Snow Environments Research Articles

Estimating the costs of locomotion in snow for coyotes

Carnivores living in areas of deep snow face additional energy expenditures during winter owing to increased locomotory costs. Such costs may vary in function of snow depth and hardness (sinking depth of animal) and travel speed. We estimated energetic costs of locomotion through snow in wild coyotes (Canis latrans) using three coyote-sized domestic dogs (Canis familiaris) to develop regression models predicting heart rate (as surrogate for energy expenditure) in relation to sinking depth and travel speed. In the absence of snow, heart rates of dogs increased linearly with travel speed (R2 = 0.24), whereas when snow was present, track sinking depth affected heart rate substantially more than did travel speed. To assess whether our results with domestic dogs could help explain the behaviour of wild coyotes, we snow-tracked coyotes in southeastern Quebec, Canada, during two winters. During a normal harsh winter, coyotes relied on artificially packed snow (snowmobile and animal trails) more than during a mild winter. Coyotes typically exerted a fine-scale selection for snow depth and hardness that effectively reduced their sinking depth by ~2 cm. We estimated that travelling over snow increased coyote heart rate by 4%–6% in comparison with locomotion on hard surfaces, whereas fine-scale selection saved a similar amount of extra energy. We hypothesize that the use of snow packed by anthropogenic activities, especially snowmobile trails, may not only facilitate coyote movements in deep snow environments but also allow occupation of marginal habitats such as forested areas of northeastern North America.

Two types of matter economy for the wintering of evergreen shrubs in regions of heavy snowfall.

Plant adaptation to an environment subject to heavy snowfalls was investigated in four species of evergreen shrubs growing in a Fagus crenata forest in an area of Honshu on the Sea of Japan. These shrubs stored carbohydrates in some organs before the snowy season and were covered with snow for 4-5 months. Aucuba japonica var. borealis, Camellia rusticana, and Ilex crenata var. paludosa maintained a reserve of carbohydrates during the snowy season. In Daphniphyllum macropodum var. humile, the reserve of carbohydrates decreased during winter. The respiration rates in the first three species decreased from autumn to winter, whereas the decrease in D. macropodum was slight. It was found that the first three species could use reserve carbohydrates for the growth of new shoots after the thaw, whereas in the last species the growth of new shoots depends on high photosynthetic activity in late spring. Our findings suggest some types of matter economy in evergreen shrubs for wintering in an environment of heavy snow.

Physical properties of the seasonal snow cover in Dronning Maud Land, East Antarctica

AbstractSnow stratigraphy was analyzed in the Maudheimvidda area of western Dronning Maud Land, East Antarctica, during austral summer 1999/2000 as a part of the Finnish Antarctic Research Programme (FINNARP). Measurements were made in shallow (1–2m) snow pits along a 350 km transect from the coast to the polar plateau, covering at least one annual cycle and an elevation range from sea level to about 2500 m. The aim of the study is to document spatial and temporal variations in snow-cover properties, with the further aim of relating these variations to environmental factors and to patterns observable by remote sensing. The measurements suggest five principal snow zones: (i) sea ice, (ii) the seaward edge zone of the ice shelf, (iii) the inner parts of the ice shelf, (iv) the snow cover above the grounding line and (v) the local topographic highs. Local topographic highs such as ice domes and ice rises differ from other snow environments: the snow is less densely packed, possibly an indication of locally reduced speed of the katabatic outflow. Fewer and thinner crusts on the topographic highs are consistent with RADARSAT backscatter variations.

Snow Ecology: An Interdisciplinary Examination of Snow-covered Ecosystems.

