scholarly journals Chemical and algological composition of the snow cover at the mouth of the Onega river (White Sea basin)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ekaterina I. Kotova ◽  
Victoria Yu Topchaya
Keyword(s):  
Snow Cover ◽  
Suspended Matter ◽  
Suspended Solids ◽  
White Sea ◽  
Total Content ◽  
Cover Depth ◽  
White Sea Basin ◽  
Snow Cover Depth ◽  
Dissolved Form

Abstract In the study, the content and speciation of Mn, Pb, Cd, Zn, Cr, Ni, Co, Cu, and Fe in the snow cover at the mouth of the Onega river (White Sea basin) at the end of the winter periods in 2018, 2019 and 2020 were determined. Winter 2019 year was the snowiest, as the maximum values of the snow cover depth and water equivalent were almost two times higher than in all other years. The total content of suspended matter in the snow cover was 0.2–5.5 μg/L. Increased concentrations of suspended solids were identified near highways. Mn, Cr and Ni were present in the snow cover mainly in their dissolved form, while Fe, Pb and Co were mostly contained as solids. The algological composition of the snow cover was also studied.

scholarly journals Changes in Air Temperature and Snow Cover in Winter in Poland

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Arkadiusz M. Tomczyk ◽  
Ewa Bednorz ◽  
Katarzyna Szyga-Pluta
Keyword(s):  
Snow Cover ◽  
Air Temperature ◽  
Winter Season ◽  
Primary Objective ◽  
Climatic Conditions ◽  
Cover Depth ◽  
North Eastern ◽  
Northern Regions ◽  
Maximum Air Temperature ◽  
Snow Cover Depth

The primary objective of the paper was to characterize the climatic conditions in the winter season in Poland in the years 1966/67–2019/20. The study was based on daily values of minimum (Tmin) and maximum air temperature (Tmax), and daily values of snow cover depth. The study showed an increase in both Tmin and Tmax in winter. The most intensive changes were recorded in north-eastern and northern regions. The coldest winters were recorded in the first half of the analyzed multiannual period, exceptionally cold being winters 1969/70 and 1984/85. The warmest winters occurred in the second half of the analyzed period and among seasons with the highest mean Tmax, particularly winters 2019/20 and 1989/90 stood out. In the study period, a decrease in snow cover depth statistically significant in the majority of stations in Poland was determined, as well as its variability both within the winter season and multiannual.

scholarly journals Schrenk spruce leaf litter decomposition varies with snow depth in the Tianshan Mountains

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lu Gong ◽  
Xin Chen ◽  
Xueni Zhang ◽  
Xiaodong Yang ◽  
Yanjiang Cai
Keyword(s):  
Soil Properties ◽  
Snow Cover ◽  
Litter Decomposition ◽  
Growing Season ◽  
Temporal Variations ◽  
Tianshan Mountains ◽  
Cover Depth ◽  
C And N ◽  
Thaw Period ◽  
Snow Cover Depth

Abstract Seasonal snowfall, a sensitive climate factor and the main form of precipitation in arid areas, is important for forest material circulation and surface processes and profoundly impacts litter decomposition and element turnover. However, how the thickness and duration of snow cover affect litter decomposition and element release remain unclear. Thus, to understand the effects of snow on litter decomposition, fiber degradation and their relationships with soil properties, a field litterbag experiment was conducted under no, thin, medium, and thick snow cover in a Schrenk spruce (Picea schrenkiana) forest gap in the Tianshan Mountains. The snow cover period exhibited markedly lower rates of decomposition than the snow-free period. The litter lignin, cellulose and N concentrations in the pregrowing season and middle growing season were significantly higher than those in the deep-freeze period, and the litter C and P concentrations were significantly higher during the onset of the freeze–thaw period, deep-freeze period and thaw period than in the late growing season. The litter cellulose, C and N concentrations were significantly higher under thick snow cover than under no snow cover in most stages. Moreover, the correlations among litter mass, cellulose, lignin/cellulose and soil bulk density varied with snow cover depth. The temporal variations and snow cover depth affected the decomposition process significantly. The former affected lignin, cellulose and P, and the latter affected cellulose, C and N and changed the litter-soil properties relationship. These differences provide references for understanding how winter conditions affect material cycling and other ecological processes under climate change.

