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EN
The geological field trip of the Student Science Association of Geologists at the University of Wroclaw took place in September of 2018. The main goal of a 17-day and a 2850 km long trip around Iceland was to study the field geology and to gain the knowledge on active extensional tectonics, volcanism and magmatic processes in a complex geotectonic setting of the Atlatnic Mid-ocean Ridge combined with the mantle plume, as exemplified by Iceland. The group visited several dozen spectacular geosites in the active volcanic systems of Askja, Hekla, Krafla, Laki, Torfajökull, few geothermal fields across the country along with many sites of general geological and touristic interest, like waterfalls, fiords, glacial lagoons and others. This fascinating field study tour greatly deepened the geological experience of participants, highlighting the diversity and complexity of natural tectonic and volcanic phenomena.
PL
Górna część zlewni Buchtarmy znajduje się w obrębie najwyższych partii Wysokiego Ałtaju. Buchtarma, prawy dopływ Irtyszu, charakteryzuje się reżimem glacjalnym kształtowanym głównie przez liczne lodowce masywu Biełuchy (4506 m n.p.m.). W ciągu ostatnich stu lat obserwuje się wyraźne ocieplenie tej części Azji Centralnej, co wpływa m.in. na szybkie tempo recesji lodowców. Celem prowadzonych badań jest przedstawienie współczesnej dynamiki wybranych procesów rzeźbotwórczych zachodzących w górnej części zlewni Buchtarmy. W trakcie prac terenowych wykonano kartowanie geomorfologiczne oraz pobrano materiał w celu wykonania laboratoryjnych analiz sedymentologicznych i dendrochronologicznych. Do badań szczegółowych wyznaczono dwa obszary: dolinę Buchtarmy pomiędzy miejscowościami Berel a Dżambuł oraz górny odcinek doliny Białej Bereli. Dna dolin oraz przyległe zbocza pokrywają poligenetyczne osady pylasto-piaszczyste. Ich występowanie związane jest z plejstoceńskimi zmianami klimatycznymi na obszarze Wschodniego Kazachstanu, które przejawiały się wzmożoną działalnością synchronicznie przebiegających procesów eolicznych i stokowych. Pylasta pokrywa stanowi tutaj stropową część plejstoceńskiej sekwencji glacigenicznej. Poniżej powszechnie występują osady fluwioglacjalne. Są one w wielu miejscach porozcinane przez młode formy erozyjne, powstałe w rezultacie kolektywizacji rolnictwa w drugiej połowieXXw. Współczesne procesy morfogenetyczne w najwyższej części Ałtaju są generowane głównie przez intensywne topnienie lodowców. Analiza dendrochronologiczna i geomorfologiczna form glacjalnych i fluwioglacjalnych w masywie Biełuchy potwierdza bardzo szybką deglacjację tego obszaru w ciągu ostatnich stu lat. Świadczą o tym świeże moreny czołowe oraz liczne, włożone terasy fluwioglacjalne. Materiał mineralny transportowany przez rzeki glacjalne w postaci zawiesiny jest akumulowany w górnych odcinkach dolin, a następnie może podlegać deflacji i depozycji eolicznej. Rezultaty rekonesansowych badań w Ałtaju Wysokim wskazują na duże zróżnicowanie procesów rzeźbotwórczych i form. Wynikają one z krótkiego czasu reakcji na zmiany wysokogórskich geosystemów Azji Centralnej na współczesne zmiany klimatyczne, potęgowane lokalnie ingerencją człowieka.
