewagi dywergentnych sektorów i późniejszy wzrost dominacji konwergentnych sektorów nad południowym regionem badanego akwenu Atlantyku.

EN

The radiolarian fauna from deep-water settings in the Umbria- Marche and the Outer Carpathian basins of the Western Tethys is used for biostratigraphic purpose and interpretation of environmental changes during the late Cenomanian through the Early Turonian time interval. The frequency of 184 recognized species, thirteen of them newly described, has been processed and analyzed. Three radiolarian biozones and one subzone are distinguished based on radiolarian datum events, correlated with the chronostratigraphic scale through the ?13C curve. The whole radiolarian set has been subdivided into six super groups, including 25 groups related to specific water masses. The assembled species represented various feeding preferences and ecological strategies. An increase of radiolarian total number in the sediments related to the Bonarelli Level (BL) displays a positive correlation with an increase of phosphorus (P) content, and with a significant decrease in radiolarian diversity. Most of radiolarian species avoided levels with high P content, in contrast, some species as H. barbui and C. conara increased significantly in number of specimens. Diversified radiolarian assemblages appeared at levels, directly preceded by a notable P increase, marking a period when the water system was saturated in relation to nitrogen. The radiolarian abundance in the sediments was strongly related to their preservation during sinking in the water column and at the water/sediment interface, increasing significantly at levels, marked by high pellet production. Thus, pelletization played an important role in the transport of radiolarian skeletons and their further preservation, irrespective to conditions of radiolarians growth. Radiolarians experienced and responded to environmental changes during the 1.8 Ma around the Bonarelli Interval (BI). The Cenomanian-Turonian press extinction event – a period of unquestionable eutrophication represented by the BI, did not result in great radiolarian extinction and turnovers. The radiolarian radiation preceded the BI by over 330 ka. The extinction, directly connected with the OAE2 started ca. 240 ka before the end of the organic-rich sedimentation, coinciding with the onset of enhanced diatom frustules deposition, recorded in the siliceous part of the BI. Since this period, a step-wise radiolarian extinction continued through the Early Turonian. Many of the radiolarian species previously considered as terminating during the BI, in fact outlived up to “post-Bonarelli” times, having their last occurrence after the BI or even in the Early Turonian. In the case of the radiolarian fauna, the Bonarelli period caused the disappearance of many Lazarus taxa, which returned in almost their initial state during 940 ka after the BI. The current radiolarian study sheds light on the biological effects of anoxic events, indicating the role of the mesopelagic zone and oceanic circulation in nutrient exchange, which modulates and controls the OAE2. The mesopelagic zone played an important role in P sequestration and was responsible for the release of the most of P, leading to enhanced eutrophication of water column.

14

Zmiany klimatyczne w Arktyce Kanadyjskiej w ostatnim ćwierćwieczu XX i na początku XXI wieku

Zblewski S., Marsz A. A.

