What is the weather like?
Meteorology
[Explanation] 1. The state and phenomena of the atmosphere, such as wind, lightning, thunder, frost, snow, etc.
2. Meteorology.
3. Situation; situation. Such as a new atmosphere.
A general term for various physical phenomena and physical processes such as heat and cold, dryness and humidity, wind, clouds, rain, snow, frost, fog, thunder and lightning in the atmosphere.
Meteorological observation items include: temperature, humidity, ground temperature, wind direction and speed, precipitation, sunshine, air pressure, weather phenomena, etc.
The objects of meteorological research are the laws of atmospheric movement in each layer of the atmosphere, the weather phenomena occurring in the troposphere, and the distribution of drought, flood, and heat on the ground. Clouds, fog, rain, snow, hail, thunder and lightning, typhoons, cold waves, etc. are all our common weather phenomena. Its research scope is the atmosphere on the earth's surface, which is about 3,000 kilometers thick. From bottom to top, it can be divided into the troposphere, stratosphere, mesosphere, natural layer and outer layer.
1. Halo
There is a layer of high clouds in the sky. When sunlight or moonlight passes through the ice crystals in the clouds, it is refracted and reflected, resulting in a colorful halo around the sun or moon. The order of halo colors is inner infrared violet. These seven color rings are called the solar halo or the lunar halo, collectively called the halo. Among them, haloes with an angular radius of 22 degrees are the most common and are called 22-degree halos. Occasionally, haloes with an angular radius of 46 degrees and other forms of light arcs similar to halos can also be seen. Halos appear due to the presence of cirrostratus clouds, and cirrostratus clouds are often located hundreds of kilometers away from the frontal rain area. As the front advances, the rain area may move in soon, so halos often become a precursor to rainy weather.
2. Hua
There is a thin layer of light-transmitting clouds in the sky. The water droplets in the clouds are uniform in size. If the cloud is composed of ice crystals, the ice crystals must be uniform in size. When moonlight or sunlight transmits through clouds, it is diffracted by uniform cloud droplets (water droplets or ice crystals). As a result, an inner ultraviolet red colored ring is formed around the moon or sun close to the moon or sun disk, called a bloom. Because the sun is too bright, it is difficult for people to observe the sunrise, while the moonrise is more common. The flower that is close to the moon disk is also called the canopy. Usually the purple color of the canopy is not very obvious, so the inner ring is cyan blue, the outer ring is mainly yellow, and the outermost part is red. Sometimes, after a dark circle outside the canopy, there will appear one or even several concentric rings with the same color order as the canopy but with much weaker brightness, which are called secondary blooms.
3. Rainbow and neon
The sun's rays containing seven colors of light are ejected into the water droplets (raindrops or fog droplets) in the atmosphere. After the various colors of light undergo refraction and reflection, they can Creates a colorful light arc ring on a rain or fog screen. When the angular radius of the light arc ring to the observer is about 42 degrees and the color order of the light ring is inner ultraviolet red, it is called a rainbow.
Outside the rainbow, sometimes there is a colored halo that is weaker than the rainbow. The angular radius of the halo to the observer is about 52 degrees. The order of the color rings is opposite to that of the rainbow, that is, inner infrared and purple, which is called inner infrared and purple. Neon or secondary rainbow.
Hongs and neons can only be observed by standing with your back to the sun. In the evening of summer, when the sky is clear in the west and there are clouds and rain in the east, it is easiest to see rainbows and neon lights.
4. Twilight
Before sunrise, that is, before the sun appears above the horizon, sunlight shines into the upper atmosphere. The sunlight is scattered by atmospheric molecules, causing the sky to be slightly bright and the ground to be slightly bright. , the light from this moment until the sun appears above the horizon is called dawn.
After sunset, that is, after the sun sinks below the horizon, there is still a period of time when sunlight can reach the upper atmosphere. Due to the scattering of air molecules, the sky and the ground remain twilight. The light during this period is called twilight. .
Dawn and twilight are collectively called twilight. The twilight period is called dawn, and the twilight period is called dusk. Because the standards for the beginning and end of twilight are different, they are usually divided into civil twilight, nautical twilight and astronomical twilight. On a clear day, civil twilight begins and ends when the sun is approximately 7 degrees below the horizon; nautical twilight begins and ends when approximately 12 degrees; and astronomical twilight begins and ends when approximately 18 degrees. The duration of twilight is shortest at the equator and increases with latitude.
Related words:
Meteorological observatory: a scientific institution that observes, studies and forecasts the atmosphere. Smaller ones include weather stations, weather posts, etc.
Thousands of things: describing scenery and things that are diverse and very spectacular.