Boreal forest

Energy2green Wind And Solar Power System

Wind Energy DIY Guide

Get Instant Access

John W. Pomeroy and Richard J. Harding

Relevance and characteristics

The boreal forest in winter is a complex mosaic of land surface types varying from closed coniferous canopies, mixed-wood deciduous forests, sparsely vegetated areas (clearings, wetlands, clear-cuts, burns) to ice and snow-covered lakes. At roughly 20% of the earth's land area, the boreal forest is the largest terrestrial type of land cover and extends in a circumpolar band across North America, Europe, and Asia. Canada, Russia, and the Scandinavian countries are dominated by boreal forest, although in most cases it lies to the north of major population centers. Economic activities in the boreal forest center on forest harvesting, tourism, and mining, yet many boreal forests retain an indigenous aboriginal population whose members conduct aspects of a traditional hunting, fishing, and gathering lifestyle. The large number of lakes and rivers (up to 40% of some boreal regions are covered by water) promote fishing and water transport that has been fundamental to the development of northern Canada and Siberia. Recent environmental concerns focus on the extensive clearcutting of boreal forest in Canada and Russia, episodic acidic precipitation (including snow) from anthropogenic pollution, and the apprehension that climate warming will result in a major northward shift in the boreal climate zone and loss of forest lands in the southern boreal forest.

One distinction of the boreal forest in comparison to more temperate forests is its long snow-covered period and cold winter temperatures (Harding and Pomeroy,

1996). The depth, density, and duration of snow cover is ecologically important to mammals and various microbial life-forms in this forest; in some cases the snow cover provides a thermally moderated habitat, in others a means of avoiding predators (Jones et al., 2001). Boreal forest productivity and carbon cycling are strongly influenced by the supply of available nitrogen and soil moisture. Snow influences productivity and carbon cycling by providing, upon melt and infiltration, a significant portion of the annual water and inorganic nitrogen input (Pomeroy et al., 1999a). The global boreal forest exerts a strong control on climate and because of its low winter albedo, its removal and the resulting higher albedo in spring might result in a cooling of the Northern Hemisphere (Thomas andRowntree, 1992). Snowmelt provides 40-60% of annual streamflow from boreal forests, with increases in snowmelt runoff of 24-75% when forest cover is removed (Hetherington, 1987).

Boreal forest snow covers are strongly influenced by the forest canopy, its interception of snow and radiation and dampening of wind speed and mixing above the snowpack's surface. Pomeroy et al. (1998a) observed in a mixed range of boreal forest cover types that 20-65% of cumulative snowfall was intercepted in early winter, and 10-45% of snowfall sublimated over the season. Leaf area strongly controls interception efficiency (Hedstrom and Pomeroy, 1998) and clearcutting or conversion of coniferous stands to deciduous species reduces interception to insignificant levels (Pomeroy and Granger, 1997). The energetics of intercepted snow in the boreal forest have been studied by Nakai et al. (1993, 1994, 1999), Lundberg and Halldin (1994), Harding and Pomeroy (1996), Pomeroy and Dion (1996), Pomeroy et al. (1998a) and Parviainen and Pomeroy (2000). These studies show that the albedo of snow-covered forest canopies is low (<0.2), that sublimation rates up to 3 kg m-2 d-1 are possible from snow-covered canopies and that the direction and magnitude of sensible and latent heat fluxes are influenced by the presence of snow in the canopy because it represents a "wetter," cooler surface than a snow-free canopy. Parviainen and Pomeroy (2000) suggest that sublimation is driven by local-scale advection of sensible heat from exposed branches heated in the sun to intercepted snow clumps and that the efficiency of this advec-tion is related to the fractal geometry of intercepted snow clumps (Pomeroy and Schmidt, 1993).

Studies of snow under the canopy have been directed towards snow accumulation and melt prediction. Boreal forest snow covers have relatively low coefficients of variation of snow water equivalent (0.04-0.14) and maximum densities near 200 kg m-3 (Pomeroy et al., 1998b). At small scales, the snow water equivalent generally decreases with distance from coniferous tree stems (Woo and Steer, 1986; Jones, 1987; Sturm, 1992) and at stand scales it decreases with increasing canopy density (Kuz'min, 1960; Pomeroy and Gray, 1995). The forest cover attenuates the magnitude of incoming shortwave radiation and large-scale advection of warm air, reducing the "connectivity" between subcanopy snow and the atmosphere. Ni et al. (1997) and Pomeroy and Dion (1996) have measured and modeled winter sub-canopy radiation and found its magnitude greatly reduced from the above canopy values and strongly dependent on solar zenith angle, leaf area, and needle orientation. Typically, subcanopy net radiation in a mature conifer stand is one-tenth that above the canopy at the time of snowmelt. Davis et al. (1997), Hardy et al. (1997a, b), and Metcalfe and Buttle (1995,1998) have measured and modeled snow ablation under boreal forest canopies and conclude that though the magnitude of net radiation is strongly reduced in forests and decreases with increasing canopy density, it still comprises the largest component of the energy balance because the subcanopy snow albedo drops substantially during melt as forest leaf litter and debris in the snowpack are exposed and because subcanopy turbulent fluxes are extremely small in magnitude and usually of the opposite direction. Faria et al. (2000) suggest that because subcanopy snowmelt energy and the pre-melt snow water equivalent have a spatial covariance, depletion of the snow-covered area is accelerated as the covari-ance increases. Pomeroy and Granger (1997) compared melt rates in various forest types and found that melt timing was accelerated three-fold in a clear-cut compared to under a mature boreal forest canopy because the net melt energy was up to four times greater in the clear-cut.


Beartrap Creek (550 m a.s.l.) is a research basin, located at 54° N, 106° W, near the village of Waskesiu Lake, in Prince Albert National Park, Saskatchewan, Canada. The site has been the subject of intense investigations of boreal forest hydrology and climate under the Mackenzie global energy and water cycle experiment (MAGS), Prince Albert model forest hydrology study, and boreal ecosystem-atmosphere study (BOREAS). The region has a subhumid continental climate with six months of snow cover during a cold dry winter that experiences few melt events until April. Mean annual precipitation is 463 mm w.e. of which 33% occurs as winter snowfall. Topography is rolling with 700 m of local relief. Forest cover is typical of mature southern boreal forest: pine and mixed stands of aspen and white spruce on uplands, spruce, larch, and open muskeg in lowlands and about 15% covered by lakes.