Problemy Klimatologii Polarnej

|

2010

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nr 20

45-62

PL

Praca omawia zmiany temperatury powietrza na obszarze Subarktyki i Arktyki Kanadyjskiej oraz otaczających je akwenów oraz podejmuje próbę ustalenia roli cyrkulacji atmosferycznej w kształtowaniu tych zmian. Analizie poddano temperaturę powietrza, temperaturę powierzchni morza oraz koncentrację lodów morskich w latach 1982-2009. Stwierdzono występowanie dodatnich trendów temperatury rocznej powietrza na całym obszarze. Wyniki badań wskazują, że zmianami temperatury powietrza, temperatury powierzchni morza i koncentracji lodów morskich w rejonie wschodniej części Arktyki Kanadyjskiej (Zatoka Baffina, Ziemia Baffina, Wyspa Devon, Półwysep Bothia i Basen Foxe'a) steruje NAO. Kierunki zmian wymienionych elementów są odwrotne do fazy NAO (ujemna faza NAO – wzrost temperatury powietrza i morza, spadek koncentracji lodów, dodatnia faza NAO – odwrotnie). Oddziaływanie NAO na temperaturę powietrza jest najsilniejsze w okresie zimowym, oddziaływanie zimowego NAO na temperaturę powierzchni morza i koncentrację lodów jest asynchro-niczne (najsilniejsze latem) i realizuje się poprzez działanie ogniwa pośredniego, jakim jest grubość lodów morskich. Na zachód od linii Cambridge Bay – Baker Lake głównym czynnikiem sterującym zmianami temperatury powietrza jest układ telekoneksyjny PNA. Jego działanie jest najsilniejsze w końcu jesieni i początku zimy, najwyraźniej działanie PNA zaznacza się na obszarze Kanadyjskiej Subarktyki i słabnie w kierunku N i NE. Zmienność PNA wywiera niewielki wpływ (tylko w sierpniu) na koncentrację lodów i temperaturę wody Morza Beauforta. Dodatnim fazom PNA odpowiada wzrost temperatury powietrza. Wystąpienie wzrostu rocznej temperatury powietrza na całym obszarze Arktyki i Subarktyki Kanadyjskiej wymaga wystąpienia w tym samym roku ujemnej fazy NAO i dodatniej fazy PNA. Jeśli w danym roku wystąpią jednoimienne fazy obu oscylacji, stosownie do znaków obu oscylacji na części badanego obszaru zaznaczy się występowanie dodatnich, a na części – ujemnych anomalii temperatury powietrza. Ponieważ w badanym okresie w zmienności NAO zaznacza się trend ujemny, w przebiegu PNA słaby trend dodatni, można uważać, że obserwowany wzrost temperatury powietrza nad obszarem Arktyki i Subarktyki Kanadyjskiej w dużej części jest rezultatem długookresowych zmian warunków cyrkulacyjnych.

EN

This work describes changes in air temperature in the region of Subarctic and Canadian Arctic and in the sea area adjacent to them and is an attempt to define the influence of atmospheric circulation on these changes. The analysis covered the air temperature, sea surface temperature and sea ice concentration. The analyzed period lasted from 1982-2009. Positive trends in air temperature were noted over the whole area. The results of the research indicate that NAO is responsible for the changes in the air temperature, sea surface temperature and the concentration of sea ice in the region of the eastern part of the Canadian Arctic (the Baffin Bay, Baffin Island, Devon Island, the Bothnia Peninsula and Foxe Basin). The direction of changes is opposite to the phase of NAO (negative phase of NAO – increase in sea and air temperatures, decrease in ice concentration, positive phase of NAO – just the other way round). The strongest impact of NAO on air temperature is observed in winter. The influence of winter NAO on sea surface temperature and on ice concentration is asynchronous (the strongest in summer) and employs action of an indirect factor, i.e. the thickness of ice. West of Cambridge Bay – Baker Lake line the main factor responsible for the changes in air temperature is teleconnection pattern of PNA (Pacific-North American). Its impact is the strongest at the end of autumn and the beginning of winter (October-December). Most clearly the influence of PNA is marked in the region of the Canadian Subarctic (southern and central party of Northwest Territories), its influence becomes weaker northwards and north-eastward. Changeability of PNA has little influence on sea surface temperature of the Beaufort Sea and on its ice concentration. Positive phases of PNA are associated with the increase in air temperature. The observed increase in annual air temperature over the entire area of the Canadian Arctic and Subarctic must be accompanied by negative phase of NAO in the same year and by positive phase of PNA. If in a given year there are the same phases of both oscillations, following the signs of these oscillations, positive anomalies in air temperature are observed in the Subarctic region and in the Canadian Arctic and negative anomalies in some parts. As in the analyzed period of NAO variability a negative trend is marked and in PNA a weak positive trend is noted, it may be assumed that the observed increase in air temperature over the Subarctic region and in the Canadian Arctic results, to a great extent, from long term changes in conditions of circulation.