EN
The upper part of the Bukhtarma River basin is located in the High Altai Mountains. The river, right tributary ofthe Irtysh River, has glacial regime shaped mainly by the glaciers of the Belukha massif (4506 m a.s.l.). Scientific research show that the glaciers in the Altai Mountains are melting rapidly. This process is connected with significant climate warming, which is observed over this part of the Central Asia.The aim of the research is to present contemporary dynamics of selected geomorphic processes in the upper part of the Bukhtarma catchment. Two research areas were selected for detailed study: 1) the Bukhtarma River valley between Dzambul and Berel villages, and 2) the upper part of the White Berel River catchment. Geomorphological mapping and mineral and plant samples collection were carried out during field research. Laboratory works included sedimentological and dendrochronological analysis. Common occurrence of silty covers on these areas is connected with Pleistocene climate changes. These features are related to Aeolian and fluvial activity in high mountain environment. In the vicinity of villages the young gully forms are also observed. The present development of erosion processes is linked to collectivization during the Soviet Union time. The dendrochronologicaland geomorphological analysis of glacial and fluvioglacial land forms confirmed rapid glaciers retreat in the Belukha massif. Mineral sediment transported in suspension in the glacial rivers is deposited in the upper parts of the valleys. This fluvial silty material can be winnowed, transported and redeposited in the lower parts of the main Altai Mountains valleys.
PL
Trzecia z cyklu publikacji, których celem jest przedstawienie prostych metod obliczania różnych typów płytowych wymienników ciepła typu ciecz-ciecz, parowników, skraplaczy oraz wymienników krzyżowo-prądowych typu gaz-gaz. Prezentowane sposoby prowadzenia obliczeń zobrazowane są przykładami obliczeniowymi. Druga z publikacji tego cyklu ukazała się w „TCHK” w numerze 6-7/2010 (s.246) i była poświęcona sposobom prowadzenia obliczeń cieplnych wymienników płytowych, pełniących rolę parowaczy i skraplaczy oraz wymiennika krzyżowo-prądowego typu gaz-gaz, stosowanego w układach do odzysku ciepła. Podane zostały w niej procedury wyznaczania pola powierzchni tych wymienników dla założonej ich wydajności cieplnej. Zaproponowane metody obliczeniowe zweryfikowano obliczeniami wykonanymi programem komputerowym firmy Sondex. Trzecia część cyklu poświęcona jest obliczeniom cieplnym i przepływowym wymienników zasilanych zawiesiną lodową. I w tym przypadku podano przykładowe obliczenia cieplne wymiennika płytowego zasilanego taką zawiesiną
EN
This is third part of papers dealing with simple methods of heat transfer calculations in liquid-liquid plate heat exchangers plate evaporators, plate condensers gas-gas cross flow plate exchangers. Calculation examples areincluded. The second part has been published TCHiK 6-7/2010and dealt with calculationmethods for plate evaporators, condensers and gas-to-gas heat exchangers used in heat recovery systems. methods of heat transfer area calculation for demanded heat capacity have been described and postively verified with the use of computer code for heat exchangers selection by Sondex. The third part of papers deals with calculation methods for heat exchangers working with slurry ice. Here calculation example are included as well.
PL
W pracy omówione są zmiany powierzchni lodów morskich zachodzące współcześnie w Antarktyce i Arktyce oraz problemy żeglugi na akwenach Arktyki. Zwraca się uwagę, że powierzchnia lodów morskich w Antarktyce powoli wzrasta, a powierzchnia lodów w Arktyce bardzo gwałtownie maleje. Autorzy są zdania, że w ciągu najbliższych lat nastąpi stopniowe ochłodzenie Arktyki i wzrost powierzchni lodów, związane z przejściem AMO do fazy zstępującej. Żegluga w Arktyce dla statków bez klasy lodowej lub z niską klasą lodową nie będzie bezpieczna nawet latem, a trasą z Europy do Cieśniny Beringa przez biegun – niemożliwa. Wydłużenie sezonu żeglugowego na wodach arktycznych możliwe jest, w perspektywie najbliższych kilkunastu lat, jedynie poprzez budowę statków o odpowiednio wysokich parametrach technicznych, specjalnie przystosowanych do żeglugi w lodach.
