Abstracts for the 6th International GAME Conf.

3-5 December 2004

Kyoto Japan

Cloud formation and fractionation of stable isotope of water within Aritficial Cloud Experimental System

Y. Fujiyoshi (1), S. Nakajima (2), S. Yamagata (3)

By making use of Artificial Cloud Experimental System (ACES) in a long vertical shaft (430 m) of an iron mine in Kamaishi, Iwate Prefecture, we have examined the fundamental processes related to the formation of cloud. Two electric fans sucked air at the top of the shaft to produce updraft velocity ranging from 0.5 to 2 m/s. We conducted basic measurements of air temperature profiles, updraft air velocity, size distribution of cloud droplets and aerosol particles, etc. We were firstly able to detect the very stable layer near the cloud base. Vertical profiles of air temperature above and below it showed moist adiabatic and dry adiabatic lapse rate, respectively. There existed the maximum supersaturation of relative humidity in the layer whose depth was only a few tens meter. The cloud-physical processes that occur in the layer decide the size distribution of cloud droplets, thus, microphysical and radiative properties of a cloud. Recent improvements of experimental conditions allowed us to study the indirect effect of aerosol particles. In addition to the studies of cloud physics, we measured the stable isotope of water vapor below cloud base and of cloud water at several levels of a cloud. We were firstly able to confirm the Rayleigh distillation process with a closed system. The results of experiments are being used to verify our detailed micro-physical model and parameterization schemes.

Submittal Information

Name : Date :
    Yasushi Fujiyoshi
    09-Aug-04-19:42:10
Organization : Theme :
    FRCGC/Hokakido University
    Theme 2
Address : Presentation :
    N19W8 Sapporo 060-0819
    Poster or oral
Country : Abstract ID :
    JAPAN
    T2YF09Aug04194210
Phone : Fax :
    011-706-5491
    011-706-5491
E-mail :
    fujiyo@lowtem.hokudai.ac.jp