Whether the air pressure is low or high on a rainy day

It is low air pressure on rainy days.

Depression refers to the air pressure near the ground, which generally forms on land in summer. The well-known centers of low pressure are the Asian low pressure centers (Indian low pressure) and the Azores low pressure center. The airflow of the low pressure is upward.

And the higher the air flow, the lower the temperature, so the rain is formed. So the depression generally brings high winds and rain to the areas it passes through. It can alleviate the drought situation.

The weather controlled by the high-pressure system is sunny, because the high pressure near the ground means that in the vertical direction, the air is mainly moving vertically downward, and the closer to the ground, the higher the temperature, the more difficult it is for the water vapor in the air to cool and condense to form precipitation. So the weather was sunny. Like our usual autumn and autumn weather, the high weather is often generated by the control of the high pressure system.

It is low air pressure on rainy days.

Low air pressure is the air pressure near the ground, and the air flow of low air pressure rises upward, and the higher the air flow, the lower the temperature, so it is easy to form rainfall.

Low pressure, which generally brings high winds and rain to passing areas. Areas with high atmospheric pressure on the ground tend to be sunny, and areas with low atmospheric pressure on the ground tend to have cloudy and rainy days. Generally, high pressure and low pressure are relative and do not refer to the absolute value of atmospheric pressure.

Remember atmospheric pressure.

The size is related to the temperature, the higher the temperature, the greater the pressure, in fact, the factors that affect the density are not only the air temperature but also the content of different gases in the air. Water vapour.

The density is smaller than that of air, and the content of water vapor is high on rainy days, so the air pressure is low.

Low atmospheric weather.

Air pressure is closely related to the weather. Generally speaking, areas with high atmospheric pressure on the ground tend to be sunny, and areas with low atmospheric pressure above the ground tend to have cloudy and rainy days. The high pressure and low pressure mentioned here are relative and do not refer to the absolute value of the atmospheric pressure.

The air pressure in a certain area is higher than the air pressure in the surrounding area, which is called a high pressure area; The air pressure in a certain area is lower than the air pressure in the surrounding area, and it is called a low pressure area. At the same level, if the air pressure is not evenly distributed, the air will flow from the area of high pressure to the area of low pressure. As a result, when the air pressure in an area is high, the air in that area flows horizontally out of the surrounding area.

The above content reference: Encyclopedia - Low air pressure.

On a rainy day, the air pressure is low! Low air pressure refers to the air pressure near the ground, and the air flow of low air pressure is upward. The higher the airflow, the lower the temperature, so it is easy to form rainfall. Low pressure, which generally brings high winds and rain to passing areas.

Generally speaking, areas with high atmospheric pressure on the ground tend to be sunny, and areas with low atmospheric pressure on the ground tend to have cloudy and rainy days. Generally, high pressure and low pressure are relative and do not refer to the absolute value of atmospheric pressure.

Rain is low air pressure. The density of water vapor is smaller than that of air, when the air contains more water vapor, the air density will become smaller, and the air molecules with high pressure will be squeezed out by the water vapor and diffuse to the peripheral areas of the rainfall zone, the air pressure will decrease, and when the air pressure is low to a certain extent, the amount of water vapor will be enough to make it rain.

Barometric pressure is the abbreviation of atmospheric pressure, which refers to the atmospheric pressure acting on a unit area, and the international unit is Pascal, referred to as Pascal, and the symbol is Yinhong Pa.

In meteorology, people generally use kilopascal (kpa) or hectopa (hpa) as the unit of air pressure, and the air pressure decreases exponentially with the increase in altitude.

During the year, the air pressure in winter is higher than in summer, and in the atmosphere, the higher the temperature and the expansion of the gas, the less dense the gas will be, and the lower the air pressure.

Rainy days are usually low pressure grip on the base. The low air pressure is the air pressure near the ground in Hyokyung, and the air flow of the low pressure is upward. The higher the air current, the lower the temperature, so it is easy to form rainfall.

Hot air rises to get cooler.

High and low pressure readings are indicators of how much weight the atmosphere is pushing down towards a particular area. When the pressure is lower, the air can freely rise into the atmosphere, where it cools and condenses. This condensation can form clouds of water droplets and ice crystals. And finally, water vapor in the clouds.

It condenses with dust and other tiny particles and falls into rain. Without low pressure, most of the air and the water vapor in it cannot reach a high enough height of condensation to cause no rain. That's why when low pressure arrives, rain often follows.

Depression. Bring continuous rainfall.

The intensity of the rain varies, so continuous rain does not occur very often. When a long-term steady rainfall occurs, it is usually due to the position of the low pressure system relative to the warm front. Warm, moist air enters the area of low pressure and is pulled up on the cold air mass in front of the warm front.

This results in longer, longer-lasting rain and snow cycles.

Thunderstorms such as low pressure and high temperatures.

When low pressure is located in the cold front.

Straight ahead, warmer, unstable air ahead has the potential to become a thunderstorm in a counterclockwise rotating area of low pressure. This condition produces the most severe thunderstorms, with shorter, heavier rainstorms that often occur during the spring sail season and summer in many areas. The lower the air pressure, the more the air can rise to form storm clouds.