EN
This work deals with changes in the sea ice cover of the Antarctica and Arctic observed nowadays and with the problems connected with navigation in the Arctic. It has been pointed out that sea ice cover in the Antarctic is increasing slowly whereas sea ice cover in tine Arctic is decreasing rapidly. The main reason for such decrease is attributed to greater inflow of warm Atlantic waters connected with positive phase of AMO (Atlantic Multidecadal Oscillation). Nowadays very optimistic opinions are being spread regarding the possibilities of the development of navigation in the Arctic. These opinions are connected with anticipated disappearance of summer sea ice cover in the years 2013-2015 and disappearance of sea ice cover even in winter a few or a dozen years later. The authors think that within the next few years a gradual cooling of the Arctic will be observed. It will be accompanied by the increase in the sea ice cover connected with the change of AMO into descending phase. Navigation in the Arctic for vessels without ice class or with low ice class will not be safe even in summer and the route from Europe to the Bering Strait via the pole will not be possible at all. The prolonged navigation season in the Arctic waters is possible in the nearest dozen of years only for vessels of adequately high technical parameters, specially built for navigation in ice.
5
Content available remote Monitoring of tidewater glaciers on Svalbard using ASTER images
EN
The purpose of this study is to describe different methods of using ASTER images (Advanced Spaceborne Thermal Emission and Refl ection Radiometer) for monitoring of tidewater glaciers on Svalbard, an archipelago in the northern part of Europe. Monitoring of tidewater glaciers is of special importance, especially considering the present climate changes. Changes in the geometry of glacier tongues, negative mass balance and front retreat have been noticed within last twenty years. The author proposes procedures of examining tidewater glaciers characteristics, generation of digital elevation model (DEM) from satellite stereo pairs and automatic delineation of glacier areas in satellite imagery (mapping of glaciers boundaries). The most important morphometric features of all tidewater glaciers derived from satellite images are: glacier area, length of centreline, glacier slope and aspect, extent of crevassed zone close to the active calving front, length of the ice cliff and front position changes. Image texture parameters were also applied to the identification of crevassed areas and to the separation of ice fl oat from glaciers. The surface velocity fi elds of glacier termini were derived from ASTER image pairs using feature tracking methods. The paper aims at the continuation of the work of Hagen et al. (1993) focusing on updating different information. The list of proposed methods of satellite data processing is recommended for assessing changes in Svalbard glacier areas in the future, during the next International Polar Year.
PL
Przedmiotem niniejszej pracy jest zaprezentowanie różnych metod wykorzystania obrazów satelitarnych ASTER (Advanced Spaceborne Thermal Emission and Relfection Radiometer) w monitorowaniu lodowców Archipelagu Svalbard Drzewpołożonego w północnej części Europy. Monitoring lodowców uchodzących do morza jest istotny w świetle współczesnych zmian klimatu. Od dwudziestu lat notuje się ciągły ubytek powierzchni tych lodowców wskutek topnienia lodowców i recesji klifów. Pozyskanie teledetekcyjnych danych o lodowcach uchodzących do morza obejmowało następujące etapy: analiza ilościowa lodowców współcześnie uchodzących do morza, generowanie numerycznego modelu terenu, automatyczne wyznaczanie obszarów zlodowaconych na obrazach, wyznaczenie basenów glacjalnych (generowanie granic lodowców) oraz wyznaczenie parametrów morfometrycznych takich jak: długość i powierzchnia lodowca, wielkość strefy uszczelinionej czoła lodowca, wystawa, nachylenie, długość klifu czy wielkość recesji. Omówiono także możliwość wykorzystania analizy teksturalnej dla wyznaczania obszarów uszczelinionych na lodowcach oraz do wydzielenia lodu pływającego na powierzchni morza. Wypracowano metody pomiaru rocznych prędkości lodowców na parach obrazów ASTER z wykorzystaniem metody feature tracking. Zebrane dane są uaktualnieniem inwentarza lodowców Svalbardu wydanego w 1993 roku (Hagen et al., 1993). Wypracowane metody przetwarzania danych teledetekcyjnych oraz zebrane dane stanowią podstawę do wyznaczania zmian charakteru zlodowacenia Svalbardu podczas kolejnego Międzynarodowego Roku Polarnego.