Jones, H.G., Pomeroy, J.W., Walker, D.A., Hoham, R. ( eds ) ( 2000 ) Snow Ecology: An Interdisciplinary Examination of Snow-covered Ecosystems. Pp. xx + 378 . Cambridge University Press , Cambridge . ISBN 521-58483-3 . Price £50 (hardback). At last here is a book that considers the big picture of snow ecology, elegantly linking the physical, chemical and biological disciplines that relate to the functioning of snow and snow-covered ecosystems. Seasonal snow cover can have a phenomenal impact on weather patterns on a global scale. Groisman and Davies emphasize the importance of understanding the relationship between snow cover and climate, especially pertinent in the face of climate change. Variations in snow cover will affect the physical properties of snow. Pomeroy and Brun discuss the physical characteristics of snow cover and the unique properties of snow that enable it to sustain life. Tranter and Jones then demonstrate how the chemical composition of snow contributes to biogeochemical cycles, affecting the supply of nutrients and chemicals to terrestrial and aquatic ecosystems. Physical changes in the snow cover and climate influence snow chemistry, which in turn can be affected by biological activity. The remaining chapters cover the biology of snow, starting with microbial ecology of ice and snow by Hoham and Duval, which primarily concentrates on snow algae. Aitchison investigates the effect of snow cover on small animals, invertebrates and vertebrates. Walker, Billings and de Molenaar provide a synthesis of past work on tundra snow–vegetation interactions, outlining the influence of snow on plant distribution, physiology and growth. In the final chapter on dendrochronology, Bégin and Boivin demonstrate how the development of irregular tree-growth forms and their reactions to injuries can be used to reconstruct local past snow conditions. Each chapter can be read in isolation, although they flow smoothly from one to the other. But why is the subject of snow ecology so important and how do all the disciplines integrate? Interpreting the book as a whole, the following synthesis can be proposed. Ecosystems on a global scale are indirectly affected by seasonal snow cover, which plays an inherent part in the climate system. Areas that have experienced some of the most drastic changes in snow cover, linked to global temperature trends, tend to be concentrated in the polar and subpolar regions of the Northern Hemisphere. Snow cover in these regions is fundamental and shapes ecosystems that are highly sensitive to change. Perturbations to some of these nival communities will have feedback links to the climate system. Changes in the annual snow cover regime will have a direct effect on the physical environment; gaining an understanding of the unique properties of snow will help to explain how ecological communities are able to occupy the snowpack. Transformations of snow cover – as controlled by a combination of snow settling and snow metamorphism – and phase change are some of the processes that are vital to life. Snow depth, crystal structure and density contribute to the thermal conductivity and degree of light penetration of snow, additional characteristics that influence survival of nival communities. Processes that govern snowfall formation and snow crystal structure are not only important in terms of interpreting the spatial distribution of the snow environment, but also form the basis of understanding snow chemistry. The chemical composition of snow is often integral to terrestrial and aquatic ecosystems, affecting biological activity. In turn, micro-organisms can significantly affect the dynamics of snow chemistry in the snowpack. In addition, snow algae have been shown to alter the physical properties of snow, affecting the mass balance of a Himalayan glacier by reducing surface albedo. Variation of albedo is also cited as an important factor in the surface energy balance for plants and animals. The main governing factor affecting plant distribution in Arctic and alpine regions is snow, partly due to its effect on soil thermal properties. Subnivean activity by small mammals is also an influence, as snow accumulates nutrients by the incorporation of biological debris; distribution of solute in the snowpack before melt is affected by snow metamorphism. Vegetation can in turn increase dry deposition at ground level by the removal of adsorbed chemical species within the canopies via throughfall. The book provides an excellent basis for anyone entering, and indeed already established in the field of snow ecology. It admirably tackles the ambitious task of describing some of the major principles governing snow ecosystems. It would have been useful to see a chapter tying all the processes together within the context of climate change and anthropogenic pollution, with a flow diagram highlighting some of the interactions. In the final analysis, Snow Ecology emphasizes the need for future research within this field to be more multidisciplinary, challenging the current approach to studying snow ecosystems – just what a good textbook should do!

A Community of Snow Algae on a Himalayan Glacier: Change of Algal Biomass and Community Structure with Altitude