The site studied is a mature, slightly open jack pine (Pinus banksiana) stand, 16-22 m tall with a winter leaf and stem area index of 2.2 m2 m-2 and canopy coverage of 82%. The fetch is level and uniform for about 100 m. Experiments were conducted in March, 1994 and 1996, using a canopy access tower (27 m). At the tower top two eddy correlation flux systems were installed, an Institute of Hydrology "Hydra" system for sensible and latent heat and a Gill Instruments "Solent" 3-axis sonic anemometer (Harding and Pomeroy, 1996). Above canopy net radiation and ground heat flux were measured using radiation and energy balance systems "REBS" net radiometers and heat flux plates and below canopy net radiation was measured using a Delta "T" tube net radiometer. Above canopy wind speed was measured using an RM Young propeller anemometer and temperature using a Vaisala HMP35CF hygro-thermometer. The intercepted snow load was measured using a suspended full size pine tree, which was weighed with an in-line force transducer (Hedstrom and Pomeroy, 1998). Weight of snow on the tree (kg) was converted to an areal mass (kg m-2) using an empirical conversion developed from comparing event-based snow interception on the single tree to areal interception determined from above canopy snowfall measurements and changes in snow accumulation along a line of 25 snow survey points in subfreezing conditions.

Energy balance

Two sets of energy balance and related surface conditions are shown. Figure 3.11 shows sensible and latent heat flux measurements made with a Hydra and checked against a Solent sonic anemometer along with net radiation above the canopy over a five day period in late March 1994. Fresh snowfall resulted in an initial intercepted load of about 4.5 kg m-2 on 27 March which then sublimated in temperatures ranging from -13 to 0 ° C until the end of 29 March, when above freezing temperatures (5 °C) resulted in melt and the unloading of any remaining snow.

Daily maximum temperatures then increased dramatically to 17 °Con31 March resulting in some early melt under the canopy. Four days had high net radiation inputs, i.e. negative peaks ranging from -450 to -500 W m-2, while 28 March was overcast with a peak net radiation of only -100 W m-2. When snow was in the canopy (27-29 March), daytime latent heat fluxes were directed away from the surface at approximately one-half the magnitude of net radiation. Sensible heat fluxes over the snow-covered canopy were similar in magnitude and direction to latent fluxes on the high-insolation days (27 and 29 March) but negligible on 28 March when low insolation resulted in minimal canopy heating. When the canopy snow load ablated (30 March), the daytime magnitude of sensible heat flux remained half that of net radiation but latent heat became negligible early in the day and directed downward later in the day. On the 31 March sensible heat behavior was unchanged but latent heat became directed upward at one-half the magnitude of sensible heat. This may reflect evaporation from melting snow beneath the canopy or, more likely given the magnitude, transpiration from the pine canopy induced by extraordinarily warm temperatures. The weighed tree did show some weight loss in this period reflecting desiccation due to evapotranspiration.

Figure 3.12 shows a consistently subfreezing sequence from the same site on 16-18 March 1996. A Solent sonic anemometer measured sensible heat fluxes (not latent) and the ablation rate of intercepted snow was measured using the weighed tree. The ablation rate was converted to equivalent energy units (flux) as if all the energy was consumed for phase change to vapor (a reasonable assumption given the -15 to -1 °C air temperatures).

0000 1200 0000 1200 0000 1200 0000 1200 0000 1200

Figure 3.11. Fluxes and climate measured above a jack pine stand in the southern boreal forest of Saskatchewan, Canada, March, 1994. (a) Latent heat, sensible heat, and net radiation fluxes measured five meters above an initially snow-covered canopy and (b) air temperature and wind speed measured five meters above the canopy.

0000 1200 0000 1200 0000 1200 0000 1200 0000 1200

Figure 3.11. Fluxes and climate measured above a jack pine stand in the southern boreal forest of Saskatchewan, Canada, March, 1994. (a) Latent heat, sensible heat, and net radiation fluxes measured five meters above an initially snow-covered canopy and (b) air temperature and wind speed measured five meters above the canopy.

Figure 3.12. Fluxes about a boreal jack pine canopy, Saskatchewan, Canada, March, 1996. (a) Sensible heat, net radiation, subcanopy net radiation, ground heat flux, and estimated latent heat flux from intercepted snow ablation. Above canopy fluxes were measured 5 m above the canopy, below canopy radiation 1 m above the snow cover and ground heat flux 5 cm into the soil. Intercepted snow ablation was measured using a weighed, suspended full-size jack pine tree. (b) Air temperature and wind speed measured 5 m above the pine canopy. Intercepted snow load measured using a weighed, suspended pine tree.

Figure 3.12. Fluxes about a boreal jack pine canopy, Saskatchewan, Canada, March, 1996. (a) Sensible heat, net radiation, subcanopy net radiation, ground heat flux, and estimated latent heat flux from intercepted snow ablation. Above canopy fluxes were measured 5 m above the canopy, below canopy radiation 1 m above the snow cover and ground heat flux 5 cm into the soil. Intercepted snow ablation was measured using a weighed, suspended full-size jack pine tree. (b) Air temperature and wind speed measured 5 m above the pine canopy. Intercepted snow load measured using a weighed, suspended pine tree.

Subcanopy net radiation and ground heat flux were also measured. An initial snow load of 4.2 kg m-2 ablated to 1.5 kg m-2 at the end of 16 March (strong winds, cold temperatures, and high insolation) and completely ablated by the end of 17 March. In this case sensible heat flux showed similar behavior to that in Fig. 3.11,at about one-half the magnitude of net radiation when the canopy is snow covered, increasing to three-quarters when snow free. Latent heat flux estimated from ablation equaled the sensible heat magnitude on the first (most snow-covered) day, then dropped to one-half the sensible magnitude on the second day and became negligible on the third day (snow-free canopy). Subcanopy net radiation was never more than one-tenth that of above canopy values, but remained slightly positive on 16 March when fresh snow covered the canopy and, along with a cool air mass, suppressed canopy temperatures and therefore downward longwave radiation. Ground heat fluxes were extremely small in magnitude and slowly fluctuated around zero.