EN
Global climate change occurs naturally and periodically and is often attributed to continental drift, variations in the earth's axis and orbit, variations in solar energy output and the frequency of volcanic activity. However, over the past few decades human activities have significantly altered the atmospheric composition, causing a climate change not previously experienced (IPCC, 2001). The first report of the Intergovernmental Panel on Climate Change (IPCC) assessed projections which suggested global average temperature increases between 0.15 and 0.3°C per decade from 1990 to 2005. The mountain glaciers and snow cover on average have declined in both hemispheres and the maximum areal extent of seasonally frozen ground has decreased about by 7% in the Northern Hemisphere since 1900, with decreases in spring of up to 15% (IPCC, 2007). Kyrgyzstan is one of the extensively glaciated regions in the world . A variety of available sources were used in this study in order to detect changes to the Petrova Glacier, which is one of the largest glaciers of the Ak-Shyjrak glacierized Massif in Central Tien-Shan (Kyrgyzstan). Glacier mass change is difficult to measure from the multispectral remote sensing data of Landsat, therefore glacier shrinkage was described as a loss of glacier area. The objective of this study is to characterize changes across a period of more than 60 years, from 1943 to 2006. The total area of glacier in previous years was calculated from the available cartographical data and its recent state from Landsat satellite images. A new policy of free availability of the Landsat data series allows for wider opportunities for monitoring glaciers in remote areas. The extraction of relevant parameters of glaciers from SRTM data also plays a significant role, especially in mountain areas
PL
Lodowce gór Tien-Szan są odnawialnym źródłem świeżej wody, z której korzystają miliony ludzi w Centralnej Azji. Cofanie się lodowca może być jednym z czynników globalnych zmian klimatycznych. Zgodnie z ostatnim raportem IPCC (2007) całkowity wzrost temperatury od lat 1850-1899 do lat 2001-2005 wyniósł 0.76°C. Oszacowano, że wzrost średniej temperatury o 1°C w stosunku do roku 1850 może spowodować zmniejszenie się powierzchni lodowców górskich aż o 40% i o ponad 50% zmniejszenie ich objętości. W niniejszej pracy podjęto próbę oszacowania wpływu globalnego ocieplenia na lodowiec Pietrowej, jeden z największych lodowców masywu Ak-Szijrak (Kirgistan), z wykorzystaniem analizy multispektralnych danych satelitarnych oraz dostępnych danych kartograficznych. Celem badania jest scharakteryzowanie rozmieszczenia przestrzennego Lodowca Pietrowej i jego zmian w okresie ponad 60 lat, od 1943 do 2006 roku. Zmiana lodowca bądź masy śniegowej jest trudna do zmierzenia przy użyciu multispektralnych danych satelitarnych Landsat, zatem zmniejszanie się lodowca zostało opisane jako ubytek powierzchni lodowca, który jest funkcją odległości przebytej przez cofający się brzeg lodowca. Do określenia całkowitej powierzchni lodowców zastosowano techniki przetwarzanie multispektralnych obrazów Landsat TM.
PL
Przeanalizowano wielkość oraz przestrzenną zmienność akumulacji śniegu na lodowcach rejonu Kaffioyry w sezonie letnim 2006 roku. Pokrywa śnieżna na lodowcach Waldemara i Ireny występowała do połowy sierpnia, a w najwyższych partiach pól akumulacyjnych i u podnóża stoków górskich przez cały sezon ablacyjny. W przypadku Lodowca Elizy pod koniec sezonu śnieg zajmował wyraźnie większą powierzchnię. Na podstawie szczegółowych pomiarów dokonano oceny zmienności akumulacji z wysokością nad poziomem morza oraz zróżnicowanie gęstości śniegu. Pozwoliło to określić ekwiwalent wodny pokrywy śnieżnej. Stwierdzono, że znajomość miąższości i przestrzennego zróżnicowania pokrywy śnieżnej w okresie letnim oraz stref glacjalnych na lodowcu stanowi ważny element w badaniach i ocenie tempa ablacji lodowcowej.
