Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

VARIATION IN INSULATING EFFECT OF SNOW COVER IN CENTRAL YAKUTIA

Varlamov Stepan Prokopievich (1), Skachkov Yury Borisovich (1), Skryabin Pavel Nickolaevich (1)

Snow cover is a seasonal phenomenon whose properties, structure and depth vary in time and space. It is one of the basic factors affecting the ground temperature regime. Investigations of the insulating effect of the snow cover have been conducted in the vicinity of Yakutsk since 1981. The research sites were established in small-valley and slope terrain types (Chabyda station), and in low-terrace and flood-plain terrain types in the Lena River valley. Data from long-term observations at the Chabyda station permit quantitative estimation of the warming effect of snow (presented as the temperature difference between the surface cover and the air) in relation to the thermal regime of air, the dynamics of snow accumulation, characteristics of the surface cover, lithology, and soil moisture. A long-term experimental investigation allowed us to evaluate the variations in the influence of snow cover on the ground temperature regime across stows of different terrain types. The warming effect of the snow cover has been found to vary across stows, on seasonal average, from 2.5 to 15.4ºC or by 1.7-9.4ºC every 10 cm of distance. The influence of interannual variations in snow parameters and snow accumulation rates on the mean annual ground temperature is more significant in small-valley, low-terrace and partially in slope terrain types. No or very little effect of these variations is observed at the localities where water-bearing taliks or suprapermafrost water within the seasonally thawed layer exist, as well as on dry sand slopes with deep seasonal thawing. Due to the decreased snow depth in the first half of winter and the reduced insulating effect of snow the mean annual ground temperature in cold stows has not increased despite of the warming climate of the last 20 years.

Submittal Information

Name : Date :
    Varlamov Stepan Prokopievich
    21-May-01-15:42:09
Organization : Theme :
    Melnikov Permafrost Institute, Siberian Branch, Russian Academy of Sciences
    Theme 2
Address : Presentation :
    Yakutsk-10, Russia 677010
    Poster or oral
Country : Abstract ID :
    Russia
    T2VSP21May01154209
Phone : Fax :
    +8-4112-444476
    +8-4112-444476
E-mail :
    skachkov@mpi.ysn.ru