Modeling aspects

The snow-covered canopy represents a separate snow layer that warrants its own mass and energy balance but is not represented by many land surface schemes (Essery, 1997). For instance, the ECMWF model recently used a routine that set the boreal forest canopy albedo to a high value (0.8) after a snowfall. When corrected to a much lower and appropriate value, air temperature predictions improved dramatically over the boreal region (Betts and Ball, 1997). CLASS and SiB are exceptions that do consider canopy snow, but calculate the snow interception process in a similar manner to rainfall and therefore underestimate intercepted load by an order of magnitude for large snowfalls (Pomeroy et al., 1998b). The interception models of Calder (1990) and Hedstrom and Pomeroy (1998) provide possible corrections to these schemes. Turbulent fluxes above a snow-covered canopy can be calculated using a resistance scheme with resistance set at 10 times the value of a rain-wetted canopy (Lundberg et al., 1998) or by varying the ratio of bulk transfer coefficients with snow load (Nakai et al., 1999). Parviainen and Pomeroy (2000) modeled the Beartrap Creek pine site using a nested control volume approach in which an energy and mass balance was conducted for an intercepted snow control volume, using the Reynolds number to calculate turbulent transfer between the intercepted snow and the atmosphere. The CLASS land surface scheme was then coupled to this small-scale calculation to calculate turbulent transfer between the canopy and atmosphere. Using a geometric radiative transfer model (GORT) to calculate subcanopy radiation (Ni et al., 1997) and SNTHERM to calculate snow-pack heat fluxes, snowmelt modeling was successful when snow surface albedo was reduced during melt and turbulent heat fluxes were given small values (Hardy etal, 1997b).


Ambach, W. (1974). The influence of cloudiness on the net radiation balance of a snow surface with high albedo. J. Glaciol., 13(67), 73-84.

Andreas, E L. (1989). A physical bound on the Bowen ratio. J. Appl. Meteorol., 28(11), 1252-1254.

Andreas, E. L and Cash, B. A. (1996). A new formulation for the Bowen ratio over saturated surfaces. J. Appl. Meteorol., 35(8), 1279-1289.

Bartelt, P. and Lehning, M. (2002). A physical SNOWPACK model for the Swiss avalanche warning; Part I: numerical model. Cold Reg. Sci. Technol., 35(3), 123-145.

Beljaars, A. C. M. and Holtslag, A. A. M. (1991). Flux parametrization and land surfaces in atmospheric models. J. Appl. Meteorol., 30, 327-341.

Betts, A. K. and Ball, J. H. (1997). Albedo over the boreal forest. J. Geophys. Res., 102(D24), 28 901-28 909.

Bintanja, R. (1998). The contribution of snowdrift sublimation to the surface mass balance of Antarctica. Ann. Glaciol., 27, 251-259.

Bintanja, R. and van den Broeke, M. R. (1995). Momentum and scalar transfer coefficients over aerodynamically smooth Antarctic surfaces. Bound.-Lay. Meteorol., 74, 89-111.

Bintanja, R. and van den Broeke, M. R. (1996). The influence of clouds on the radiation budget of ice and snow surfaces in Antarctica and Greenland in summer. Int. J. Climatol, 16, 1281-1296.

Bowling, L. C., Pomeroy, J. W., and Lettenmaier, D. P. (2004). Parameterisation of the sublimation of blowing snow in a macroscale hydrology model. J. Hydrometeor., 5, 745-762.

Brown, T. and Pomeroy, J. W. (1989). A blowing snow particle detector. Cold Reg. Sci. Technol., 16, 167-174.

Brun, E., David, P., Sudul, M., and Brunot, G. (1992). A numerical model to simulate snow-cover stratigraphy for operational avalanche forecasting, J. Glaciol., 38(128), 13-22.

Brun, E., Martin, E., Simon, V., Gendre, C., and Coleou, C. (1989). An energy and mass model of snow cover suitable for operational avalanche forecasting. J. Glaciol., 35(121), 333-342.

Brutsaert, W. (1975). On a derivable formula for long wave radiation from clear skies. Water Resources Res., 11, 742-744.

Calanca, P. and Heuberger, R. (1990). Glacial Climate Research in the Tianshan (ed. Ohmura, A. et al.). Zürcher Geographische Schriften (ZGS), Heft 38. Zürich: Swiss Federal Institute of Technology ETHZ, pp. 60-72.

Calder, I. R. (1990). Evaporation in the Uplands. Chichester: Wiley, p. 144.

Chamberlain, A. C. (1983). Roughness length of sea, sand and snow. Bound.-Lay. Meteorol, 25, 405-409.

Claussen, M. (1991). Local advection processes in the surface layer of the marginal ice zone. Bound.-Lay. Meteorol, 54, 1-27.

Davis, R. E., Hardy, J. P., Ni, W., et al. (1997). Variation of snow cover ablation in the boreal forest: a sensitivity study on the effects of conifer canopy. J Geophys. Res., 102(D24), 29 389-29 398.

de la Casiniere, A. C. (1974). Heat exchange over a melting snow surface. J. Glaciol., 13, 55-72.

Dery, S. J. and Yau, M. K. (2002). Large-scale mass balance effects of blowing snow and surface sublimation. J. Geophys. Res., 107(D23), 4679.

Dery, S. J., Taylor, P. A., and Xiao, J. (1998). The thermodynamic effects of sublimating blowing snow in the atmospheric boundary layer. Bound.-Lay. Meteorol., 89, 251-283.

Doorschot, J. (2002). Mass transport of drifting snow in high alpine environments. Ph.D. Thesis, Swiss Federal Institute of Technology ETHZ, Zürich.

