(1) Frontier Observational Research System for Global Change
(2) Institute of Low Temperature Science Hokkaido Univ.
(3) Institute of Low Temperature Science Hokkaido Univ./Frontier Observational Research System for Global Change
Micro-meteorological observations have been carried out in Siberia tundra region in order to better understand the energy and water cycle over permafrost zone. These tundra regions have a unique water cycle due to the existence of frozen ground and tundra vegetation. These energy and water fluxes are also dependent on the atmospheric conditions. In this paper, the characteristics on evaporation and soil moisture at the tundra surface are reported.
The observation site is located about 7km south from Tiksi (7135f N, 12846f E) The observation tower with 10m high was set up, and the instruments were installed onto the tower. The Bowen ratio method was used to calculate the sensible heat flux and latent heat flux at the summer period (JJA (June, July and August)) in 1999 and 2000.
The average air temperature at the summer period (JJA) in 1999 and 2000 were 8.4C and 6.1C respectively. The average net radiation in the JJA 1999 and 2000 were 118 Wm-2 and 101Wm-2. Air temperature and net radiation in JJA 1999 were bigger than JJA 2000. The total precipitation of JJA in 1999 and 2000 were 98mm and 161mm. The precipitation in 1999 was almost half in 2000. In spite of difference of the climate condition, the total evaporation of JJA in 1999 and 2000 became respectively equal 167mm and 156mm. The possible evaporation of JJA in 1999 and 2000 were 253mm and 178mm. Evaporation efficiency defined at the ratio of possible evaporation and real evaporation in 1999 and 2000 were 0.66 and 0.88 respectively. And soil moisture saturation ratio in 1999 and 2000 were 0.68 and 0.94 respectively, the surface soil moisture condition was almost saturation in 2000. Though the net radiation is big in 1999, the evaporation efficiency is small, because the soil moisture saturation ratio is small. On the other hand in 2000, the net radiation is small, the evaporation efficiency is big, because the soil moisture saturation ratio is big. The Evaporation in 1999 and 2000 were become nearly equal.
Submittal Information
Name :
Date :
Hironori YABUKI
15-May-01-10:59:21
Organization :
Theme :
Frontier Observational Research System for Global Change
