INFLUENCE OF ATMOSPHERIC PRECIPITATION ON PERENNIAL TEMPERATURE DYNAMICS
Konstantinov, Pavel (1)
(1) no
Results of observations of thermal conditions of upper permafrost around Central Yakutia GAME station for the period of 1996-2003 years are given in this paper.
Observation area is situated in Central Yakutia (Eastern Siberia, Russia) between Lena and Kenkeme rivers, 25 km north of Yakutsk, in taiga with continuous permafrost.
For the period of observations there were no considerable interannual air temperature changes. However, significant interannual jumps of precipitation amount both for the year total amount and for the seasons one. That caused the interannual change of pre-winter soil moisture content (in 2-3 times) and snow-cover thickness (in 2-4 times).
It was found out that increase of pre-winter moisture content (average value of gravimetric moisture for the whole section of the active layer) by 10% led to prolongation of freezing period in average by 30-40 days for silty soils and by 20-30 days sandy soils. Prolongation of freezing period of the active layer by a month leads to increase of average annual soil temperature and upper permafrost in average by 0.80C for sands and by 10C for silty loams.
For the period of 1996-2003 changes of average annual temperature of upper permafrost at natural landscapes were 1,2-1,80C. The biggest interannual changes of average soil temperature (to 3,20C) were noted at the areas of larch forests cuttings, which create proper conditions
for the biggest interannual variations of the active layer moisture content.
Short periods (not longer then 3 years) of temperature increase in upper permafrost take turns with the same periods of its decrease according to short-period nature of interannual changes of soil moisture content and snow-cover thickness in 1996-2003. At the same time for the last 20 years in taiga landscapes around Yakutsk there are no systematic long-period (10 years and more) changes of average annual temperature of upper permafrost.
Thus the achieved results show that stable or unstable thermal conditions of permafrost of Central Yakutia in future depend considerably on long-period dynamics of atmosphere moistening.
Submittal Information
Name :
Date :
Konstantinov, Pavel
30-Jul-04-09:49:18
Organization :
Theme :
Permafrost Institute
Theme 1
Address :
Presentation :
Merzlotnaya,1, Permafrost Institute, Yakutsk, 677010