In general, the higher the cloud cover, the more likely a thunderstorm is.

Causes of the formation of low pressure.

The sun is the main cause of the differences in pressure around the world. Due to the rotation of the earth and the rise and setting of the sun, all parts of the world are subject to various temperatures at any given time. The temperature difference also affects the air pressure in the area.

The atmosphere is constantly adjusting to balance the pressures on Earth. Since the circulation of fluctuating pressure is driven by temperature changes, the high and low pressure areas will move in different places, which will lead to different weather conditions.

There is a relationship between air pressure and whether it rains, and if the air pressure is low, it is easy to rain, and if the autumn is high, it is not easy to rain.

Is there a relationship between air pressure and whether it rains? Yes, the lower the air pressure, the more likely it is to rain.

It is related to low pressure and easy to rain, and high pressure on sunny days.

The first factor that affects air pressure is temperature. "Winter is high and summer is low", I can understand the mountains. Because p= gh, the air density is high in winter because of the thermal expansion and cold contraction, so the pressure is strong.

The second factor that affects air pressure is humidity. I don't understand, why is it "sunny and rainy"? p=ρgh。

The density of water should be greater than that of air, right? Otherwise, the air should sink underwater, and the water should float on the air.

Low pressure near the ground, the air flow moves upward, and the air rises and cools to form precipitation.

Generally speaking, the atmospheric pressure is higher on a sunny day than on a cloudy day, and the atmospheric pressure in winter is higher than in summer. The magnitude of air pressure is related to altitude, atmospheric temperature, atmospheric density, etc., and generally decreases exponentially with the increase of altitude. There are diurnal and annual variations in air pressure.

During the year, the air pressure in winter is higher than in summer, and there is a maximum and a minimum value of air pressure during the day, which occurs at 9 10 o'clock and 15 16 o'clock, respectively, and a second highest and a second low value, which occurs at 21 22 o'clock and 3 4 o'clock, respectively.

The diurnal variation of air pressure is small, generally in kilopascals, and decreases with increasing latitude. The change of air pressure is closely related to the wind and the quality of the weather, so it is an important meteorological factor.

Measuring Tools:

There are two most common instruments for measuring air pressure: mercury barometer and empty box barometer.

Air has weight, air pressure refers to the force exerted by the atmosphere on the unit area, the so-called air pressure in a certain place, refers to the total weight of the air column that extends vertically up to the top of the atmosphere per unit area.

In meteorology, hexopascals are commonly used as a unit of measurement for barometric pressure, which is specified as follows: the barometric pressure at sea level with a temperature of 0 and latitude of 45 degrees as a standard condition is called 1 atmosphere, and its value is 760 mm of mercury column height, or equivalent to heclapascal.

Before rain, there is a high humidity in the air and a high level of water vapor. Lowers atmospheric pressure.

Junior high school physics tells us: "The change of atmospheric pressure is closely related to the weather Generally speaking, the atmospheric pressure is higher on sunny days than on cloudy days, and the atmospheric pressure in winter is higher than that in summer."

When we heat a closed container containing air, the pressure will of course increase The situation is different for the atmosphere When the atmospheric temperature in a certain area rises due to a certain factor, it will inevitably cause the expansion of the air volume, and the air molecules will inevitably spread to the surrounding area The temperature is high, and the gas molecules will certainly move faster, which will become a factor that promotes the increase of pressure, but on the other hand, as the temperature increases, the gas molecules will spread around, and the number of gas molecules in the area will decrease. As to which of these two factors plays a major role, let's take a look at the actual situation of the change of air pressure on the continents and oceans as a function of air temperature. We say that in summer the temperature on the continent is higher than that on the ocean, and the pressure on the continent is lower than that on the ocean because the air on the continent spreads to the ocean; In winter, the continental temperature is lower than that of the ocean, because the air over the ocean is to diffuse to the continent, and the pressure on the continent is higher than that on the ocean, and it can be seen that diffusion plays a major and decisive role in the two factors of temperature change and molecular diffusion It should be pointed out that the diffusion here refers to the lateral flow of air Because the vertical flow of air does not change the weight of the vertical column (some literature says that the change in air pressure due to temperature is the result of air sinking and floating, which is inappropriate). Therefore, the pressure of the atmosphere cannot be changed (the effect on the gravitational acceleration g due to the change in altitude is completely negligible).

The air pressure is high on a sunny day.

Changes in atmospheric pressure are related to the weather. The atmospheric pressure in the same place is not exactly the same at different times. We know that water vapor is less dense than air, and when there is more water vapor in the air, the air density becomes less and the atmospheric pressure decreases.

Generally speaking, the atmospheric pressure on a rainy day is smaller than that on a sunny day, and a sudden decrease in atmospheric pressure on a sunny day is a precursor to impending rain. It has been raining for several days and the atmospheric pressure has become stronger, so it is expected to clear soon. In addition, changes in atmospheric pressure are also related to temperature. Because the air density becomes less when the temperature rises, the atmospheric pressure is lower when the temperature is high than when the temperature is low.