Hangzhou implemented artificial precipitation enhancement, and eight rain bombs were successfully launched. Can it alleviate the hot summer weather?
The artificial precipitation enhancement operation in Hangzhou has a short-term effect on relieving the hot summer weather, but this precipitation enhancement operation has increased the rainfall in Hangzhou by less than 3mm. After a short period of cooling, the surface temperature will return to the hot summer weather. The only way to relieve the heat in summer is to avoid the sun exposure, reduce outdoor activity time 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, airflow rising and reaching saturation state, and more condensation nuclei. Artificial rainfall is to make use of the different physical structures of clouds and spread related catalysts to the clouds artificially, so as to meet the three elements of rainfall. Common catalyst substances include silver iodide, dry ice or salt. After being heated, silver iodide will form small particles in the sky, which are the condensation nuclei. The condensation 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 during the landing, thus forming water droplets. The principle of dry ice and salt is the same. Artificial rainfall has low cost and high efficiency, and is the best scheme to alleviate drought and high temperature.
the benefits and hazards of artificial rainfall. The benefits brought by this artificial rainfall are quite obvious. Hangzhou also ushered in the first rain in the hot summer, which eased the unbearable heat of the citizens and the water shortage of plants. However, the weather will get hotter after the rain in summer. When the water vapor in the sky enters the ground heated by solar radiation, it will be vaporized quickly. Especially when there is little rainfall, the heat in the atmosphere will enter the air with the water vapor, which will speed up the heat transfer in the air. In addition, after the rain stops, the sun will start to re-irradiate, and the water vapor will accelerate the temperature rise and the humidity in the air will increase. When the air 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 heat.