H. G. Jones

Snow ecology : an interdisciplinary examination of snow-covered ecosystems

Acknowledgements 1. Snow cover and the climate system Pavel Ya. Groisman and T. D. Davies 2. Physical properties of snow John Pomeroy and E. Brun 3. The chemistry of snow Martyn Tranter and H. G. Jones 4. Microbial ecology of snow and fresh-water ice with emphasis on snow algae Ron Hoham and Brian Duval 5. The effect of snow cover on small animals C. W. Aitchison 6. Snow vegetation interactions in tundra environments D. A. Walker, W. D. Billings and J. G. de Molenaar 7. Tree-ring dating of past snow regimes Yves Begin and Simon Boivin Index.

Wind-Blown Snow: Sublimation, Transport and Changes to Polar Snow

In their hallmark work on the Antarctic blowing snow phenomenon, Budd et al. (1966) recounted a quote of Peary (1898) that still has relevance to interpretation of glacial phenomena: “There is one thing of special interest to the Glacialist — the transport of snow on the ice-cap by the wind” Following Peary’s reasoning, the blowing snow phenomenon was studied intensively in the Antarctic several decades ago (Lister, 1960; Mellor and Radok, 1960; Dingle and Radok, 1961; Budd et al, 1966) with more recent studies by Kobayashi (1978), Takahashi (1985) and Moore et al. (1994). Other work of similar nature has been conducted in the Arctic (Dyunin, 1959; Benson, 1982; Tabier et al, 1990b; Benson and Sturm, 1993). Blowing snow is quite frequent in the Antarctic, Dalrymple (1966) noted snow transport occurred from 30–55% of the time in the South Pole region, increasing to 55–65% of the time at Byrd Station. Fujii (1981) found snow accumulation to occur in only one or two out of every three years in East Antarctica because of wind erosion and sublimation. At Mzuho Station, East Antarctica, Takahashi et al. (1994) estimated that of an annual snowfall of 140–260 mm water equivalent, 100 rnm/year is eroded from surface snow and transported away by blowing snow and 50 mm/year sublimates.

Transformations of snow chemistry in the boreal forest: Accumulation and volatilization

This paper examines the processes and dynamics of ecologically-important inorganic chemical (primarily NO 3 -N) accumulation and loss in boreal forest snow during the cold winter period at a northern and southern location in the boreal forest of western Canada, Field observations from Inuvik, Northwest Territories and Waskesiu, Saskatchewan, Canada were used to link chemical transformations and physical processes in boreal forest snow. Data on the disposition and overwinter transformation of snow water equivalent, NO 3 - , SO 4 2- and other major ions were examined. No evidence of enhanced dry deposition of chemical species to intercepted snow was found at either site except where high atmospheric aerosol concentrations prevailed. At Inuvik, concentrations of SO 4 2- and Cl - were five to six times higher in intercepted snow than in surface snow away from the trees. SO 4 -S and Cl loads at Inuvik were correspondingly enhanced three-fold within the nearest 0.5 m to individual tree stems. Measurements of snow affected by canopy interception without rapid sublimation provided no evidence of ion volatilization from intercepted snow. Where intercepted snow sublimation rates were significant, ion loads in sub-canopy snow suggested that NO 3 - volatized with an efficiency of about 62% per snow mass sublimated. Extrapolating this measurement from Waskesiu to sublimation losses observed in other southern boreal environments suggests that 19-25% of snow inputs of NO 3 - can be lost during intercepted snow sublimation. The amount of N lost during sublimation may be large in high-snowfall, high N load southern boreal forests (Quebec) where 0.42 kg NO 3 -N ha -1 is estimated as a possible seasonal NO 3 - volatilization. The sensitivity of the N fluxes to climate and forest canopy variation and implications of the winter N losses for N budgets in the boreal forest are discussed.