Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

The temporal variation of precipitable water in Yakutsuk, eastern Siberia

Nobuhiko ENDO (1), Tetsuya HIYAMA (2), Tetsuo OHATA (3), Tetsuzo YASUNARI (4)

The water vapor is most abundant greenhouse gas over the earth, and to clarify the water cycle in the cold region is important for adequate understanding of climate and global change. The GAME-Siberia IOP was conducted to investigate the processes of the water and energy cycle around Yakutsk in eastern Siberia from April to September 2000. Enhanced upper-air observations were made at the four synoptic times in a day from April to June and it allowed us to examine the diurnal variation of the precipitable water and planetary boundary layer. The routine upper-air observation data also provided from Central Aerological Observatory of Russia for the IOP period. Seasonal cycle of the precipitable water is evidently large and the water vapor is most abundant due to the increase of the surface evapotranspiration and the increase of water vapor transport from June to August. It is frequently observed that the fluctuation of the precipitable water and wind direction with a period of about 2-3 days in summer. These fluctuations may be related to passage of the cyclone system because the polar frontal zone tends to exist over the Siberian region in this season. Through the investigation of the enhanced upper-air observation data it is found that the precipitable water is less in the morning (00UTC) and tends to increase until the evening (12UTC) or the mid-night (18UTC) in the monthly average diurnal cycle. The precipitable water in the nighttime is larger than its in the morning is also obtained from the examination of the routine upper-air observation data from 1975 to 1993 when the radiosonde was launched at the three synoptic times (00,12 and 18UTC). Although the surface evapotanspiration generally active during the daytime, the surface water vapor flux is very small or negative in the nighttime. A contribution of the regional and larger scale water vapor transport processes to the amount of precipitable water is larger in the nighttime are discussed.

Submittal Information

Name : Date :
    Nobuhiko ENDO
    31-May-01-15:30:36
Organization : Theme :
    Frontier Research System for Global Change
    Theme 2
Address : Presentation :
    c/o NIED, 3-1 Tennoudai, Tsukuba, Ibaraki
    Only poster
Country : Abstract ID :
    Japan
    T2NE31May01153036
Phone : Fax :
    +81-298-52-1907
    +81-298-52-1899
E-mail :
    nobu@bosai.go.jp