EN
Size and spatial variability of snow accumulation on the Kaffiřyra glaciers were analysed in the summer of 2006. The values of accumulation changeability at the growing altitude and the diversity of accumulation density were based on detailed measurements. This enabled to estimate the thickness of the snow cover in water equivalent (w.e.). In the summer season of 2006 average snow accumulation on the Waldemar Glacier was 9.3 cm of water equivalent. On average, it changed from 24.1 cm w.e. at the beginning of the summer season to 1.1 cm w.e. in August. Mean snow accumulation on the Irene Glacier amounted to 7.3 cm e.w.; on average it changed from 15.6 to 1.0 cm w.e. Mean snow accumulation on the Elise Glacier was 25.8 cm w.e. and it changed from 36.1 July to 12.0 cm w.e. at the end of August. The largest diversity of snow accumulation at the growing altitude was recorded on the Elise Glacier. From both the Waldemar Glacier and Irene Glacier the snow cover disappeared quickly. As a result, at the end of the ablation season snow was only visible in the upper parts of the accumulation zones of those glaciers and at the foot of the mountain slopes. The Elise Glacier had a longer-lasting snow cover on large areas which survived until the end of the season. This was not only the outcome of the weather conditions but, predominantly, larger altitude diversity between the snout of this glacier and its accumulative pars as well. In higher parts of the glacier a larger snow loss in time is recorded. Mean snow thickness in the summer season is nearly twice higher than during the spring season with the snow cover. There is a correlation between the snow cover thickness and the altitude. However, with time and the diminishing snow cover this interrelation is less distinct. Another distinct interrelation exists between spatial diversity of snow accumulation and the size and spatial diversity of snow ablation. Melting of the snow cover during the summer season favours the creation of different glacial zones which influence the intensity of summer ablation. The knowledge of the thickness and spatial variability of the snow cover during the summer season, as well as the glacial zones poses an important element of the study and assessment of the rate of glacial ablation.
PL
Celem badan prezentowanych w niniejszej pracy była ocena dokładności NMT generowanego z zobrazowań satelitarnych ASTER w obszarach polarnych oraz możliwości wykorzystania go do ortorektyfikacji obrazów. W ramach badan wygenerowano NMT ASTER w trzech różnych rozdzielczościach 30, 60 i 120 metrów. W celu zbadania wpływu ukształtowania terenu na dokładność generowanego NMT, obszar badan został podzielony na cztery rodzaje pól testowych: wody, lodowce, obszary lądu o niewielkim nachyleniu oraz obszary górskie. Ocenę dokładności produktu NMT ASTER wykonano w oparciu o referencyjny NMT Foto wykonany na podstawie zdjęć lotniczych 1:50 000. Oba modele porównano ze sobą generując dla każdej z rozdzielczości obrazy różnic. W badaniach przyjęto, że NMT o błędzie mniejszym ni_ 100 m może być wykorzystany do ortorektyfikacji, ponieważ generuje on błąd w poziomie wielkości ok. jednego piksela (15 m). W żadnym miejscu na obszarach płaskich i na obszarze wody błąd NMT nie przekraczał wartości 100 m. Błędy grube wystąpiły na 9.5 % powierzchni obszarów górskich dla NMT ASTER 30, ale już tylko na 6 % powierzchni dla oczka siatki 60 i 120 m. Natomiast odsetek obszarów występowania błędów grubych na lodowcach był znikomy – 2.5 % dla NMT o rozdzielczości 30 m i tylko 1.5 % dla rozdzielczości 120 m.
EN
Evaluation of accuracy of ASTER DEM generation in polar regions and its applicability to orto-rectification was investigated. In the first phase of the research, ASTER DEMs of three various resolution values (30, 60 and 120 m) were generated. In order to assess the influence of area type on the DEM accuracy, the research territory was divided into four test areas: water, glaciers, lands with small slope and mountainous regions. ASTER DEM accuracy was evaluated on the basis of Photo DEM made from aerial photos scaled 1:50 000. Both products were compared by generating differential images for every resolution. In the research, an assumption was made that ASTER DEM with an error below 100 m can be used for orto-rectification, as maximum height error of 95 m translates into a horizontal displacement of approximately 14 m (accuracy of about 1 pixel). In the case of waters and flat lands, there was any error larger than 100 m. Gross errors occurred within 9.5 % of mountainous areas for ASTER DEM 30m and 6 % for ASTER DEM 60m and 120m. However, the percentage of gross errors for glaciers amounted to 2.5 % for ASTER DEM 30m and just 1.5 % for ASTER DEM 120m.
