Why is the denser the isobar, the stronger the wind? 10

If the isobars are denser, it means that the pressure gradient is greater and the wind is stronger; Conversely, if the isobar is sparser, the smaller the pressure gradient and the weaker the wind.

Atmospheric pressure. Air molecules have weight due to gravity, and the weight of the air on the surface of the earth, known as barometric pressure, is usually measured in hectopascals (HPA).

The air pressure decreases with altitude. As can be seen from Figure 2-5, the higher the terrain, the thinner and less dense the air, and the natural decrease in air pressure.

At the same altitude, the air pressure decreases as the air temperature increases. This is because when the air is heated, the volume expands, the density decreases, and the air pressure decreases. Conversely, if the air cools and contracts, the density increases and the air pressure increases.

Isobar. An isobar is a line connecting places with the same air pressure on a weather map. If the medium pressure line in the weather map is a closed curve, and its central pressure is higher than that of the surrounding area, it is called the high pressure center; Otherwise, it is called a low pressure center.

Wind is the horizontal flow of air, and the air flows from the high pressure area to the low pressure area, which produces the wind. If the isobars are denser, it means that the pressure gradient is greater and the wind is stronger; Conversely, if the isobar is sparser, the smaller the pressure gradient and the weaker the wind.

Cyclones, anticyclones.

The center of the depression is formed by the convergence of the air flow from the periphery to the center, forming a cyclone, and rotates counterclockwise in the Northern Hemisphere due to the influence of the Earth's rotation deflection force. In the Southern Hemisphere, it is clockwise. In the cyclone area, the airflow rises and it is easy for clouds to cause rain, so the weather is changeable.

The high pressure center is called an anticyclone because the air flow diverges from the center to the surrounding areas, and the air flow direction is opposite to the cyclone, which rotates clockwise in the northern hemisphere due to the influence of the earth's rotation deflection force. In the Southern Hemisphere, it is counterclockwise. Under the influence of an anticyclone, the air flow sinks and cannot rise to cause rain, so the weather is stable, sunny and dry.

.1.Hyperbarometric pressure is an area where the air pressure is higher than the surrounding environment, and there is also a center of high atmospheric pressure.

The air in the high pressure will flow to the nearby places with low air pressure, so the air above it will continue to flow in to replenish it, thus forming a downward airflow. As the air flows downward, the water vapor gradually dissipates and the temperature gradually rises, so it is usually sunny and good weather near the center of high pressure.

2.Low air pressure is "the rise of air from the ground to the heights".

Usually the air on the ground is relatively hot, and the water evaporation effect is large, so the humidity is high and the water vapor content is high

However, since the water saturation of hot air is greater than that of cold air, it is not necessarily saturated even if the water content of the ground is 100% when it rains The temperature of the air on the ground will decrease rapidly when it rises to high altitude, and the water saturation will decrease but the water content will remain unchanged, and when the water content exceeds saturation, the water vapor gaseous state will change back to water Liquid or ice crystals Solid state This is the cloud. And when the air supports the water less than the gravity of the water, the water will fall, and it will not evaporate before it falls to the ground, and it will become rain.

3.There is an atmosphere around the earth, and the atmosphere is attracted downward by gravity, and there is a force to press downward, just like a person has weight, and the atmosphere also has weight, and this weight is atmospheric pressure (referred to as air pressure).

Wind speed, pressure difference, distance difference.

On the same map, the denser the isobars, the greater the pressure gradient, and the greater the corresponding horizontal pressure gradient force, so the greater the wind. The pressure gradient refers to the difference in air pressure between unit distances, and its magnitude is equal to the purification rate of air pressure with distance. An isobaric line is a closed line formed by connecting places with equal air pressure in a certain period of time on a floor plan.

The isobars are dense and indicate the degree of difference in air pressure in the horizontal direction. On the same map, the denser the isobars, the greater the pressure gradient and the stronger the wind; Conversely, the sparser the line, the smaller the pressure gradient and the weaker the wind. Whereas, the barometric pressure gradient refers to the unit distance.

The difference in air pressure, the magnitude of which is equal to the rate of change of air pressure with distance. Isobaric line refers to a closed line formed by connecting places with equal air pressure in a certain period of time on a floor plan.

On the same isobar diagram, the air pressure difference between two adjacent isobars is equal. If the isobars are dense, it means that the greater the pressure difference within the horizontal unit distance, the greater the pressure gradient force and the greater the wind.

In this diagram, there are three isobars on the surface of about 1,000 kilometers at A, with a difference of 8 hPa, and at B, there are two isobars on the surface of about 1,000 km, with a difference of 4 hPa, and the wind at A is stronger than that at B.

On the same map, the denser the isobars, the greater the pressure gradient, and the greater the corresponding horizontal pressure gradient force, the greater the air flow (wind) velocity.

The density of the isobar reflects the magnitude of the horizontal pressure gradient force (the larger the spacing between the two isobars, the sparser the isobar, the smaller the horizontal pressure gradient force, and vice versa) to determine the magnitude of the wind force. Isobars are dense - horizontal pressure gradient force - wind force; Isobars are sparse - low horizontal pressure gradient force - small wind force.

When comparing the magnitude of wind power on different sheets, you should also pay attention to the similarities and differences between the barometric pressure values and the scale bar to prevent errors in judgment.

Why is it as follows:

The denser the isobaric pressure, the more significant the difference in the vertical linear pressure in the same climate field and the same pressure field, which in turn indicates that the airflow movement is strong and the horizontal pressure gradient force is large. The magnitude of the wind speed depends on the horizontal pressure gradient force, so it is said that "the wind force is stronger where the isobars are dense".

PS: Just remember this knowledge.

"is the stable wind direction" indicates that it is the final direction, reaching the state of force equilibrium (horizontal pressure gradient force, friction force, geostrophic deflection force);

Until then, the wind speed has been in an accelerating state (the resultant force of the frictional force and the geostrophic deflection force is less than the horizontal pressure gradient force), so the wind speed is 1<2<3<4.

The wind is unstable, the wind moves through the isobar in the order of , so the gas block will accelerate to the maximum velocity.

If the wind is parallel to the isobar, then the wind speed > is indeed a large pressure gradient, and the crossing of the isobar in the diagram makes the wind accelerate more.

The denser the isobar, the greater the pressure gradient force and the greater the wind force, which is suitable for comparing the wind magnitude after the wind has stabilized.

For before stabilization, the wind is getting stronger. In terms of 4, the wind is the highest and then decreases sequentially.

Hope it helps.