Doorschot, J. and Lehning, M. (2002). Equilibrium saltation: mass fluxes, aerodynamic entrainment, and dependence on grain properties. Bound.-Lay. Meteorol., 104, 111-130.

Doorschot, J., Raderschall, N., and Lehning, M. (2001). Measurement and one-dimensional model calculations of snow transport over a mountain ridge. Ann. Glaciol., 32, 153-158.

Dozier, J. (1980). A clear sky spectral solar radiation model for snow-covered mountainous terrain. Water Resources Res., 16, 709-718.

Durand, Y., Brun, E., Merindol, L., et al. (1993). A meteorological estimation of relevant parameters for snow models. Ann. Glaciol., 18, 65-71.

Durand, Y., Guyomarc'h, G., and Merindol, L. (2001). Numerical experiments of wind transport over a mountainous instrumented site: I. Regional scale. Ann. Glaciol., 32, 187-194.

Dyunin, A. K., Kvon, Ya. D., Zhilin A. M., and Komorov, A. A. (1991). Effect of snow drifting on large-scale aridization. In Glaciers-Ocean-Atmosphere Interactions (ed. Kotlyakov, V. M., Ushakov, A., and Glasovsky, A.). IAHS Publication No. 208. Wallingford: IAHS Press, pp. 489-494.

Ebert, E. E. and Curry, J. A. (1993). An intermediate one-dimensional thermodynamic sea ice model for investigating ice-atmosphere interactions. J. Geophys. Res., 98(C6), 10 085-10 109.

Elder, K., Dozier, J., and Michaelsen, J. (1989). Spatial and temporal variation of net snow accumulation in a small alpine watershed. Emerald Lake basin, Sierra Nevada, California, U.S.A. Ann. Glaciol., 13, 56-63.

Essery, R. (1997). Modelling fluxes of momentum, sensible heat and latent heat over heterogeneous snow cover. Q. J. Roy. Meteorol. Soc., 123, 1867-1883.

Essery, R., Li, L. and Pomeroy, J. W. (1999). A distributed model of blowing snow over complex terrain. Hydrol. Process, 13(14-15), 2423-2438.

Essery, R. and Pomeroy, J. W. (2004). Vegetation and topographic control of wind-blown snow distributions in distributed and aggregated simulations for an Arctic tundra basin. J. Hydrometeorol., 5, 734-744.

Faria, D. A., Pomeroy, J. W., and Essery, R. L. H. (2000). Effect of covariance between ablation and snow water equivalent on depletion of snow-covered area in a forest. Hydrol. Process., 14(15), 2683-2695.

Fierz, C., Plüss, C., and Martin, E. (1997). Modelling the snow cover in complex alpine topography. Ann. Glaciol., 25, 312-316.

Fohn, P. M. B. (1973). Short term snow melt and ablation derived from heat- and mass-balance measurements. J. Glaciol., 12(65), 275-289.

Fohn, P. M. B. (1977). Representativeness of precipitation measurements in mountainous areas. In Proc. Joint Scientific Meeting on Mountain Meteorology and Biometeorology AMS, SGBB, SSG, Interlaken, Switzerland, 10-14 June 1976 (ed. Primault, B.). Geneva: Blanc et Wittwer, pp. 61-71.

Fohn, P. M. B. (1985). Besonderheiten des Schneeniederschlages. In Der Niederschlag in der Schweiz. Beitr. Geol. Schweiz - Hydrol., vol. 31, Bern: Kummerly und Frey, pp. 87-96.

Fohn, P. M. B. (1992). Climatic change, snow cover and avalanches. In Greenhouse-Impact on Cold-Climate Ecosystems and Landscape (ed. Boer, M. and Köster, E.). Catena supplement 22. Cremlingen-Destedt: Catena, pp. 11-21.

Föhn, P. and Hachler, P. (1978). Prevision de grosses avalanches au moyen d'un modele deterministe-statistique. In Comptes Rendues de la Deuxieme Rencontre Internationale sur la Neige et les Avalanches, Grenoble, France, 12-14 avril 1978. Grenoble: Association Nationale pour l'Etude de la Neige et des Avalanches (ANENA), pp. 151-165.

Gardiner, B. G. (1987). Solar radiation transmitted to the ground through cloud in relation to surface albedo. J. Geophys. Res., 92(D4), 4010-4018.

Garratt, J. R. (1992). The Atmospheric Boundary Layer. Cambridge: Cambridge University Press.

Gauer, P. (1998). Blowing and drifting snow in alpine terrain: Numerical simulation and related field measurements. Ann. Glaciol., 26, 174-178.

Gauer, P. (2001). Numerical modeling of blowing and drifting snow in Alpine terrain. J. Glaciol., 47(156), 97-110.

Grainger, M. E. and Lister, H. (1966). Wind speed, stability and eddy viscosity over melting ice surfaces. J. Glaciol., 6(43), 101-127.

Granger, R. J. and Male, D. H. (1978). Melting of a prairie snowpack. J. Appl. Meteorol., 17, 1833-1842.

Gray, D. M. (ed.). (1970). Handbook on the Principles of Hydrology. Ottawa: Canadian National Committee for the International Hydrological Decade.

Harding, R. J. (1986). Exchanges of energy and mass associated with a melting snow pack. In Modelling Snowmelt-Induced Processes (ed. Morris, E. M.). IAHS Publication No. 155. Wallingford: IAHS Press, pp. 3-15.

Harding, R. J. and Pomeroy, J. W. (1996). The energy balance of the winter boreal landscape. J. Climate, 9, 2778-2787.

Hardy, J. P., Davis, R. E., Jordan, R., et al. (1997a). Snow ablation modelling at the stand scale in a boreal jack pine forest. J. Geophys. Res., 102(D24), 29 39729406.

Hardy, J. P., Davis, R. E., Jordan, R., Li, X., and Woodcock, C. (1997b). Snow ablation modelling in conifer and deciduous stands of the boreal forest. Proc. Western Snow Conf., 65, 114-124.

Hedstrom, N. R. and Pomeroy, J. W. (1998). Accumulation of intercepted snow in the boreal forest: measurements and modelling. Hydrol. Process., 12, 16111625.

