Weather forecast of Longyou Xikou

The artificial precipitation enhancement operation in Hangzhou has a short-term effect on alleviating the high temperature weather in summer, but this precipitation enhancement operation has increased the rainfall in Hangzhou by less than 3 mm. After a short period of cooling, the surface temperature will return to the high temperature weather in summer. The only way to relieve summer heat is to avoid sun exposure, reduce outdoor activities and drink more water to reduce the rapid rise of body temperature.

The principle of artificial rainfall. The three elements of rainfall in nature include sufficient water vapor, rising and saturated airflow, and more condensation nuclei. Artificial rainfall is to use the different physical structures of the cloud to artificially sow related catalysts into the cloud to meet the three elements of rainfall. Common catalyst substances include silver iodide, dry ice or salt. When silver iodide is heated, it will form small particles in the air, which is the condensation nucleus. Condensed nuclei move with the airflow in the sky to form ice crystals. After reaching a certain weight, they fall to the ground under the action of gravity and melt in the process of falling, thus forming water droplets. The principle of dry ice and salt is the same. Artificial rainfall is the best scheme to alleviate drought and high temperature because of its low cost and high efficiency.

Benefits and hazards of artificial rainfall. The benefits of this artificial rainfall are quite obvious. Hangzhou also ushered in the first rain in the hot summer, alleviating the unbearable high temperature and water shortage of plants. However, it will get hotter after the rain in summer. When the water vapor in the sky enters the ground heated by solar radiation, it will vaporize quickly. Especially when there is little rainfall, the heat in the atmosphere will enter the air with water vapor, which will accelerate the heat transfer in the air. In addition, after the rain stops, the sun begins to shine again, and the water vapor will accelerate the temperature rise and the humidity in the air will increase. When the temperature is higher than the human body temperature, heatstroke will occur. At the same time, silver iodide used in artificial rainfall will pollute the environment and carbon dioxide will increase the greenhouse effect. Therefore, artificial rainfall can not effectively alleviate the high temperature.