scholarly journals Loss of Total Phenol in Two Shrub Leaf Litter Species: The Dual Role of Alpine Forest Gap Disturbance

2019 ◽  
Author(s):  
Wei He ◽  
Wanqin Yang
Keyword(s):  
Snow Cover ◽  
Growing Season ◽  
Dual Role ◽  
Total Phenol ◽  
First Year ◽  
Forest Gap ◽  
Cover Depth ◽  
Forest Gaps ◽  
Alpine Forest ◽  
Snow Cover Depth

Alpine forest gaps can distribute snowfall, solar radiation and rainfall, thus inducing a heterogeneous hydrothermal microenvironment between the inside and outside areas of forest gaps. Additionally, the characteristics of the heterogeneous microenvironment could vary greatly across the gap location properties during winter and the growing season. To determine the response of total phenol loss (TPL) from the litter to alpine forest gap disturbance during decomposition, we conducted a field litterbag experiment within a representative fir (Abies faxoniana Rehd.) forest based on the gap location properties. The TPL and abundances of fungi and bacteria from two typical shrub species (willow, Salix paraplesia Schneid., and bamboo, Fargesia nitida (Mitford) Keng f.) were measured during the following periods over two years: snow formation (SF), snow cover (SC) snow melting (ST), the early growing season (EG) and the later growing season (LG). At the end of the study, we found that the snow cover depth, frequencies of the freeze-thaw cycle and the fungal copy g-1 to bacterial copy g-1 ratio had significant effects on the litter TPL. The abundances of fungi and bacteria decreased from the gap center to the closed canopy during the two SF, SC, ST and LG periods and reversed during the two EG periods. The TPL closely followed the same trend as the microbial abundance during the first year of incubation. In addition, both species had larger TPLs in the gap center during the first winter, first year and entire two years. These findings suggest that alpine forest gap formation accelerates litter TPL and plays a dual role during specific critical periods by distributing abiotic and biotic factors directly and indirectly. In conclusion, reduced snow cover depth and duration during winter warming under current climate change scenarios or as gaps vanish may slow litter TPL in alpine biomes.

scholarly journals Relationship Between the Development of Depth Hoar and Avalanche Release in the Tian Shan Mountains, China

1990 ◽  
Vol 36 (122) ◽  
pp. 37-40 ◽  
Author(s):  
Ma Weilin ◽  
Hu Ruji
Keyword(s):  
Snow Cover ◽  
Human Life ◽  
Cover Depth ◽  
National Economic ◽  
Optimum Depth ◽  
Tian Shan Mountains ◽  
The Mean ◽  
Economic Construction ◽  
Snow Cover Depth ◽  
Tian Shan

AbstractIn spring and winter, there is a considerable amount of solid precipitation in the western part of the Tian Shan mountains. Avalanches frequently occur here, and often endanger national economic construction and human life. Observation shows that the avalanche occurrences are closely related to the physical characteristics of the snow, especially to the development of depth hoar in the snow cover. The conditions for the development of depth hoar are determined by thickness of the snow cover, air temperature, ground-temperature regime, and the duration of negative temperatures. The results of this study have revealed that the optimum depth of snow cover for the development of depth hoar is about 80 cm in the Tian Shan mountains, and the mean maximum depth of the snow cover in this region is 78 cm. Therefore, depth hoar develops extraordinarily well. The thickness of depth hoar can reach more than 80% of the total snow-cover depth. That is one of the main reasons why avalanches still occur frequently under the conditions of a limited snow-cover depth in the western part of the Tian Shan mountains.

scholarly journals Snow depth in eastern Europe in relation to circulation patterns