Heinemann, G. (1989). Über die Rauhigkeitslange z0 der Schneeoberflache des Filchner-Ronne Schelfeises. Polarforschung, 59, 17-24.

Hetherington, E. D. (1987). The importance of forests in the hydrological regime. Can. Bull. Fish. Aquatic Sci., 215, 179-211.

Inoue, J. (1989). Surface drag over the snow surface of the Antarctic Plateau. 1. Factors controlling surface drag over the katabatic wind region. J. Geophys. Res., 94(D2), 2207-2217.

Iqbal, M. (1983). An Introduction to Solar Radiation. Toronto: Academic Press.

Joffre, S. M. (1982). Momentum and heat transfers in the surface layer over a frozen sea. Bound.-Lay. Meteorol, 24, 211-229.

Jones, H. G. (1987). Chemical dynamics of snowcover and snowmelt in a boreal forest. In Seasonal Snowcovers: Physics, Chemistry, Hydrology (ed. Jones, H. G. and Orville-Thomas, W. J.). NATO ASI Series C, vol. 211. Dordrecht: Reidel Publishing, pp. 531-574.

Jones, H. G., Pomeroy, J. W., Walker, D. A., and Hoham, R. (eds.). (2001). Snow Ecology: an Interdisciplinary Examination of Snow-Covered Ecosystems. Cambridge: Cambridge University Press.

Jordan, R. E., Andreas, E. L., Fairall, C. W., et al. (2003). Modeling surface exchange and heat transfer for the shallow snow cover at SHEBA. In Seventh Conference on Polar Meteorology and Oceanography, Hyannis, MA (CD-ROM of preprints). Washington, DC: American Meteorological Society.

Jordan, R. E., Andreas, E. L., and Makshtas, A. S. (1999). The heat-budget of snow-covered sea ice at North-pole 4. J. Geophys. Res., 104(D4), 7785-7806.

Key, J. R., Silcox, R. A., and Stone, R. S. (1996). Evaluation of surface radiative flux parameterizations for use in sea ice models. J. Geophys. Res., 101(C2), 38393849.

Kind, R. J. 1992. One-dimensional aeolian suspension above beds of loose particles - a new concentration-profile equation. Atmos. Environ., 26A, 927-931.

King, J. C. 1990. Some measurements of turbulence over an Antarctic ice shelf. Q. J. Roy. Meteor. Soc., 116, 379-400.

King, J. C. and Anderson, P. S. (1994). Heat and water vapour fluxes and scalar roughness lengths over an Antarctic ice shelf. Bound.-Lay. Meteorol., 69, 101-121.

King, J. C., Anderson, P. S., Smith, M. C., and Mobbs, S. D. (1996). The surface energy and mass balance at Halley, Antarctica, during winter. J. Geophys. Res., 101(D14), 19119-19128.

King, J. C. and Connolley, W. M. (1997). Validataion of the surface energy balance over the Antarctic ice sheets in the U.K. Meteorological Office Unified Climate Model. J. Climate, 10, 1273-1287.

Kirnbauer, R., Bloschl, G., and Gutknecht, D. (1994). Entering the era of distributed snow models. Nordic Hydrol, 25, 1-24.

Kondo, J. and Yamazawa, H. (1986). Bulk transfer coefficient over a snow surface. Bound.-Lay. Meteorol., 34, 123-135.

Konig, G. (1985). Roughness length of an Antarctic ice shelf. Polarforschung, 55, 27-32.

Konig-Langlo, G. and Augstein, E. (1994). Parameterization of the downward longwave radiation at the Earth's surface in polar regions. Meteorol. Z, 3, 343-347.

Konstantinov, A. R. (1966). Isparenie v Prirode. Leningrad: Gidrometeoizdat. Published 1968 as Evaporation in Nature. (English translation by Israel Programme for Scientific Translation, Jerusalem.)

Konzelmann, T., van de Wal, R., Greuell, W., et al. (1994). Parameterization of global and longwave incoming radiation for the Greenland ice sheet. Global Planet. Change, 9, 143-164.

Kucherov, N. V. and Sternzat, M. S. (1959). The apparatus and method of investigations at stations North Pole 4 and North Pole 5. Trudy. Arkt. Antarkt. Nauchno-Issl. Inst., 226, 5-18. (In Russian; English translation available from the CRREL Library.)

Kuz'min, P. P. (1960). Formirovanie Snezhnogo Pokrova I Metody Opredeleniya Snegozapasov, Leningrad. Published 1963 as Snow Cover and Snow Reserves. Washington, DC: National Science Foundation. (English translation by Israel Programme for Scientific Translation, Jerusalem.)

Lee, L. W. (1975). Sublimation of snow in a turbulent atmosphere. Ph.D. Thesis, University of Wyoming, Laramie, WY.

Lehning, M., Bartelt, P., Bethke, S., et al. (2004). Review of SNOWPACK and Alpine3D applications. In Snow Engineering, vol. V. (ed. Bartelt, P., Adams, E. E., Christen, M., Sack, R. L., and Sato, A.). Leiden: Balkema Publishers, pp. 299-307.

Lehning, M., Bartelt, P., Brown, B., and Fierz, C. (2002a). A physical SNOWPACK model for the Swiss avalanche warning; Part III: Meteorological forcing, thin layer formation and evaluation. Cold Reg. Sci. Technol., 35(3), 169-184.

Lehning, M., Bartelt, P., Brown, B., Fierz, C., and Satyawali, P. (2002b). A physical

SNOWPACK model for the Swiss avalanche warning; Part II: Snow microstructure. Cold Reg. Sci. Technol., 35(3), 147-167.

Li, L. and Pomeroy, J. W. (1997a). Estimates of threshold wind speeds for snow transport using meteorological data. J. Appl. Meteorol., 36, 205-213.

Li, L. and Pomeroy, J. W. (1997b). Probability of occurrence of blowing snow. J. Geophys. Res., 102(D18), 21 955-21 964.