PL
W pracy przedstawiono wyniki badań zimowej akumulacji śniegu na trzech lodowcach regionu Kaffioyry, NW Spitsbergen. Stwierdzono zróżnicowanie przestrzenne i z wysokością nad poziomem morza miąższości pokrywy śnieżnej. Na podstawie wykonanych pomiarów struktury i uziarnienia pokrywy śnieżnej stwierdzono jej duże zróżnicowanie w różnych częściach lodowców. Zimowa akumulacja śniegu na lodowcu Waldemara wyniosła 43.4 cm e.w., w przypadku lodowca Ireny całkowita zimowa akumulacja śniegu była zbliżona i wyniosła 40.2 cm e.w. Z kolei akumulacja lodowca Elizy wyniosła 58.5 cm e.w.
EN
The analysed glaciers are located in the northern part of the Oscar II Land, northwestern Spits-bergen. Measurements were done in May 2005. The main goal of investigations was to determine water resources in snow and to estimate input in the mass balance equation for the glaciers. The measurements comprised and referred to thickness, density, water equivalent and snow structure. An aluminium probe was used to measuring of depth in a snow cover. The measurements were taken three times at every site. Snow pits were dug if a snow layer could not be passed through. Measurement sites were located on the map in scale 1:1000 and with a use of GPS. Basic measure-ment sites were the ablation poles installed during a preceding summer.
10
Content available remote Lodowce w odwrocie
EN
The work has been intended to determine relations between short-term changes of the snow cover thickness on the glacier and meteorological parameters recorded on the glacier and in the glacier vicinity. Short-term relations are regarded as connections between variations of the snow depth on the glacier and the course of meteorological factors in a scale of up to 24-hours. Detailed snow and meteorological measurements were carried out on the equilibrium line (364 m a.s.l.) of Aavatsmark Glacier (NW Spitsber-gen) in two periods: 11 - 30th April 2001 and 12th April - 5th May 2002. The thickness of snow was investigated with the use of Sonic Ranging Sensor SR50 Campbell Scientific Ltd. Meteorological data comes from an automatic weather station located on the glacier?s surface and from meteorological sites on Kaffioyra and Ny-Alesund. All measurements were taken in 10-minute step. Short-term changes of the snow thickness on glaciers in winter seasons are influenced by the precipitation and snow transport. The wind power determines the scale of snow transport. In consequence, the increase of wind speed causes higher intensity of changes of the snow level. The intensity of changes of the snow depth within the range from 0 to 8ˇ10-6 m/s is connected with the average wind speed of 4 m/s and changes intensity over 17ˇ10-6 m/s accompanied the average wind speed 8.7 m/s. The appearance of precipitation in daily or longer time-scale causes the increase of snow thickness and the weakness of relations between changes of the snow depth and the wind speed. In a time-scale of several hours the snow supply leads to the increase of both intensity and amplitude of snow level changes. Significant increase of the intensity and amplitude of changes of snow depth took place over the average wind speed 5 m/s in days without precipitation and over 8 m/s in days with snowfall. Short-term changes of the snow thickness are constrained by availability of an unconsolidated, easy-to-transport material. The major part of that material comes from precipitation. As a result short-term changes of the snow depth are more noticeable during days with precipitation. A thin crust layer on the snow surface has been formed as a result of friction of air masses and snow particles. In emergence of the positive tempe-rature and good radiation conditions in the upper snow layer ice crust can be formed. After stabilization of the snow cover even powerful wind gust can?t start transporting the material and short-term changes of the snow thickness are limited.
