Why does hot air go up and cold air goes down

The hot air temperature is high, the air volume expands when heated, the air density is small, and the weight is light, so the hot air rises. The temperature of the cold air is low, the volume of the air is heated, the air is dense and heavy, so the cold air goes down.

The rise of warm air and the fall of cold air is the simplest form of atmospheric movement, and the air circulation formed by the uneven heat and cold of the ground. The formation process is as follows: the atmosphere in the heated area expands and rises, a depression is formed near the ground, and a high pressure is formed at high altitude. The cold area is reversed, thus forming a pressure difference in the horizontal plane near the ground and at high altitude, which promotes the horizontal movement of the atmosphere and forms a thermal circulation at high and low altitudes.

After the loss of airflow in the hot place, the whole air column is reduced, and the ground forms low pressure, and the cold place forms high pressure, and the cold place forms a hot and cold airflow near the ground. Together with the rising and downdraft, the thermodynamic circulation is formed.

Due to thermal expansion and contraction, the heated gas expands and the density decreases.

So the hot air rises and the cold air falls.

Atmospheric convection The vertical upward motion of a mass of air in the atmosphere under the action of heat or power. Atmospheric convection can generate the exchange of heat, momentum and water vapor between the lower and upper layers of the atmosphere on the one hand, and the condensation of water vapor caused by convection on the other hand may produce precipitation. Atmospheric convection under thermal action mainly refers to the upward movement formed under the action of net Archimedes buoyancy in an atmosphere where the density of a mass of air is less than that of the ambient air, so that its buoyancy is greater than that of gravity.

Small, short-term, sudden, and cumulonimbus precipitation that is often seen in summer is often caused by atmospheric convection under the action of heat. Atmospheric convection under dynamic action mainly refers to the upward movement formed under the condition of horizontal convergence of airflow or the presence of topography. Precipitation over a wide area in the atmosphere is often caused by the convergence and uplift of fronts and associated airflows, while precipitation in fixed areas near mountain ranges is often caused by topographic forced uplift.

Some special topography (e.g., flare-shaped topography) creates atmospheric convection that has both the effect of topographic uplift and the effect of terrain in making the airflow converge horizontally.

On the one hand, the thermal and dynamic effects can form atmospheric convection, and on the other hand, atmospheric convection can affect the thermal and dynamic structure of the atmosphere, which is the feedback effect of atmospheric convection. This feedback is particularly important in tropical regions where the atmosphere is located, and the condensation heating of water vapor formed by atmospheric convection is often an important energy source for large-scale atmospheric movement in this region.

Because of the thermal expansion and contraction, the hot air because the volume has increased, and the total mass has not changed, so the density is small, put him in the normal air is like wood in the water, go up, cold air is the opposite, you compare him to the iron in the water!

Hot air molecules move fast so they go up.

Cold air moves slowly between molecules so it goes down relative to hot air.

Because hot air has a large internal energy and moves violently, cold air is the opposite.

The hot air has a high temperature, the molecules move fast, the volume increases, the density decreases, and it is thin.

Teach cold air to be relatively light, so the upward trend. On the contrary, cold air, which has a low temperature and is a compressed version of hot air, naturally sinks.

Due to the uneven cold and heat of the ground and the formation of air circulation, the ground is heated evenly, the air does not rise and fall, and when heated, the air near the ground will expand and rise, and gather in the air, so that the air density above increases, forming high pressure, on the contrary, forming low pressure, so that when the temperature is high, the air pressure will diffuse from the high place to the low air pressure.

The density of hot air is high and light, and the density of cold air is heavier, with the light one on the top and the heavy one on the bottom.

When the air is heated, the expansion density decreases and rises, and the cold air density is greater than the buoyancy received, so the cold air falls.

Hot air is warm and light, i.e., rising, and cold air is cold and heavy, i.e., descending.

It is atmospheric circulation: the hot air pressure is low, the cold air pressure is high, and the atmospheric thermodynamic circulation moves from low pressure to high pressure.

When the temperature of hot air is high, the volume expands, and the density decreases, and the opposite is true for cold air. The denser cold air sinks, and the less dense hot air rises.

The density changes when the air is heated.

The role of atmospheric pressure.

Heat rises and shrinks.

Hot air rises and cold air falls, which is why the higher the sky, the colder it is because the air is thinner.

1.Most people know that for every 1,000 meters of altitude gain, the corresponding temperature drops by 6 degrees Celsius.

The sun radiates a lot of sunlight, and it carries a lot of energy. But the atmosphere.

Transparent to most sunlight, especially visible light.

and some infrared light.

This light passes through the air and is not absorbed, so it is difficult for both high and low air to be heated by the sun. Unlike air, the earth's surface easily absorbs sunlight. The land and water absorb sunlight and heat it, and transfer the heat to the air that touches the ground.