Lindsay, R. W. (1998). Temporal variability of the energy balance of thick Arctic pack ice. J. Climate, 11, 313-333.

Liston, G. E. (1995). Local advection of momentum, heat and moisture during the melt of patchy snow covers. J. Appl. Meteorol., 34, 1705-1715.

Liston, G. E. and Sturm, M. (1998). A snow-transport model for complex terrain. J. Glaciol., 44(148), 498-516.

Lundberg, A., Calder, I., and Harding, R. (1998). Evaporation of intercepted snow: measurements and modelling. J. Hydrol, 206, 151-163.

Lundberg, A. and Halldin, S. (1994). Evaporation of intercepted snow - an analysis of governing factors. Water Resources Res., 30, 2587-2598.

Male, D. H. and Gray, D. M. (1975). Problems in developing a physically-based snowmelt model. Can. J. Civil Eng., 2, 474-488.

Male, D. H. and Gray, D. M. (1981). Snowcover ablation and runoff. In Handbook of Snow: Principles, Processes, Management and Use (ed. Gray, D. M. and Male, D. H.). Toronto: Pergamon Press, pp. 360-436.

Marks, D. and Dozier, J. (1992). Climate and energy exchange at the snow surface in the Alpine region of the Sierra Nevada. 2. Snow cover energy balance. Water Resources Res., 28, 3042-3054.

Marsh, P. and Pomeroy, J. W. (1996). Meltwater fluxes at an Arctic forest tundra site. Hydrol. Process., 10, 1383-1400.

Marsh, P., Pomeroy, J. W., and Neumann, N. (1997). Sensible heat flux and local advection over a heterogeneous landscape at an Arctic tundra site during snowmelt. Ann. Glaciol., 25, 132-136.

Marshunova, M. S. and Mishin, A. A. (1994). Handbook of the radiation regime of the Arctic Basin (Results from the drift stations). Technical Report APL-UW TR 9413. Seattle, WA: Applied Physics Laboratory, University of Washington.

Martin, E., Brun, E., and Durand, Y. (1994). Sensitivity of the French Alps snow cover to the variation of climatic variables. Ann. Geophys., 12, 469-477.

Martin, E. and Lejeune, Y. (1997). Investigations on turbulent fluxes above the snow surface. Ann. Glaciol., 26, 179-183.

Marty, C. (2000). Surface radiation, cloud forcing and greenhouse effect in the Alps. Ph.D. Thesis, Swiss Federal Institute of Technology ETHZ, Zürich.

Maykut, G. A. (1982). Large-scale heat exchange and ice production in the central Arctic. J. Geophys. Res., 87(C10), 7971-7984.

Metcalfe, R. A. and Buttle J. M. (1995). Controls of canopy structure on snowmelt rates in the boreal forest. Proc. Eastern Snow Conf., 52, 249-257.

Metcalfe, R. A. and Buttle, J. M. (1998). A statistical model of spatially distributed snowmelt rates in a boreal forest basin. Hydrol. Process., 12, 1701-1722.

Michaux, J. L., Naaim-Bouvet, F., and Naaim, M. (2001). Drifting snow studies over a mountainous instrumented site: measurements and numerical model. Ann. Glaciol., 32, 175-181.

Moore, R. D. and Owens, I. F. (1984). Controls on advective snowmelt in a maritime alpine basin. J. Appl. Meteorol., 23, 135-142.

Morris, E. M. (1989). Turbulent transfer over snow and ice. J. Hydrol., 105, 205-223.

Morris, E. M., Anderson, P. S., Bader, H.-P., Weilenman, P., and Blight, C. (1994).

Modelling mass and energy exchange over polar snow using the DAISY model. In Snow and Ice Covers: Interactions with the Atmosphere and Ecosystems (ed. Jones, H. G., Davies, T. D., Ohmura, A., and Morris, E. M.). IAHS Publication No. 223. Wallingford: IAHS Press, pp. 53-60.

Nakai, Y., Kitahara, H., Sakamoto, T., Saito, T., and Terajima, T. (1993). Evaporation of snow intercepted by forest canopies. J. Jpn. Forest Soc., 75, 191-200.

Nakai, Y., Sakamoto, T., Terajima, T., Kitahara, H., and Saito, T. (1994). Snow interception by forest canopies: weighing a conifer tree with meteorological observation and analysis with Penman-Monteith formula. In Snow and Ice Covers: Interactions with the Atmosphere and Ecosystems (ed. Jones, H. G., Davies, T. D. Ohmura, A., and Morris, E. M.). IAHS Publication No. 223. Wallingford: IAHS Press, pp. 227-236.

Nakai, Y., Sakamoto, T., Terajima, T., Kitamura, K., and Shirai, T. (1999). Energy balance above a boreal coniferous forest: a difference in turbulent fluxes between snow-covered and snow-free canopies. Hydrol. Process., 13, 515-529.

National Snow and Ice Data Center (NSIDC). (1996). Arctic Ocean Snow and

Meteorological Observations from Drifting Stations: 1937,1950-1991, CD-ROM Version 1.0. Boulder, CO: University of Colorado.

Nazintsev, Yu. L. (1963). On the role of thermal processes in sea ice melting and in the transformation of the relief of multiyear ice floes in the central Arctic (in Russian). Prob. Arkt. Antarkt., 12, 69-75. (In Russian; English translation available from the CRREL Library).

Nazintsev, Yu. L. (1964). Thermal balance of the surface of the perennial ice cover in the central Arctic. Trudy, Arkt. Antarkt. Nauchno-Issl. Inst., 267, 110-126. (In Russian; English translation available from the CRREL Library).

Neumann, N. and Marsh, P. (1998). Local advection of sensible heat in the snowmelt landscape of Arctic tundra. Hydrol. Process., 12, 1547-1560.

Ni, W., Li, X., Woodstock, C. E., Roujean, J-L., and Davis, R. E. (1997). Transmission of solar radiation in boreal conifer forests: measurements and models. J. Geophys. Res., 102(D24), 29 555-29 566.

Ohmura, A. 2001. Physical basis for the temperature-based melt-index method. J. Appl. Meteorol., 40, 753-761.

