對流雲的一維數值模擬

胡仲英

Abstract

　　In this thesis the steady-state one dimensional cumulus model dy Weinstein-Davis (1968) is further examined. It has been found that the result of cloud water content calculated by that model does not satisfy the cloud microphysical process, namely, there is an increase of cloud water content converted from hydrometeor water by negative collection process when the terminal velocity of hydrometeor water is greater than updraft velocity. The model is modified to eliminate such unreal increase of cloud water content. The modified model is applied to calculate all variables in the cloud layer and rainfall amount at cloud base, Finally, the modified model has been applied to I.G.Y. soundings to determine the seeding potential in terms of cloud growth and precipitation production. It has been found that wheu the atmosphere is conditionally unstable and with sufficient strength of updraft current, the middle size cloud should be used for testing, because artificial ice nuclei in these clouds can trigger freezing which would never have occurred naturally.