Hygrokinematical Analysis and It's Application in Weather Forecasting(One proposed method to abridge the cloud physics and synoptics)

[摘要] The meteorology in the border area between the cloud physics and synoptics, and the method how to combine both knowledges in the technics of weather forecasting are all hitherto left untouched.Using the idea proposed by Ligda about the aftereffect of a thunderstorm, the author attempted to construct a technic which was named “ Hygrokinematical analysis” by Ligda. This technic starts with the assumptions that the vertically developed cloud will disintegrate to stratiform clouds of several layers. The clouds will flow away by the winds at each level maintaining it's cloud form and high liquid water content as far it takes the way of upsloping. The procedure of the analysis used in this paper are as follows: 1) identify the storm groups from the hourly precipitation report and the radar observation, 2) obtain the future positions of the clouds or moist air masses which have positioned at the storm groups by computing their trajectories at 500, 700, and 850-mb levels. 3) estimate the most probable weather from the configurations of trajected clouds and moist air at the three levels under the assumptions about the growth and dissipation of rain particle. The vertical component of the trajectory (distribution of Z-component of flow) and the influence of radiation (solar and nocturnal) to precipitation also be considered in this stage. The case study of this technic are made for six different storm cases, and obtained very satisfactory results except one case which showed big wind shear. These case study also showed good explanation about the phenomenon of bad weather persist in a cold air pool and of the rain systems near a hurricane. This technic will best suitable for the very short range weather forecasting from 3-hour and up to 15 or 18-hour ahead. Isentropic trajectories are also constructed and compared with constant pressure level trajectories.

[学科分类] 大气科学