15

Zmiany temperatury powierzchni Morza Barentsa w latach 1951-2006

Zblewski S.

Problemy Klimatologii Polarnej

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2007

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nr 17

61-70

PL

Praca charakteryzuje zmiany temperatury powierzchni Morza Barentsa (TPM) zachodzące w okresie 1951–2006. Stwierdzono występowanie słabych, dodatnich i istotnych statystycznie trendów TPM w gridach leżących poza obszarem bezpośredniego oddziaływania ciepłych prądów morskich. Odnotowano słaby i nierównomiernie rozłożony w przestrzeni wzrost temperatury powierzchni morza – silniejszy we wschodniej części Morza Barentsa. W badanym okresie (1951–2006) na obserwowaną zmienność rocznej TPM znacznie silniejszy wpływ wywierają procesy oceaniczne niż zmienność zimowej cyrkulacji atmosferycznej.

EN

The aim of this work was to analyse monthly and annual values of sea surface temperatures of the Barents Sea in the years covering the period from 1951 up to 2006 averaged to chosen grids 2x2° (Fig. 1).The analysis showed that in the course of SST a clearly marked period (1976–1988) of significant decrease in annual values of water temperature was noted, with the minimum observed in 1980 (Fig. 2). This phenomenon is connected with Great Salinity Anomaly.The research showed that the general decrease in annual SST takes place towards north-east and at the same time, following the same direction, the increase in amplitude of inter-annual changes can be observed (Fig. 3). ‘The warm sources of the North Cape Current and West Spitsbergen Current moving away and the transfer of heat from the ocean to the atmosphere are the cause of this situation. This significant drop in annual sea surface temperature in the NE part of the Barents Sea is also influenced by flows of cold and fresh Surface Arctic Waters from the Arctic and Kara seas. There were also great differences observed in the course of annual SST in the western and eastern parts of the examined sea area. (Fig.4). In the eastern part rapid falls in water temperature can be noted by even 0.7°C from year to year. They result from the sea ice spreading and Surface Arctic Waters from the Kara Sea and from the north region of the Barents Sea which cut off the flow of heat from the deeper parts of the sea towards the surface and to the atmosphere.In the examined period weak positive trends in the annual sea surface temperature were observed and they are statistically significant in almost all grids (Tab.1). The strongest trends were noted in the east part of the examined sea area. Positive and statistically significant trends of the monthly SST are observed in summer and autumn in grids located farthest NE.The analysis showed that the influence of winter atmospheric circulation on the temperature of the sea surface is weak or rather moderate (Tab. 2) and that the observed changeability in annual sea surface temperature of the Barents Sea is mainly controlled by oceanic processes.

16

O "arktycznych" i "atlantyckich" mechanizmach sterujących zmiennością temperatury powietrza na obszarze Europy i północo-zachodniej Azji

Marsz A. A., Styszyńska A.

Problemy Klimatologii Polarnej

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2006

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nr 16

47-89

PL

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.

EN

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).

17

Natural versus anthropic causes in variations of sand export from river basins: an example from the Guadiana River Mouth (Southwestern Iberia)

Dias J. M. A., Gonzales R., Ferreira Ó.

Polish Geological Institute Special Papers

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2004

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Vol. 11

95-102

EN

Flood events in many river basins with highly variable discharge values remove accumulated sediments from the riverbed and estuaries. These sediments are exported to the shelf and the adjacent coastlines. Data for rainfall and river discharge for the Guadiana River basin in southwestern Iberia show a strong link with North Atlantic Oscillation (NAO) index patterns. A negative NAO index usually results in more rainfall, and subsequent flooding in the river basin during winter months. During the second half of the 20th century, the flow regime of the Guadiana River and its tributaries have been increasingly constrained by the construction of dams. The consequences were a reduction of coarse-grained sediment export from the upper river basin to the estuary, and a reduction in the number and type of floods.