Wyniki wyszukiwania - Biblioteka Nauki

1

Snow accumulation on Kaffiøyra glaciers

100%

Sobota I. , Grześ M.

Landform Analysis

|

2007

|

tom Vol. 5

143--145

2

Distribution of snow accumulation on some glaciers of Spitsbergen

88%

Grabiec M. , Leszkiewicz J. , Głowacki P. , Jania J. , Grabiec M. , Leszkiewicz J. , Głowacki P. , Jania J.

|

nr 4

3

Snow distribution patterns on Svalbard glaciers derived from radio-echo soundings

75%

Grabiec M. , Puczko D. , Budzik T. , Gajek G.

Polish Polar Research

|

2011

|

tom 32

|

nr 4

4

Warunki meteorologiczne i wybrane problemy akumulacji śniegu na Równinie Kaffioyra (NW Spitsbergen) w okresie od lipca 2001do kwietnia 2002 roku

75%

Sobota I.

Problemy Klimatologii Polarnej

|

2003

|

tom nr 13

139-149

EN

The paper presents the results of meteorological measurements carried out in the Kaffioyra Plain in the summer season of 2001 and in the period form July 2001 to April 2002. The main meteorological observations were conducted in N.Copernicus Polar Station. situated in northern part of the Kaffioyra (NW Spitsbergen). The paper also presents the results of snow accumulation measurements on the Waldemar Glacier and Irene Glacier. which are located at Kaffioyra Region. The mean air temperature in the summer period (21.07. to 31.08.2001) was 5.9°C and was visibly higher then the long-term average. The sum of precipitation in this time was 37 mm and was lowest then the long-term average. The comparison between summer season 2001 and mean values from the years 1975-2001 in the common period shows that this season was characterised by air temperature higher then many year?s values. The mean air temperature in the period from July 2001 to April 2002 was -5.3°C. The highest monthly air temperature was in August (5.2°C) and the lowest was in March (-14.7°C). The sum of precipitation in the time with snow cover at Kaffioyra was 86.6 mm. Investigations of a snow cover on the Kaffioyra have been carried out in two points. Snow cover on the Kaffioyra was started to form in the end of September. Winter snow accumulation equal to 91 cm in point B and 18 cm in point B. The changes of snow thickness was depended from a velocity of wind. Investigations of a snow cover on the Waldemar Glacier and the Irene Glacier have been carried out form September 2001 to April 2002. The Waldemar Glacier and Irene Glacier are located in the northern part of the Oscar II Land (Northwestern Spitsbergen). In spite of small areas of these glaciers. there is great spatial variation in snow deposition. During the winter 2002 the highest snow accumulation of the Waldemar Glacier was noted in the northern part of the glacier. both on its accumulation part and at foot of Grafjellet which surrounds the glacier from the south. The lowest thickness of a snow cover was observed at terminus of the glacier and at foot of the medial moraine (up to 40 cm w.e.). On the Irene Glacier the highest snow accumulation was observed in two accumulation parts (up to 120 cm w.e.). The lowest thickness of a snow cover was observed at terminus of the glacier and at central part of glacier (up to 20 cm w.e.). Winter snow accumulation of the Waldemar Glacier was equal to 63.2 cm w.e. On the Irene glacier it was similar and equal to 64.7 cm w.e.

5

Weighting alternatives for water stable isotopes: Statistical comparisonbetween station- and fi rn/ice-records

63%

Hatvani I. G. , Kern Z.

|

6

Distribution of snow accumulation on some glaciers of Spitsbergen

63%

Grabiec M. , Leszkiewicz J. , Glowacki P. , Jania J.

Polish Polar Research

|

2006

|

tom 27

|

nr 4

309-326

EN

We describe the spatial variability of snow accumulation on three selected glaciers in Spitsbergen (Hansbreen, Werenskioldbreen and Aavatsmarkbreen) in the winter seasons of 1988/89, 1998/99 and 2001/2002 respectively. The distribution of snow cover is determined by the interrelationships between the direction of the glacier axes and the dominant easterly winds. The snow distribution is regular on the glaciers located E-W, but is more complicated on the glaciers located meridionally. The western part of glaciers is more predisposed to the snow accumulation than the eastern. This is due to snowdrift intensity. Statistical relationships between snow accumulation, deviation of accumulation from the mean values and accumulation variability related to topographic parameters such as: altitude, slope inclination, aspect, slope curvature and distance from the edge of the glacier have been determined. The only significant relations occured between snow accumulation and altitude (r = 0.64-0.91).

7

Charakterystyka zmienności pokrywy śnieżnej w sezonie letnim (ablacyjnym) na lodowcach rejonu Kaffioyry (NW Spitsbergen)

63%

Sobota I.

Problemy Klimatologii Polarnej

|

2007

|

tom nr 17

135-145

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.

8

The features of snow loads on building roofs

63%

Pichugin S. F. , Dryzhyruk Y. V. , Popovich N. M. , Chernetska I. V.

Czasopismo Techniczne. Budownictwo

|

2015

|

tom Y. 112, iss. 2-B

441--449

EN

In this paper the probabilistic model of the snow accumulation on the roofs with height discontinuity was worked out, the decreasing coefficient for the snow load weight was received and the ways of their application in the designing were elaborated. The probabilistic model for impulse stochastic process of snowfall sequence was developed. Data from meteorological stations in Ukraine allow determination of statistical characteristics: average annual snowfall amount and exponential distribution of values of one snowfall. The law of intensity distribution of snow melting has been determined experimentally. The territorial zoning map of Ukraine by characteristic values of the snow load on the roofs that emanate heat was developed.

