What is thunder and lightning?

Thunder and lightning is a magnificent and somewhat daunting discharge phenomenon accompanied by lightning and thunder.

Lightning usually occurs in cumulonimbus clouds with vigorous convection development, so it is often accompanied by strong gusts and rainstorms, sometimes accompanied by hail and tornadoes. The top of the cumulonimbus cloud is generally high, up to 20 kilometers, and there are often ice crystals in the upper part of the cloud. The glaze attachment of ice crystals, the breaking of water droplets and air convection make the clouds generate electric charges.

The distribution of charge in the cloud is complex, but in general, the upper part of the cloud is mainly positive charge, and the lower part is mainly negative charge. Therefore, there is a potential difference between the upper and lower parts of the cloud. When the potential difference reaches a certain degree, discharge will occur, which is our common lightning phenomenon. The average current of lightning is 30000 amperes, and the maximum current can reach 300000 amperes. The voltage of lightning is very high, about 100 million to 1 billion volts. The power of a moderate thunderstorm can reach 10 million watts, equivalent to the output power of a small nuclear power plant. In the discharge process, due to the sudden increase of temperature in the flash channel, the air volume expands rapidly, resulting in shock waves and strong thunder. When charged thunderclouds are close to the protrusions on the ground, intense discharges occur between them. Strong flash and explosion roar will appear at the lightning discharge site. This is the lightning and thunder that people see and hear.