A community of snow algae on a Himalayan glacier, the Yala Glacier (5100-5700 m a.s.l.), Langtang region of Nepal Himalaya, were quantitatively analyzed. This is the first report on snow algae from the Himalayan region. In this glacier, 11 species of snow algae were observed: Chloromonas sp., Trochiscia sp., Mesotaenium berggrenii, Cylindrocystis brébissonii, Koliella sp., Ancylonema nol-denskioeldii, Raphidonema sp., three Oscillatoriacean algae, and one unknown coccoid alga.The algal biomass estimated by the total cell volume rapidly decreased as the altitude increased. In particular, the rate of decrease of algal biomass was larger in the upper snow environment than in the lower ice environment. The structure of algal community represented by the proportion of each species to the total algal biomass also differed by altitude. From the difference of the algal community, we divided the glacier into three zones: the Lower Zone (5100-5200 m a.s.l.; stable ice-environment), with 7 species dominated by Cylindrocystis brébissonii; the Middle Zone (5200-5300 m a.s.l.; unstable transition area between ice-environment and snow-environment), with 11 species dominated by Mesotaenium berggrenii; and the Upper Zone (5300-5430 m a.s.l.; stable snow-environment), with 4 species dominated by Trochiscia sp. This vertical zonation of the algal community type and biomass may reflect the difference in summer climatic conditions with altitude. Species number and Simpson's diversity index was highest in the Middle Zone where environmental conditions frequently changed. Our results seems to agree with the intermediate disturbance hypothesis.Since the snow algae in the accumulation area (>5250 m a.s.l.) of the glacier is annually stored in glacial strata, the algal biomass and community structure recorded in glacier ice-cores can be a new information source for the studies on past climate change in this region.

Comments on "Effect of wet snow an the null-reference ILS system"

The subject paper (July 1993) has raised some issues regarding the probability of the Instrument Landing System (ILS) radiating out-of-tolerance vertical guidance signals. An independent study has substantiated the findings of that paper and adds further concern regarding some FAA ILS snow procedures. The principal conclusions of this paper are: 1) an analysis, based on Walton's discovery of rare snow conditions that cause the null-reference ILS antenna image to disappear, indicates that these conditions can cause out-of-tolerance guidance signals, 2) operation without a monitor of the image radiation can result in signal-in-space guidance signal errors that are significantly beyond the intended limit values, and 3) the integrity of image glide path equipment in snow environments does not satisfy the ILS integrity requirements. >

Camille Flammarion und der Zweite Hauptsatz der Thermodynamik

AbstractIn Camille Flammarion's book La fin du monde, published in 1894, we find the picture shown in fig. 2: Some poorly dressed people, including a mother with her child, are shivering with cold in an extremely hostile environment of ice and snow. In two wide‐spread German history of science textbooks, this picture is given as an illustration of the pessimistic conclusions that some nineteenth century physicists (among them Hermann von Helmholtz) had drawn from the Second Law of Thermodynamics. They believed that in a remote future, the entropy of the universe would grow to a maximum, and all available energy would be transformed into heat. This apocalyptic vision was often called “heat death”, but as the average temperature would then be very low, the expression “cold death” was used as well.By analysing Flammarion's text, it is shown that he was not a supporter of this vision of the end of the world. According to Flammarion, mankind would die of cold as a consequence of the lack of water vapour in the atmosphere, and this would occur about twenty million years before the exhaustion of the sun as a source of energy. The use of this picture as an illustration of the heat death (or cold death) theory derived from thermodynamics is a misinterpretation that reminds of the erroneous assumptions that were expressed with regard to another picture by Flammarion (fig. 1). This illustration stemming from L'Atmosphére: Météorologie populaire (Paris 1888) was for many years (and sometimes is still) falsely considered as a medieval German woodcut.

Late‐Holocene Development of Subarctic Ombrotrophic Peatlands: Allogenic and Autogenic Succession

Ombrotrophic peatlands that developed on islands in Clearwater Lake, a large subarctic lake in northern Quebec, provide evidence of long—term community stability and successional change. Repeated alternations of regeneration cycles of Sphagnum cushions and black spruce (Picea mariana [Mill.]BSP.) over the last 5050 14C years of peatland development suggest climate, self—building mechanisms, and cyclic—autogenic succession as the dominant active factors operating in the absence of external disturbance such as fire. During the last several thousand years, self—perpetuating vegetation cycles have occurred at variable periodicity and have been controlled primarily by local ecological conditions whose existence is marked by differential peat accumulation rates. Water supply for peat production, in the absence of water table in most sites, was controlled by snow availability, precipitation, and atmospheric humidity from the large lake. Allogenic succession, illustrated by the community shifts from Sphagnum girgensohnii—Picea to S. russowii—Picea, S. fuscum—Picea, and lichen—heath, has been initiated by climate, and more particularly by continuous peat accumulation enhancing, as time passed, the ecological gradient from moist, snow—protected conditions to snowless, exposed conditions. In contrast, absence of such changes at some sites characterized by a uniform, self—regenerated S. fuscum—Picea assemblage suggests that autogenic succession has been an active driving mechanism in community persistence over several thousand years. Long—term trends in peatland development toward topographic equilibrium and late Holocene cooling best explain the gradual phasing—out of the vegetation cycles. Natural deforestation over the last 2000 14C years may have triggered a negative feedback process by changing the winter snow environment and the associated thermal soil regime. The ensuing peat fossilization, permafrost aggradation, and ice—wedge development at the peatland surface are all events consistent with the occurrence of this process. Present growth of the peatland pproceeds mostly along the margins, where levelling of the topographic profile is not yet completed.