PL

W pracy opracowano probablilistyczny model akumulacji śniegu przy zmianie wysokości dachu, otrzymano współczynnik zmniejszający dla obciążenia śniegiem oraz wypracowano sposoby jego wykorzystania w projektowaniu. Rozwinięto model probablistyczny dla impulsowego procesu stochastycznego dotyczącego opadu śniegu. Dane ze stacji meteorologicznych na Ukrainie pozwoliły określić charakterystyki statystyczne: średni roczny opad śniegu i wykładniczy rozkład wielkości w pojedynczym opadzie śniegu. Prawo rozkładu intensywności topnienia śniegu zostało określone eksperymentalnie. Rozwinięto mapę stref terytorialnych Ukrainy za pomocą charakterystycznych wielkości obciążenia śniegiem dachów wydzielających ciepło.

9

Związek akumulacji śniegu na lodowcach północno-zachodniego Spitsbergenu z cyrkulacją atmosferyczną, opadami i temperaturą powietrza w okresach zimowych

63%

Grabiec M.

Problemy Klimatologii Polarnej

|

2003

|

tom nr 13

161-171

EN

This work attempts to determine connections between glaciers' winter mass balance and meteorological factors of winter seasons. Detailed analysis was carried out between the snow accumulation of Austre Broggerbreen and the meteorological data from Ny-Alesund station (Kongsfjord region) from 1975 to 1998. Relation has been found between the snow accumulation and warm and humid air masses frequency in winter seasons (X - V). Those masses are mainly from southerly and southwesterly directions for Svalbard. The winter mass balance shows very clear connection with air temperature and precipitation factors of winter seasons (sum of winter precipitation, number of days with precipitation intensity >= 5 mm per day, winter mean air temperature, and number of days with maximum daily air temperature >= 0°C). A particularly close connection is observed between winter mass balance and number of days with precipitation intensity >= 5 mm per day at the positive daily maximum air temperature (LPTmax) (r = 0.81) - Fig. 8. The winter mass balance multiply regression (Wb) was worked with the use of the elementary meteorological factors: the average winter temperature (T) and the sum of precipitation in the same period (P). On the basis of the multiply regression of winter balance it is possible to predict snow accumulation changes. Over the next 50 years the winter snow accumulation of Austre Broggerbreen could increase about 15% if the scenario of climatic changes by Hanssen-Bauer (2002b) is used. If, in addition, one assumes the stability of ablation, the mass balance of glaciers will rise by 24%, but the mass balance will still be negative.

10

Winter snow accumulation and discharge from the Waldemar Glacier Northwestern Spitsbergen in 1996-1998

63%

Grzes M. , Sobota I.

|

nr 1

11

Effects of freezing and freeze-thaw cycles on soil microbial biomass and nutrient dynamics under different snow gradients in an Alpine meadow (Tibetan Plateau)

51%

Liu L. , Wu Y. , Wu N. , Xu J. , Mao Y. , Luo P. , Zhang L.

Polish Journal of Ecology

|

2010

|

tom 58

|

nr 4

EN

In alpine zones, cold season processes, particularly those associated with snow accumulation and ablation, have a central role in ecosystem functioning. However, we know very little about soil carbon and nitrogen processes under the snowpack in these ecosystems, including the Tibetan Plateau. We conducted an experiment comparing three snow regimes (11 m × 1 m plots) of different snow depths and durations at an altitude of 4,100 m in the Minshan Range on the eastern Tibetan Plateau. The three snow regimes included a shallow and short duration snowpack (SS; depth <10 cm), a moderate snow depth and medium duration snowpack (MS; depth <20 cm), as well as a deep and long duration snowpack (DS; depth > 30 cm). This study explores the effects of different snow conditions on soil temperature, and further describes the sequence and timing of dissolved nutrients and microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) in soils under different snow regimes during the autumn-winter transition (i.e. November 7, 2008 – March 7, 2009). Three successive phases of temperature change were distinguished: I – initial decline – soil temperatures dropped steadily from 4°C to about 0°C at the same rate for all three snow regimes; II – moderate freezing – soil temperatures fluctuated between 0°C and –7°C under all three snow regimes; III – multiple freeze-thaw cycles took place in the SS and MS regimes, but permanent freezing occurred in the DS regime. Under moderate freezing, we found that soil temperature fluctuation was an essential factor for the transformation of soil C and N. Our results indicate that larger temperature fluctuations correlate with a greater increase in dissolved organic nitrogen (DON) content. Dissolved organic carbon (DOC) content increased markedly only under the most drastic temperature fluctuations. In contrast, MBC content increased significantly only when soil temperatures were relatively steady. Under the permanent freezing, only a large number of freeze-thaw cycles caused a significant decline of NO₃⁻–N and DOC concentrations. DON content declined markedly under permanent freezing and multiple freeze-thaw cycles. However, MBC content declined significantly only under permanent freezing. Ultimately, multiple freeze-thaw cycles resulted in the export of dissolved nutrients (organic and inorganic nitrogen) from the alpine ecosystem which had previously accumulated in the moderate freezing phase of the soil.