Why is it raining?

Rain is water drops falling from the clouds. Water on land and sea surface evaporates into water vapor. The picture of rain on water vapor (19) rises to a certain height and turns into small water drops when it is cold. The photo of the rain collected some small water droplets and formed a cloud. They collide with each other in the cloud and merge into large water droplets. When it is too big for the air, it will fall from the clouds and form rain. There are many reasons for the rain, and the manifestations are unique, including Mao Mao rain, continuous rain and pouring rain. Rain is the most important fresh water resource in human life, and plants thrive on the moisture of rain and dew. But the flood caused by rainstorm will also bring great disaster to mankind. After the water on the earth is irradiated by sunlight, it becomes steam and is evaporated into the air. Water vapor condenses into small water droplets when it meets cold air at high altitude. These water droplets are very small, with a diameter of only 0.000 1 ~ 0.0002 mm, and the largest is only 0.002 mm. They are small and light, and are held up in the air by the updraft in the air. It is these small water droplets that gather in the air to form clouds. These small water droplets will become raindrops and fall to the ground, and the volume will increase by about 1 10,000 times. How did these small water droplets increase their volume to more than 654.38+00,000 times? It mainly relies on two means, one is condensation and sublimation. The second is to rely on the collision and increase of cloud droplets. In the initial stage of raindrop formation, cloud droplets mainly condense and condense themselves by constantly absorbing water vapor around the cloud. If the water vapor in the cloud can be constantly replenished and replenished, so that the surface of the cloud droplets is often in a state of supersaturation, then this condensation process will continue, making the cloud droplets grow and become raindrops. However, sometimes the water vapor content in the cloud is limited, and in the same cloud, the water vapor is often in short supply, so it is impossible to make every cloud droplet grow into a larger raindrop, and some smaller cloud droplets have to be merged into a larger cloud droplet. If there are water droplets and ice crystals in the cloud, the process of condensation and sublimation will be greatly accelerated. When the cloud drops increase to a certain extent, due to the increasing volume and weight of large cloud drops, they can not only catch up with the slower small cloud drops, but also "swallow" more small cloud drops, making themselves stronger. When the big cloud drops get bigger and bigger until the air can no longer hold them, they fall straight from the clouds to the ground and become our common rain. Scenery of rain (20 photos) There are many kinds of rain. Besides acid rain and colorful rain, there are many interesting rains, such as frog rain, iron rain, golden rain and even modesty. Are all masterpieces of tornadoes.

classify

1. According to the causes of precipitation, it can be divided into convective rain, frontal rain, topographic precipitation and typhoon rain (cyclone rain). 2. According to the amount of precipitation, it is divided into six grades: light rain, moderate rain, heavy rain, heavy rain, heavy rain and heavy rain. Light rain: 0. 1 ~ 9.9mm/ day; Moderate rain: 10 ~ 24.9 mm/day; Heavy rain: 25 ~ 49.9 mm/day; Heavy rain: 50 ~ 99.9 mm/day;