2.There are many reasons why air masses rise. It may float upwards after heating up on the Earth's surface because the warm air is relatively buoyant. This is because the atmosphere is also affected by the Earth's gravity. As gravity decreases away from the Earth, the air above you densities.

will gradually decrease. Warm air rising is absolutely correct. As long as the air temperature is higher than the air temperature around the air mass, the air mass will keep rising.

This is because warm air is less dense and hence more buoyant. We have already explained that any rising air cools naturally, which is caused by cold air pressure and expansion.

3.The temperature change we feel is not directly from the heat of the sun, but from the air above the Earth. The Earth absorbs the sun's heat and distributes it into the surrounding air. As a result, the air gradually warms from bottom to top. Hence the Yamagoe.

high, the less heat in the atmosphere, the lower the natural temperature; In addition, the higher the mountain, the thinner the air, and the less heat is returned to the preservation stool. Therefore, when we climb Mount Zhaoyu, which is close to the sun, we feel not too hot, but too cold.

4.Troposphere.

Located at the bottom of the atmosphere, the higher the temperature trend is colder. For every 100 meters above sea level, the temperature drops by about degrees Celsius. Because its heat source mainly comes from the surface, and the heat conduction and long-wave radiation on the surface will heat the air at the bottom, the overall temperature change of the troposphere is hot at the bottom and cold at the top.

Because the air pressure is very low in the higher the weather, the insulation effect is poor, so a large part of the heat is lost.

This is because the higher the sky, the slower the cold air falls, and the slower the air rises, and the content of the hot air that rises is much less than that of the cold air.

This is because the colder the air and airflow will be. And it can also be affected by cold waves. So it can reach about minus 10 degrees.

It may be because some of the temperature differences in the sky are relatively large, and the higher the altitude, the thinner the air, and the faster the heat will dissipate, so the higher the sky, the faster the cold air will fall.

This may be due to the weather, which is why this happens, or it may be influenced by the atmosphere. That's why it's colder. Because the insulation effect is particularly poor, it will lead to some heat loss. That's why the higher it is, the colder it is.

Because the higher the altitude, the lower the air pressure, the poorer the heat preservation of the atmosphere, and the greater the amount of heat, the colder it gets.

One is that the energy of the air to absorb heat directly from the sunlight is weak, but it will be more effective in heating the air through the scattering and reflection of the ground.

Second, the density of air at different elevations is different, the mass of matter that absorbs sunlight and heats up is different, and the total amount of heat absorbed is also different.

Third, the state of the surface layer of the ground determines the ability to reflect and scatter sunlight differently.

This is because the air pressure is relatively low, and the air is relatively thin at this time, so the heat preservation effect of the atmosphere is also relatively poor, and in this case, the heat dissipates faster.

Hot air rises and cold air falls, so why is the sky getting colder and colder? Most people know that for every 1,000 meters of altitude gain, the corresponding temperature decreases6. Solar radiation produces a lot of sunlight, and it carries a lot of energy.

But the atmosphere is completely transparent to most of the Sun, especially visible light and some infrared. This light is slow to be digested and absorbed by the gas, so the air flying at high altitudes and at low altitudes cannot be warmed by sunlight. Unlike air, the surface of the earth is very easy to digest and absorb the sun.

The land and water digest and absorb the sun, heat it, and transfer the heat to the air that touches the ground.

There are many reasons for increased airflow. It is possible to heat up and float on the surface of the earth, as the warmest gases have the buoyancy of water compared to them. Mainly because the air is also affected by the Earth's gravity.

As the gravity of the Earth decreases, the density of the air above you will slowly decrease. The elevation of the warmest gases is absolutely correct. As long as the air temperature is higher than the air temperature around the mold, the air flow will continue to rise.

This is mainly because the density of the warmest air is lower, so the buoyancy of the water is higher. It has been explained that all elevated air cools because of the strong cold air and pressure surges.

The change in temperature that everyone feels is not immediately due to the heat of the sun, but from the air in the air of the earth. The Earth digests and absorbs the sun's heat and spreads it into the surrounding air. As a result, the gas slowly warms up from the bottom up.

Therefore, the higher the mountain, the lower the heat in the air, and of course the lower the ambient temperature; In addition to this, the higher the mountain, the thinner the gas and the less heat it stores. Therefore, when we climbed the mountain close to the sun, everyone felt that it was not too hot, but too cold.

The troposphere is located at the bottom of the atmosphere, where the higher the temperature trend analysis, the colder it gets. For every 100 meters above sea level, the temperature drops about. Because its pyrogen is mainly in the surface layer, the thermal conductivity and long-wave radiation of the surface layer will heat the air at the bottom end, so the overall ambient temperature change trend of the troposphere is hot at the bottom and cold at the top.

Because the higher the sky, the more severe the air in the troposphere, the worse the air conducts heat, and the ground receives heat more slowly, so the higher the sky, the colder it gets.

Because the air above is thinner, it will feel colder and colder. This is a very normal physical phenomenon.

I think it's because of the high altitude and thin air, so the heat radiation capacity of the ground is very poor, and it will be very cold.