Oke, T. R. (1987). Boundary Layer Climates, 2nd edn. London: Routledge.

Olyphant, G. and Isard, S. (1988). The role of advection in the energy balance of late-lying snowfields: Niwot Ridge, Front Range, Colorado. Water Resources Res., 24, 1962-1968.

O'Neill, A. D. J. and Gray, D. M. (1973). Spatial and temporal variations of the albedo of a prairie snowpack. In The Role of Snow and Ice in Hydrology: Proc., Banff Symposium, vol. 1. Geneva-Budapest-Paris: UNESCO-WMO-IAHS, pp. 176-186.

Owen, P. R. (1964). Saltation of uniform grains in air. J. Fluid Mech., 20, 225-242.

Parviainen, J. and Pomeroy, J. W. (2000). Multiple-scale modelling of forest snow sublimation: initial findings. Hydrol. Process., 14(15), 2669-2681.

Perovich, D. K., Grenfell, T. C., Light, B., and Hobbs, P. V. (2002). Seasonal evolution of the albedo of multiyear Arctic sea ice. J. Geophys. Res., 107(C10), 8044, doi:10.1029/2000JC000438.

Persson, P. O. G., Fairall, C. W., Andreas, E. L., Guest, P. S., and Perovich, D. K. (2002). Measurements near the Atmospheric Surface Flux Group tower at SHEBA: near-surface conditions and surface energy budget. J. Geophys. Res., 107(C10), 8043, doi:10.1029/2000JC000705.

Plüss, C. (1997). The Energy Balance over an Alpine Snowcover - Point Measurements and Areal Distribution. Zürcher Geographische Schriften (ZGS), Heft vol. 65. Zürich: Swiss Federal Institute of Technology ETHZ.

Plüss, C. and Ohmura, A. (1997). Longwave radiation on snow-covered mountainous surfaces. J. Appl. Meteorol., 36, 818-824.

Poggi, A. (1976). Heat balance in the ablation area of the Ampere Glacier (Kerguelen Islands). J. Appl. Meteorol., 16,48-55.

Pomeroy, J. W. (1989). A process-based model of snow drifting. Ann. Glaciol., 13, 237-240.

Pomeroy, J. W. (1991). Transport and sublimation of snow in wind-scoured alpine terrain. In Snow, Hydrology and Forests in High Alpine Areas (ed. Bergmann, H., Lang, H., Frey, W., Issler, D., and Salm, B.). IAHS Publication No. 205. Wallingford: IAHS Press, pp. 131-140.

Pomeroy, J. W., Davies, T. D., Jones, H. G., et al. (1999a). Transformations of snow chemistry in the boreal forest: accumulation and volatilization. Hydrol. Process., 13, 2257-2273.

Pomeroy, J. W. and Dion, K. (1996). Winter radiation extinction and reflection in a boreal pine canopy: measurements and modelling. Hydrol. Process., 10 1591-1608.

Pomeroy, J. W. and Essery, R. (1999). Turbulent fluxes during blowing snow: field tests of model sublimation predictions. Hydrol. Process., 13, 2963-2975.

Pomeroy, J. W., Essery, R. L. H., Gray, D. M., et al. (1999b). Modelling snow-atmosphere interactions in cold continental environments. In Interactions Between the Cryosphere, Climate and Greenhouse Gases (ed. Tranter, M., Armstrong, R., Brun, E., et al.). IAHS Publication No. 256. Wallingford: IAHS Press, pp. 91-101.

Pomeroy, J. W. and Granger, R. J. (1997). Sustainability of the western Canadian boreal forest under changing hydrological conditions -1 - Snow accumulation and ablation. In Sustainability of Water Resources under Increasing Uncertainty (ed. Rosjberg, D., Boutayeb, N., Gustard, A., Kundzewicz, Z., and Rasmussen, P.). IAHS Publication No. 240. Wallingford: IAHS Press, pp. 237-242.

Pomeroy, J. W. and Gray, D. M. (1990). Saltation of snow. Water Resources Res., 26(7), 1583-1594.

Pomeroy, J. W. and Gray, D. M. (1995). Snowcover Accumulation, Relocation and

Management. NHRI Science Report No. 7. Saskatoon: National Hydrology Research Institute.

Pomeroy, J. W., Gray, D. M., and Landine, P. G. (1993). The prairie blowing snow model: characteristics, validation, operation. J. Hydrol., 144, 165-192.

Pomeroy, J. W., Gray, D. M., Shook, K. R., et al. (1998b). An evaluation of snow accumulation and ablation processes for land surface modelling. Hydrol. Process., 12(15), 2339-2367.

Pomeroy, J. W., Hedstrom, N., and Parviainen, J. (1999c). The snow mass balance of Wolf Creek. In Wolf Creek Research Basin: Hydrology, Ecology, Environment (ed. Pomeroy, J. and Granger, R.). Saskatoon: National Water Research Institute, Minister of Environment, pp. 15-30.

Pomeroy, J. W. and Li, L. (2000). Prairie and Arctic areal snow cover mass balance using a blowing snow model. J. Geophys. Res., 105(D21), 26 619-26 634.

Pomeroy, J. W. and Male, D. H. (l992). Steady-state suspension of snow. J. Hydrol, 136, 275-301.

Pomeroy, J. W., Marsh, P., and Gray, D. M. (1997). Application of a distributed blowing snow model to the Arctic. Hydrol. Process., 11, 1451-1464.

Pomeroy, J. W., Parviainen, J., Hedstrom, N., and Gray, D. M. (1998a). Coupled modelling of forest snow interception and sublimation. Hydrol. Process., 12, 2317-2337.

Pomeroy, J. W. and Schmidt, R. A. (1993). The use of fractal geometry in modelling intercepted snow accumulation and sublimation. Proc. Eastern Snow Conf., 50, 1-10.

Raderschall, N. (1999). Statistische Uebertragung von Modelldaten eines Numerischen Wettervorhersagemodells auf Alpine Standorte. Diplomarbeit des Meteorologischen Instituts der Rheinischen Friedrich-Wilhelms-Universitaet Bonn, unpublished.

