Snow, Snow Properties, & Nivean Environment

Refer to Winter, An Ecological Handbook by J. Halfpenny and R.D. Ozanne




1. How many types of snow are generally classified?





2. Look at Figure 26, the graph. What two main characteristics determine what specific type of snow will be formed?





3. Describe: columns, needles, and spatial dendrites.







4. What is graupel?




5. What factors cause snow on the ground to change?








6. Outline the metamorphosis of snow on the ground:





7. Examine Figure 28, the classification system of Magano and Lee.

How many basic categories are used and how many total categories are defined?



8. Describe the categories of snow in the Sommerfield and LaChapelle system:





9. Describe ET and TG forms of snow metamorphosis:









10. Describe sugar snow:





11. Outline the process of firnification:







12. How does the classification of Colbeck define categories of snow? Fig. 30






13. Describe these surface-generated features: rime forst, hoar frost, needle ice, water ice, melt-freeze layers, crust, and runoff channels:















14. Describe the factors involved in the following snow properties, that is, describe what each is and how it is measured:











            Thermal Conductivity




15. Use Table 6. How is the density of snow influenced by other factors?





16. Use Table 7. Compare and contrast the thermal conductivity of snow to that of other substances:




17. Use Figure 34. How does the thermal conductivity relate to snow density?




18. How does depth hoar form?





19. Describe a temperature profile. How does the profile change over the course of a day?








20. How can the isothermal time be harmful to small mammals?

21. Describe these circumstances related to the snowpack:











                        What is scattering and absorption?






22. What are the three levels of the nivean environment?




23. Give the names and descriptions of the three groups of organisms with respect to snow as classified by Formozov: Give some examples.









24. How does footload relate to adaptation for winter living?




25. How do humans decrease footload for travel on snow?



26. Describe the snow-coping index as developed by Telfer and Kelsall. Why might this be a more accurate picture of an animal’s adaptations to winter?



27. What are six behavioral traits that relate to the snow-coping index?



28. Use Table 10. Which animals have the best snow coping index value?

29. What are each of these and how do they relate to the survival of organism in the subnivean environment?


            fall critical period


            autumnal thermal overturn


            hiemal threshold




biological clock



winter hardening


overwinter period


ice lenses


spring period


vernal overturn




isothermal point




spring runoff


needle ice




30. Discuss how effective snow is at stabilizing the temperature at ground level:





            How is   T determined?



            What is the snow index and how is the thermal index different?


31. How does snow affect the light passing through it?




32. What are spring ephemerals?




33. How do plants make food (photosynthesize) under the snow?




34. Why are plants critical to the animals in the subnivean environment?




35. What is the photoperiod of a plant?




36. Discuss how the snowpack relates to the movement of carbon dioxide gas:




37. What is snow mold?




38. How do ventilation shafts affect the carbon dioxide level it the subnivean environment?




39. Use Fig. 52, the food web. What are some other animals that could be part of this web?




How many mice would be found in food chain compared to weasels? Why?