How to look at the sky at night?

How to look at the sky at night? In fact, the constellation position runs according to certain laws, which corresponds to the climate change on the earth. After long-term observation of astronomical phenomena, our ancestors found: "bucket handle refers to the east, the world is spring, bucket handle guides, the world is summer, bucket handle refers to the west, the next is autumn, bucket handle refers to the north, and the world is winter." This is to judge the season by observing the position of the Big Dipper at dusk. And this method of observing the regular changes of the sky to determine the four seasons is called "observation time", which was used by the ancients for a long time in the era without calendar.

Firstly, the characteristics of astronomical phenomena are introduced. Mountains and even hills are the influencers of weather.

Compared with other places on the earth, mountainous areas can produce greater changes in wind, temperature, precipitation and lightning, which often pose a threat to travelers in mountainous areas. Wind and mountain wind are also various, which can be divided into the following types: uphill wind, which is caused by the change of temperature difference in mountainous areas. Cold air goes down the mountain at night and warm air goes up the mountain during the day. Uphill wind usually occurs within 15-45 minutes after sunrise, and reaches the maximum wind speed at noon or when the ground solar energy is strongest. Generally speaking, the southern slope receives the most energy, so the uphill wind is the strongest. There is no headwind on the north slope. The wind going up the mountain usually goes straight into mountain streams and canyons. When there are clouds in the sky, intermittent sunshine can control the occurrence and stop of uphill wind in time like a "switch". Downhill winds are relatively mild and stable, mostly near the surface. After sunset 15-45 minutes, the wind began to blow from the top of the mountain to the bottom of the canyon until sunrise the next day. Sinking wind, that is, "glacier wind". It often appears on glaciers and is not affected by day and night changes. Because the surface temperature of the glacier is always lower than the temperature above it, it always blows down the slope. However, when the glacier extends to the end of the slope, there will also be uphill wind, and the intensity of this wind is often controlled by the size of the glacier. Canyon wind, controlled by topography, is also a mixed wind of uphill wind and downhill wind, which mainly appears near the semi-closed valley with cracks on the slope. It is also controlled by the sunshine temperature difference, that is, it is mostly the upper valley wind at noon and turns into the lower valley wind at night, and the mountain valley wind often has strong gusts. Whirlwind is also a common wind in mountainous areas. Whenever the ground changes obviously and the surrounding wind is strong, it will produce a whirlwind. In most cases, cyclones have instantaneous characteristics and are mostly formed on the north wind slope. Precipitation, there is a lot of updraft in mountainous areas, which makes the air cool continuously, so the precipitation usually increases with the increase of height. In humid tropical areas, the increase of precipitation in mountainous areas is particularly obvious. Flash floods caused by heavy rainfall are the biggest threat to mountain travelers. Fog is the most common in mountainous areas, but it is actually a cloud that touches the surface. Sometimes the valley may be foggy all day. Lightning, mountaineers, hikers and campers are particularly vulnerable to lightning strikes in mountainous areas. The rising wind generated by the rugged mountainous terrain makes the thunderstorms there more violent and frequent. Temperature, temperature is very important for mountain travelers. In mountainous areas, the temperature decreases with height, and it is about twice as high in summer as in winter. The relative humidity on the mountain peak is much higher than that in the valley. In this case, most clothes are bad insulators, so it is not easy to keep warm in winter and cool in summer. Generally speaking, the average temperature drops 1 for every 300m increase in height. 2 degrees, for mountain travelers' reference.

Second, the sky strategy Thunderstorms usually start with small cumulus clouds and then develop rapidly. After the development period of cumulonimbus, it enters the mature cumulonimbus stage, which is a severe, bad and rapidly changing weather.

Field activities personnel should pay attention to the following points:

1. Thunderstorms may occur when cumulonimbus clouds begin to accumulate and darken.

Thunderstorms usually last for a short time. Stay calm, don't be afraid, and stay where you can hide. The danger of lightning lies in penetrating objects and human bodies, causing fires, and the resulting thunder shatters people's eardrums.

So, you should remember:

1, cars are often excellent lightning protection facilities, you can hide in the car when lightning strikes.

2. The best place for protection is caves, ditches, canyons or open spaces under big trees.

3. If you are in the open air, you should squat twice as high as the isolated tree.

When you feel the charge, that is, when your hair stands on end or your skin vibrates, it is probably an electric shock. You should fall to the ground immediately to protect yourself.

If you avoid an isolated projection, the top of the projection should be at least15-20m higher than your head.

6. Stay away from vertical walls or cliffs, and avoid exposed peaks and ridges and flat and open terrain.

7. Avoid ground fissures, lichens and suspended rocks.

8. Never sit among scattered stones.

9. Tie yourself up with a rope in a dangerous place.

10. If you enter the cave for lightning protection, you should stay away from all vertical rock walls for 3 meters to avoid personal injury caused by electric conduction on the rock walls. When the mountain torrents are raining heavily, because the precipitation is very urgent, the surface has no time to absorb the rain, and it is difficult for earth and stone to stop the rain from leaking, which will aggravate the threat of mountain torrents. Therefore, when the thunderstorm activity intensifies, it is necessary to avoid the long ditch or the flat extension zone below the river bed that is most prone to water accumulation. Leave flood-prone areas, abandon equipment, and move to higher ground if necessary. Be careful not to try to wade knee-high streams on foot. Weather conditions will raise or lower body temperature and affect people's health. The three most influential weather factors are temperature, wind speed and relative humidity. In cold conditions, the influence of temperature and wind is inseparable, both of which often make people lose heat at the same time, and the insulation value of soaked clothes will drop by 90%. Therefore, in a cold environment, the simple and easy way to survive is to keep proper exercise and not sweat. In the hot and humid environment, people will have fatigue, headache, loss of appetite, insomnia, severe dehydration, general weakness, thermal convulsions and other phenomena, so we should pay attention to avoid outdoor activities in this climate.

Third, the general law of astronomical phenomena.

A. signs of better weather. During the day, the valley breeze usually blows from the bottom up, but at night it is just the opposite, usually blowing from the top of the mountain to the bottom of the valley.

2. During the day (especially in the morning), you can see that the clouds in the mountain pass gradually divide into fog and gradually dissipate.

At sunset in the evening, an orange or rose sunset (flaming clouds) appeared over the western valley.

There is fog at the foot of the mountain in the evening, and the weather is cold (cold at night), which indicates that the weather may be better the next day.

There is dew and frost on the grass in the morning.

6. The starlight is stable and rarely flashes.

Signs of bad weather

1. The valley breeze blows from the top of the mountain to the valley during the day and from the valley to the top of the mountain at night.

Silk clouds appeared in the morning, and then black clouds increased and slowly sank.

Clouds move rapidly and tend to increase, which may be a precursor to the storm.

The wind direction changes suddenly, becoming bigger and bigger, accompanied by dark clouds.

5. After dry heat or fog, the visibility suddenly increases.

6. Fog permeates the valley in the morning and will not dissipate at night.

7. There is a big halo around the sun during the day and a small halo around the moon at night, which is a sign of strong wind.

8. The stars twinkle before dawn.

9. The temperature rises in the evening and the night is warm and sultry.

10, the clouds rising in the half valley may be a sign of future storms.