Radionov, V. F., Bryazgin, N. N., and Aleksandrov, E. I. (1996). The Snow Cover of the Arctic Basin. St. Petersburg: Gidrometeoizdat. (In Russian; English translation available as: Radionov, V. F., Bryazgin, N. N., and Aleksandrov, E. I. (1997). The Snow Cover of the Arctic Basin. Technical Report APL-UW TR 9701, Applied Physics Laboratory, University of Washington, Seattle.)

Schmidt, R. A. (1972). Sublimation of Wind-transported Snow-A Model. USDA Forest Service Research Paper RM-90. Fort Collins, CO: Rocky Mountain Forest and Range Experiment Station.

Schmidt, R. A. (1991). Sublimation of snow intercepted by an artificial conifer. Agric. Forest Meteorol., 54, 1-27.

Schmidt, R. A. and Gluns, D. R. (1991). Snowfall interception on branches of three conifer species. Can. J. Forest Res., 21, 1262-1269.

Shine, K. P. (1984). Parametrization of the shortwave flux over high albedo surfaces as a function of cloud thickness and surface albedo. Q. J. Roy. Meteorol. Soc., 110, 747-764.

Shook, K. (1993). Fractal geometry of snowpacks during ablation. M.Sc. Thesis, University of Saskatchewan, Saskatoon.

Shook, K. (1995). Simulation of the ablation of prairie snowcovers. Ph.D. Thesis, University of Saskatchewan, Saskatoon.

Shook, K. and Gray, D. M. (1994). Determining the snow water equivalent of shallow prairie snowcovers. Proc. Eastern Snow Conf., 51, 89-95.

Shook, K. and Gray, D. M. (1996). Small scale spatial structure of shallow snowcovers. Hydrol. Process., 10, 1283-1292.

Shook, K. and Gray, D. M. (1997). Snowmelt resulting from advection. Hydrol. Process., 11, 1725-1736.

Smeets, C. J. P. P., Duynkerke, P. G., and Vugts, H. F. (1998). Observed wind profiles and turbulence fluxes over an ice surface with changing surface roughness. Bound.-Lay. Meteorol., 92, 101-123.

Steppuhn, H. (1981). Snow and agriculture. In Handbook of Snow: Principles, Processes, Management and Use (ed. Gray, D. M. and Male, D. H.). Toronto: Pergamon Press, pp. 60-125.

Steppuhn, H. and Dyck, G. E. (1974). Estimating true basin snowcover. In Advanced Concepts in the Technical Study of Snow and Ice Resources. Interdisciplinary Symposium. Washington, DC: US National Academy of Sciences, pp. 314-328.

Stull, R. B. (1988). An Introduction to Boundary Layer Meteorology. Dordrecht: Kluwer Academic Publishers.

Sturm, M. (1992). Snow distribution and heat flow in the taiga. Arctic Alpine Res., 24(2), 145-152.

Sturm, M., Holmgren, J., Konig, M., and Morris, K. (1997). The thermal conductivity of seasonal snow. J. Glaciol., 43, 26-41.

Sturm, M., Holmgren, J., and Liston, G. E. (1995). A seasonal snow cover classification system for local to global applications. J. Climate, 8, 1261-1283.

Sturm, M., Perovich, D. K., and Holmgren, J. (2002). Thermal conductivity and heat transfer through the snow on the ice of the Beaufort Sea. J. Geophys. Res., 107(C10), 8045, doi:10.1029/2000JC000466.

Sverdrup, H. H. (1936). The eddy conductivity of the air over a smooth snowfield. Geophys. Publ., 11(7), 5-49.

Tabler, R. D. (1980). Self similarity of wind profiles in blowing snow allows outdoor modelling. J. Glaciol., 26(94), 421-434.

Tabler, R. D. and Schmidt, R. A. (1986). Snow erosion, transport and deposition. In Proc. Symposium on Snow Management for Agriculture (ed. Steppuhn, H. and Nicholaichuk, W.). Great Plains Agricultural Council Publication No. 120. Lincoln: University of Nebraska, pp. 12-58.

Thomas, G. and Rowntree, P. R. (1992). The boreal forest and climate. Q. J. Roy. Meteorol. Soc., 118, 469-497.

Thorpe, A. D. and Mason, B. J. (1966). The evaporation of ice spheres and ice crystals. Br. J. Appl. Phys., 17, 541-548.

Uttal, T., Curry, J. A., McPhee, M. G., et al. (2002). Surface heat budget of the Arctic Ocean. Bull. Amer. Meteor. Soc, 83(2), 255-275.

Van den Broeke, M. R. (1997). Structure and diurnal variation of the atmospheric boundary layer over a mid-latitude glacier in summer. Bound.-Lay. Meteorol., 83, 183-205.

Varley, M. J., Beven, K. J., and Oliver, H. R. 1996. Modelling solar radiation in steeply sloping terrain. J. Climate, 16, 93-104.

Webb, E. K. (1970). Profile relationships: the log-linear range and extension to strong stability. Q. J. Roy. Meteorol. Soc., 96, 67-90.

Weisman, R. W. (1977). Snowmelt: a two-dimensional turbulent diffusion model. Water Resources Res., 13(2), 337-342.

Woo, M-K. and Steer, P. (1986). Monte Carlo simulation of snow depth in a forest. Water Resources Res., 22(6), 864-868.

Yamazaki, T., Fukabori, K., and Kondo, J. (1996). Albedo of forest with crown snow. Seppyo, J. Jpn. Soc. Snow Ice, 58. 11-18 (in Japanese with English summary).

Yang, D., Goodison, B. E., Metcalfe, J. R., et al. (1995). Accuracy of Tretyakov precipitation gauge: result of WMO intercomparison. Proc. Eastern Snow Conf., 52, 95-106.

Zhao, L., Gray, D. M., and Male, D. H. (1997). Numerical analysis of simultaneous heat and mass transfer during infiltration into frozen ground. J. Hydrol, 200, 345-363.

Was this article helpful?

0 0
Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

Get My Free Ebook

Post a comment