The Nature of Winter Clouds and Precipitation in the HaiTuo Mountains and Their Modification By Artificial Seeding

The nature of winter clouds and precipitation in the HaiTuo mountains and their modification by artificial seeding

Xincheng Ma  Kai Bi  Xingcan Jia   JiuJiang Sheng  Yang Gao  Wei Zhou

Fei Wang  Jianli Ma

Beijing Weather Modification Office

This is the first papers describing field investigations, carried out from 2015-2016, of winter clouds and precipitation in the HaiTuo mountains of Beijing, and physical evaluations of their modification by artificial seeding.

It has been observed that (1) The effects of topography on cloud structure which produced maximum liquid water contents in the mountain front;(2) The winter precipitation formation mechanism is mainly the sublimation and aggregation, riming process is weak, The aggregation process mainly occurs between dendritic crystals;(3)From about 1.6km to surface the airflow over the Haituo mountains is generally east or southeast and the air is very dry, but above 1.6km the main airflow is southwest and the air is near water saturation between 1.5-3.5km.

  Airborne, ground and radar techniques used for evaluating the effects of artificial seeding on winter clouds and precipitation over the HaiTuo mountains are described. The clouds were seeded for half of hour with silver iodide. The amounts of silver in the snowfall increased during the predicted period-of-effect.