165438+1October 12 in the morning, "lenticular clouds" appeared in the sky in Beijing. The meteorological department said it predicted that the weather would be better in the future. What is the reaso

165438+1October 12 in the morning, "lenticular clouds" appeared in the sky in Beijing. The meteorological department said it predicted that the weather would be better in the future. What is the reason? The formation of clouds is the magic of water vapor. There is a lot of water vapor in the atmosphere, 99.99% of which is concentrated in the troposphere which is the closest and most active to the surface. The decrease of ambient temperature or the upward movement of air make water vapor condense, and eventually form small water droplets or small ice crystals, which gather together in the sky, so clouds enter our field of vision.

When the wind, air pressure and temperature in the atmosphere change differently, the shape, size and height of the formed clouds are also different. Even due to the influence of mountains, lakes, valleys and other topography, the shape of clouds will be different.

Among the numerous clouds, lenticular clouds attract the public's attention with their peculiar shapes. Its name comes from Latin, which means "lentil", and it has a very unique convex lens shape, so some people call it UFO cloud. But in fact, lenticular clouds are normal clouds, which are common on ridges and mountains.

Lenticular clouds can be seen in low clouds, medium clouds and high clouds. Generally, the formation of lenticular clouds is mostly due to the influence of topography when airflow passes through hills, such as pod cumulus clouds in the middle cloud.

Lenticular clouds are usually formed by moist air flowing over ascending terrain (such as hills or peaks), regardless of altitude. When the atmosphere in this area is relatively stable, the air will fluctuate downward, rise invisibly and sink on the leeward side. If enough air climbs and is cooled, lenticular clouds will appear at the peak position.

Another reason for lenticular clouds is the convergence of local updraft and downdraft in the atmosphere. When the cloud formed by adiabatic cooling of updraft meets the obstruction of downdraft above, the cloud can't continue to spread upwards, and its edge will be evaporated and thinned due to the temperature increase of downdraft, so it is pod-shaped. Its cloud is thick in the middle, thin in the edge, clear in outline and white in color. On the same day, when the light shines on the clouds, there will be beautiful rainbow colors. Podlike cumulus clouds can also indicate the weather. When they appear in isolation without other cloud systems, most of them indicate sunny weather.