EN
When documentary work was carried out on the Vestre and Austre Torellbreen, an extremely strong recession of ice cliffs of both glaciers was observed. In order to obtain more detailed picture of the observed retreat over the period 2001, 2002 and 2003, GPS measures of the ice cliffs location and the location of glacier fronts were taken. Then the obtained results were compared to previous maps (Fig. 1). The ice cliff of the AustreTorellreen retreated by 3190m from the year 1936 till 2003. The fastest recession of this ice cliff was noted over the last three years; the average rate of the retreat reached 166m/year. The ice cliff of the Vestre Torellreen retreated by 3163m from the year 1936. The maximum speed of the recession of this cliff was also noted in the last three years and reached 68m/year. The sides of both glaciers which are located on the shore tend to have lower rate of recession, i.e. 40-50m/year. The retreat of glaciers is mainly attributed to the observed global warming but in the case of the Vestre and Austre Torellbreen which empty for the sea, it is the increase in sea surface temperature that plays the main role. The annual temperature of the coastal waters between Bellsund and Hornsund, that is in waters adjacent to both glaciers increased by 2°C over the period from 1996 and 2002. Such significant warming in the sea water together with the prolonged period without sea ice cover result in advanced undercutting of ice cliffs by waves and an increased role of calving in the negative mass balance of glaciers. The retreat of the ice cliff of the Vestre Torellbreen, which is partially sheltered against waves by a recently formed spur, has a rate half lower.
EN
The sea ice cover of the Greenland and Barents seas is characterised by great seasonal and interannual changeability which has influence on radiation and heat balance of that region. This changeability is directly observed in changes in atmospheric circulation and further noted in changes in meteorological elements (mainly in air temperature, cloudiness, precipitation and wind). Changes in weather conditions determine both the value of losses of glacier masses in a given balance year and the value of ice masses accumulation. This article tries to find the answer to a question if and to what extent the variability of the extent and rate of the Barents and Greenland seas ice formation is directly reflected in changeability of glaciers masses balance in the region of Spitsbergen. This research was based on the mass balance of two small glaciers located in the region of Kongsfjord, i.e. Austre Brogger and Midre Lovén. The mean monthly values of sea ice cover observed in the Greenland and Barents seas in the period 1972-1994 were used in this research (the values calculated on the basis of 1-week values of these seas ice cover taken from NCDC - Asheville). The values of winter, summer and net balances of the said glaciers were drawn from article by Lefauconnier et al. (1999). In addition, the correlation was examined between the balance Austre Brogger and Midre Lovén glaciers and the changeability of atmospheric circulation described by Niedźwiedź ?circulation types? (2001). The research made use of standard statistical analysis (correlation and regression analysis). Statistically significant correlations have been noted between the values of winter balances of both examined glaciers and the size of ice cover of the Barents and Greenland seas at the initial stage of its formation - in November (r ~ -0.55÷0.64, adj. R2 ~ 0.30÷0.35). The result of analysis of multiple regression indicated that the strongest correlation with ice cover of the Greenland Sea occurs in September, whereas in the Barents Sea in December (R ~ 0.70÷0.83). Changes in sea ice cover observed in that time explain 44% and 65% of changeability in winter balance of Austre Brogger and Midre Lovén glaciers, respectively. These results suggest that the process of heat transfer from the ocean to the atmosphere may by very intensive when the sea is merely covered with ice in the areas on the way of main directions of air mass advection. This will provide favourable condition for clear domination of sea air masses resulting in the increase in air temperature (Styszyńska 2000) and precipitation in the region of NW Spitsbergen. The summer balance of the examined glaciers is influenced by the changes in ice conditions only to a small extent. The only significant correlation with sea ice condition of the Greenland Sea was noted in August. Lack of the discussed correlation in summer is attributed to the influence of insolation and radiation factors whose importance increase during the polar day (as indicated in research by Lefauconnier et al. (1999)).