Transition of A. sachalinensis plantation and snow environment in a heavy snow and cold area

Transition of A. sachalinensis plantation and snow environment in a heavy snow and cold area

北安曇・姫川流域における深雪気候と地域文北

(1) The Himekawa drainage area is one of the most heavy snow area in Japan with annual cover of 1.5-4.0m. This area is divided into two sub-areas, the northern and soutern parts, at Nakatsuchi, Otari Village by the depth of snow and the time of melting. In the southern part, the snow is very dry because the altitude is very high with very low temperature. The snow cover is the deepest in late February or early March and last to the middle of April. On the other hand, in the northern part, the snow is very wet because the altitude is very low with higher temperature than the south. And the snow cover is the deepest in late January or early February and it lasts to the early April, a month earlier than the south. For these reasons, the ways of removing snow on the roofs and of melting snow on the field and the kind of decorations for the New Year are different between two parts. Furthermore, the way and tools of snow treading to keep paths in the snow are different between two parts by the snow depth and topographic conditions.(2) Agricultural land utilization of this Himekawa area is restricted very strongly by the continuous show cover duration which reaches 120 days per year. Therefore, people in this area keep watching Yukigata (the shape of snow patches on the mountain high slopes) and common sayings which predict weather condition very valuably to make their original agricultural calendar by their traditions. Furthermore, they melt snow artificially to advance the season of seeding ricer and they contrive the way of seeding and cropping wheats which does not adapt to this area. From the viewpoints of the land utilization for forestry, the snow decrease the values of wood by bending trunks and breaking branches. On the other hand, the snow cover gives advantages for forestry such as preventing frost heaving, supplying water and preparing the roads to transport lumbers by sledding.People use snow as insulation for storing vegetables and as fields for sledding and skiing. Ski industries have been growing quickly since the middle of 1960's by developing and improving ski grounds, facilities, and accomodations in this area and by increasing numbers of trains on Oito-Line, Eastern Japanese Railways. As a result, industries and structures of population in this area have greatly changed.(3) It is recongnized that some cultures have been spread into this Kita-Azumi area from Toyama and Niigata prefectures. Technology of production such as Ecchu-Shibari (a way of bundling up harvested rice straws) and the way of making a charcoal kiln and life styles such as tree fences for wind breaking are spread from Toyama Prefecture. On the other hand, cultures for food such as Sasa-Zushi and Sasa-Dango (a kind of regional Sushi and dumpling wrapped by dwarf bamboo leaves) and Iwashino-Tsukedome (a salted sardine for preserving), a way of building houses protecting heavy snow cover and some technology of manufacturing sleds and skies are spread from Niigata Prefecture.Because of same natural environment of deep snow, the characterized local culture of this Kita-Azumi area was created by cultural interchange to Niigata Prefecture. Especially, in the settlements of Oami Todo and Yokokawa, Kita-Otari districts, Otari Village, which are located very close to the boundary to Niigata Prefecture, there are very strong effects of the Echigo (Niigata Prefecture) Culture.

The Tundra Microclimate During Snow-Melt at Barrow, Alaska

The microclimate of the tundra during spring of 1971 (29 May to 17 June) at Barrow, is described and analysed in terms of the heat balance at the terrestrial surface and the effects of terrain parameters on the heat balance components. Changes through the snow-melting period are large. Within 2 weeks, 35 cm of snow are removed, soil interface temperatures increase by 15°C and the dry snow environment is replaced by a saturated water-soaked tundra surface. As a result, evaporation rates are high: up to 6 mm/day occurs immediately after the snow melt. The latent heat required for this is 40 times higher than during the pre-melting period.