How's the weather?

[explanation] 1. Atmospheric conditions and phenomena, such as wind, lightning, thunder, frost and snow.

2. meteorology.

3. Scenes; Situation. Like a new atmosphere.

The general name of various physical phenomena and processes in the atmosphere, such as cold and hot, dry and wet, wind, clouds, rain, snow, frost, fog, lightning and so on.

Meteorological observation items include: temperature, humidity, ground temperature, wind direction and speed, precipitation, sunshine, air pressure and weather phenomena.

The objects of meteorological research are the laws of atmospheric motion in each layer of the atmosphere, the weather phenomena in the troposphere and the distribution of drought, flood and cold and warm on the ground. Such as clouds, fog, rain, snow, hail, lightning, typhoon, cold wave and so on. Are our common weather phenomena. Its research scope is the atmosphere on the earth's surface, which is about 3000 kilometers thick and can be divided into troposphere, stratosphere, mesosphere, natural layer and outer layer from bottom to top.

1. halo

There is a cloud in the sky. When sunlight or moonlight refracts and reflects through ice crystals in clouds, it will produce a colorful halo around the sun or moon. The order of halo colors is internal infrared purple. These seven color rings are called solar halo or lunar halo, which are collectively called solar halo. Among them, the halo with an angular radius of 22 degrees is the most common for observers, which is called 22-degree halo. Occasionally, you can see a halo with an angular radius of 46 degrees and other forms of halo-like light arcs. Halo occurs because of cirrostratus, and cirrostratus is often hundreds of kilometers away from the rain front area. With the advance of the front, the rain area may move in the near future, so halo often becomes a harbinger of rainy weather.

2. China

There is a transparent thin cloud in the sky, and the water droplets in the cloud are uniform in size. If the cloud is composed of ice crystals, the ice crystals should be uniform in size. Moonlight or sunlight is diffracted by uniform cloud droplets (water droplets or ice crystals) when passing through the clouds, resulting in an inner ultraviolet red ring around the moon or sun, which is called Hua. Because the sun is too bright, it is not easy for people to observe the sunrise, and moonlight is more common. The flowers near the moon disk are also called canopy. Usually the purple of the canopy is not obvious, so the inner ring is blue-green, the outer ring is mainly yellow, and the outer ring is red. Sometimes after a dark circle outside the crown, one or even several concentric rings with the same color order as the crown appear, but the brightness is much weaker, which is called Yahua.

3. Rainbow and neon

Sunlight, which contains seven colors of light, is water droplets (raindrops or fog droplets) injected into the atmosphere. Various colors of light can be refracted and reflected to form a colorful light arc ring on the rain curtain or fog curtain. When the angle radius of the light arc ring to the observer is about 42 degrees and the halo color sequence is internal ultraviolet red, it is called rainbow.

On the outside of the rainbow, sometimes a weak color halo appears, and the angular radius of the halo to the observer is about 52 degrees. The order of color rings is opposite to that of rainbow, that is, internal infrared purple, which is called neon or auxiliary rainbow.

Rainbow and neon can only be observed if they stand with their backs to the sun. In summer evening, when the sky in the west is sunny and the sky in the east is rainy, it is easiest to see rainbows and neon lights.

4. Dusk

Before sunrise, that is, before the sun is above the horizon, the sun shines into the upper atmosphere and is scattered by atmospheric molecules, resulting in a slightly brighter sky and a slightly brighter ground. The light from this moment until the sun comes out of the horizon is called dawn.

After sunset, that is, after the sun falls below the horizon, there is still a time when the sun can shine on the upper atmosphere, and the sky and the ground remain dark because of the scattering of air molecules. This light is called dusk.

The photosynthesis of dawn and dusk is called twilight. Dawn is called dawn, and dusk is called dusk. Due to the different standards for the beginning and end of dawn, it is usually divided into civil twilight, sea dawn and astronomical dawn. On sunny days, when the angle of the sun below the horizon is about 7 degrees, civil dawn begins and dusk ends; At about 12 degrees, the voyage begins at dawn and ends at dusk; At about 18 degrees, astronomical dawn begins and dusk ends. The duration of dusk is the shortest at the equator and increases with the increase of latitude.

Related words:

Meteorological Observatory: A scientific institution that observes, studies and forecasts the weather in the atmosphere. Smaller ones include weather stations and weather stations.

Colorful weather: describe all kinds of scenery and things, very spectacular.