EN
Winter snow cover in south Spitsbergen is modelled by three main factors: snow precipitation, strong winds which blow out large amounts of snow (locally snow deposition occurs) and winter thaws of short duration. Slight snow melting during thaws causes development of ice-crust layers in a frozen snow cover. The ice-crust protects snow cover from blowing out. Moreover, ice-crust layers are very important in the investigations of snow stratigraphy. In the winter snow cover of 1992/1993, eight layers of ice-crust were observed. The occurrence of atmospheric precipitation is highly associated with the type of atmospheric circulation in the area of south Spitsbergen. In the analysis of statistic relations between circulation and precipitation, circulation typology of Niedźwiedź (1997) was applied. In the period June 1992 - May 1993, as many as 74% of annual solid precipitation was associated with the occurrence of three types of circulation (C-10, C-8 and C-3). The circulations C-4, C-6 and C-1 gave only 4% of annual precipitation. The winter season 1992/1993 is connected with typical meteorological conditions that occur in the south part of Spitsbergen. In the area of Polish Polar Station, four phases of development and degradation of snow cover were distinguished: - intensive blowing out of snow (October - January), - small increase of snow cover thickness (February - March), - considerable increase of snow cover thickness (March - May), - thaws (May, 25th - June, 28th). The thickness of snow cover depended on the altitude and local conditions. Considerable differences were determined in snow thickness at two sites located in small distance from each other (500 m), both close to the seacoast (Fig. 1). Water equivalent of the snow cover at Polish Polar Station (8 m a.s.l.) at the end of winter was only 150 mm, whereas at Fugle site (5 m a.s.l.) it was 2.5 times higher (378 mm). These values were much higher on the glaciers; Hans Glacier in the ELA zone (300 m a.s.l.) - 276 mm and in the accumulation zone (450 m a.s.l.) - 1459 mm; Amundsenisen Plateau (700 m a.s.l.) - 1293 mm.
15
Content available remote Glacials, interglacials and ice covers
EN
A stratigraphic approach to the Quaternary which takes into account the changes in climate (Pleistocene cold stages = glacials, and Pleistocene warm stages = interglacials, with considerable variations in temperature and humidity), and appearance and disappearance of ice sheets in certain areas. Reduced ice sheets might have remained during the interglacials.
EN
This paper presents results of ablation measurements carried out on the Waldemar Glacier (Oscar II land, NW Spitsbergen) during the three-summer seasons (23rd July - 20th August) 1977, 1978 and 1980. The measurements were conducted along longitudinal profile (stakes no. I to X), which begun a little above the glacier terminus (130 m a.s.I) and ended in the firn field (376 m a.s.I.). In addition, ablation measurements were also carried out along two transitional profiles. The first profile (stakes no. XI to XX) was located at the altitude of about 200 m a.s.I., and the second one (stakes no. XXII-XXX) at the altitude of 300-330 m a.s.I. (Fig.1). Data of general weather conditions come from the base station located in the Kaffiöyra Plain (Table 1), while for the glacier available are only the temperature data from two stations: LW1 (130 m a.s.I.) and LW2 (380 m a.s.I.) (Table 2). The mean seasonal values of ablation (in cm of water equivalent) are presented in Table 3. Ablation shows a relationship with the altitude a.s.I and with the distance from the glacier terminus. The mean seasonal 3-year ablation values (from the common period 23rd July - 20th August) in the stake no. I was equal to 85.2 cm, while in the stake no. X only 37.2 cm (Table 3). The hypsometric lapse rate of ablation was equal to about 19.51 cm! 100 m (Fig. 2). The mean ablation values computed for transitional profiles were equal to 60.0 cm (for the lower profile) and 53.2 cm (for the upper profile). The relationship of ablation with altitude is a consequence of decreasing temperature with the rise of altitude. On the Waldemar Glacier the rate of temperature decreasing is equal to 0.52°C/100 m. Our investigations confirm the well-known fact that the ablation is strongly influenced by the solar-radiation conditions. On the mountain glaciers solar irradiance causes the differentiation of ablation processes along the longitudinal profile. However, it was also observed that on the Waldemar Glacier (and probably on majority of the Spitsbergen glaciers) the highest ablation values are occurring under dynamical advection of warm and humid air, which often brings the abundant warm rain, as in the case of days 15 to 16 August 1980.
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