There is a snowball fight in Xinjiang in August. Why does it snow in August?

Subconsciously, everyone will think that it will snow only in winter. In fact, there is a difference between north and south. I put on my winter clothes when it snows in the north, and the islands in the south are still wearing short clothes and short sleeves.

Why is this? Chanel decrypts for you: Why does it snow in August?

snow

Snow is precipitation composed of a large number of white opaque ice crystals (snow crystals) and their polymers (snow masses).

Formation conditions of snow

Water vapor saturation

The maximum amount of water vapor that air can hold at a certain temperature is called saturated water vapor. The temperature at which air reaches saturation is called dew point. When saturated air is cooled to a temperature below the dew point, the excess water vapor in the air becomes water droplets or ice crystals. Because the saturated water vapor content of ice surface is lower than that of water surface, the water vapor saturation required for the growth of ice crystals is lower than that of water droplets. That is to say, water droplets can grow only when the relative humidity (relative humidity refers to the ratio of the actual vapor pressure in air to the saturated vapor pressure of air at the same temperature) is not less than 100%; As for ice crystals, they tend to grow when the relative humidity is less than 100%. For example, when the temperature is -20℃ and the relative humidity is only 80%, ice crystals can grow. The lower the temperature, the less humidity is needed for the growth of ice crystals. Therefore, in the high-altitude and low-temperature environment, ice crystals are more likely to be produced than water droplets.

There are condensation nuclei in the air.

Some people have done experiments, if there is no condensation nucleus, the water vapor in the air will only condense into water droplets if it is supersaturated to a relative humidity of more than 500%. But such a large supersaturation phenomenon will not exist in the natural atmosphere. So without condensation nuclei, it is difficult for us to see rain and snow on the earth. Condensation nuclei are tiny solid particles suspended in the air. The ideal condensation nuclei are those particles that absorb the most water. Such as sea salt, sulfuric acid, nitrogen and other chemicals. So we sometimes see clouds in the sky, but there is no snow. In this case, people often use artificial snowfall.

Is it true that it snows in August?

There are pictures to prove it, indeed. As can be seen from the pictures provided by netizen Weibo, the man taking pictures on the left in the above picture is wearing short sleeves, and the man wearing a shirt in the upper right corner of the picture is also wearing short sleeves. Because of the large temperature difference between morning and evening in Xinjiang, others wear coats, which is more in line with the climate characteristics of Xinjiang in August.

Why does it snow in August?

Reasons for sea area allocation

It is easier to snow at high altitude. Generally speaking, the higher the altitude, the lower the temperature. Because the main direct heat source of troposphere atmosphere is the ground, the farther away from the ground, the less ground radiation and the lower the temperature. Every altitude 100 meters, the temperature drops by 0.6 degrees Celsius (vertical temperature drop rate).

Although the temperature in August is the highest in the whole year, it will be lower at high altitude.

According to the characteristics that the temperature drops by 0.6 degrees Celsius every time the altitude rises 100 meters, we draw the following conclusions.

Altitude 1000m, the temperature drops by 6 degrees Celsius.

At an altitude of 2000 meters, the temperature dropped by 12 degrees Celsius.

At an altitude of 3000 meters, the temperature dropped 18 degrees Celsius.

At an altitude of 4000 meters, the temperature dropped by 24 degrees Celsius.

At an altitude of 5000 meters, the temperature dropped by 30 degrees Celsius.

At an altitude of 6000 meters, the temperature dropped by 36 degrees Celsius.

At an altitude of 7000 meters, the temperature dropped by 42 degrees Celsius.

At an altitude of 8000 meters, the temperature dropped by 48 degrees Celsius.

The snowy place is located in Duku Highway Tunnel. The winding and spectacular Duku Highway runs through Tielimaitidaban at an altitude of 3,700 meters in Tianshan Mountain. The Gendaban Tunnel in Harkjerr is 3390 meters above sea level, which is the highest tunnel in China. There is also a 100-meter snow corridor on expressway, which can make avalanches on cliffs fall into the deep ditch next to expressway.

Cold air and humidity

This can be said to have a great relationship with latitude. In low latitudes, the influence of cold air is less, while in high latitudes, the influence of cold air on temperature is greater.

According to the information provided by the forecaster of Dalian Meteorological Observatory, the local temperature has generally dropped due to a strong cold air. There is a large range of rainfall and short-term convective air in the surrounding area.

?

So as long as it meets the conditions of snow, it has nothing to do with the month. When it is summer in the northern hemisphere, it is already winter in the southern hemisphere. When the plain is hot in summer, Mount Everest is still covered with snow.