Why does it sometimes thunder on sunny days?

Lightning is only a discharge phenomenon of strong electric field between different parts of thunderstorm clouds or between clouds and the ground due to different charging properties. Because the lightning passage is narrow and the current passes too much, the air column in the lightning passage will burn white and glow, and the surrounding air will suddenly expand when heated, and the cloud droplets will suddenly vaporize and expand due to high heat, thus making a huge sound-thunder. Lightning generated in and between clouds is high-altitude lightning; The lightning generated in cloud lightning is "floor lightning".

The huge current, blazing high temperature, electromagnetic radiation and accompanying shock wave caused by lightning landing are so destructive that they can cause casualties and damage to buildings. For example,1At 7: 20 on April 25th, 1986, the Guanyin Pavilion in Shuangjing, Xiaozhuang Township in Xupu County, Hunan Province and other places were covered with dark clouds, mixed with wind and rain, and lightning and thunder ... With a strong flash, a deafening thunder thundered to three townships and six villages, and suddenly there was chaos, lightning and thunder. According to the investigation of the county joint investigation team, 7 people were killed and injured by lightning on the spot 10, of which 3 were seriously injured. One of the deceased's hair and clothes were all burnt, and his body was burnt and deformed, which was terrible.

After the lightning accident, it was found that the installation of wires in the homes of residents in this area was chaotic and the wiring position was very low. Five of the seven people who died were struck by lightning under the lights and switches. Before lightning strike, the room was quite humid, which created conditions for the formation of lightning strike accidents. Therefore, the installation of wires must meet the requirements. When lightning strikes, it is one of the important measures to stay away from conductive metal objects and keep indoors dry.

The harm of lightning to human body includes the direct action of current, overpressure or electric power and high temperature. When a person is struck by lightning, the current will pass through the human body quickly. In severe cases, it will lead to heartbeat, respiratory arrest and brain tissue hypoxia and death. In addition, when lightning strikes, sparks will be generated, which will also cause different degrees of skin burns. Lightning injury can also cause dendritic lightning stripes, epidermal peeling, intradermal bleeding, eardrum or visceral rupture.