2008 ◽  
Vol 48 ◽  
pp. 135-149 ◽  
Author(s):  
Ewa Bednorz ◽  
Joanna Wibig
Keyword(s):  
Eastern Europe ◽  
Snow Cover ◽  
Principal Components ◽  
Snow Depth ◽  
Circulation Pattern ◽  
Eastern European ◽  
Cover Depth ◽  
Circulation Patterns ◽  
Snow Cover Depth ◽  
Northeastern Europe

AbstractRotated principal components of the 500 hPa geopotential heights in the Euro-Atlantic sector are used as indicators of circulation pattern intensity. Daily snow-cover depth data for the years 1951–95 from 71 eastern European stations are examined. Maps of linear correlation coefficient between monthly change in snow depth and rotated principal components are presented. The positive and negative extremes of each circulation pattern are analyzed, and positive and negative snow-depth signals indicated. A daily analysis of relationships between snow depth and circulation pattern is performed for three locations. The strongest impact of the atmospheric circulation on changes in snow depth is observed in the south and west of the study area, where the eastern European (EE) and central European circulation patterns are found to have the greatest impact. The North Atlantic Oscillation (NAO) impact on the snow depth in eastern Europe is limited to the beginning and the end of winter. Snow cover has low variability in northeastern Europe (where the Scandinavian (SC) pattern is of greatest importance) and low sensitivity to change in the atmospheric circulation. The decrease in snow-cover depth observed in spring is related to the NAO, SC and EE patterns, the latter being important for snow-cover depth fluctuations over northeastern Europe in April.

scholarly journals Snow-cover depth, distribution and duration data from northeast Greenland obtained by continuous automatic digital photography

2001 ◽  
Vol 32 ◽  
pp. 102-108 ◽  
Author(s):  
Hanne H. Christiansen
Keyword(s):  
Snow Cover ◽  
Winter Season ◽  
Digital Photography ◽  
Small Scale ◽  
Remote Areas ◽  
Cover Depth ◽  
Wind Speeds ◽  
Winter Snow ◽  
Snow Drifting ◽  
Snow Cover Depth

AbstractDetailed data on autumn, winter and spring snow-cover conditions from remote areas are often difficult or very expensive to obtain. Therefore, an inexpensive method of digital photography was tested in high-Arctic Greenland. Automatic digital photography has provided daily data on snow distribution and snow depth for > 1 year from the Zackenberg area (74°30’ N) in northeast Greenland. A standard digital hand-held camera (Kodak Digital Science DC50) was equipped to become automatic; it is supplied with an “automatic finger” and an external power supply and built into a protecting box with additional solar panels on top, in order to secure continuous operation throughout the year. The daily photograph covers a 100 m transect through a seasonal snowpatch, and thus on an annual basis also yields information on snow-cover duration in the different vegetation zones of the snowpatch. The camera was installed in mid-August 1998. Photographs from the period mid-August 1998 to early September 1999 were collected and analyzed. All photos are taken at astronomic noon in order to use the daylight as long as possible into the winter season before the 24 h winter darkness begins in mid-November.The digital photographs yielded the following information for the year 1998/99: The first winter snowfall occurred on 18 October; small-scale snow redistribution by snow-drifting started when the winter snow cover was about 5 cm thick. The continuous winter snow cover lasted for a minimum of 170 days in the most snow-deprived areas downwind of the snowpatch, whereas snow in the centre of the snowpatch stayed on the ground for > 325 days, turning the snowpatch perennial in summer 1999.Meteorological data obtained close to the photographed snowpatch site, in combination with the snow-cover depth and distribution data derived from the photographs, show that at wind speeds (at 2 m height) of up to around 6 m s−1, only small-scale snow-drifting took place, when the snow cover was thin. Intense snowdrifting, however, took place at wind speeds of 8–13 m s−1, particularly when enough snow was available in the upwind area. The automatic continuous photography technique demonstrated here could be particularly useful in remote areas at high risk of avalanches during winter. It is an alternative to traditional snow monitoring achieved mainly by sonic sensors, snow pillows or manual measurements of snow depths Likewise, it can provide better areal information than most standard methods, which give only point measurements.

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