Being one of the most important elements of our environment, air plays a significant role in formation of weather patterns in a particular area. Although the words ‘air pressure’ and ‘weather’ sound like some scientific and technical terms, in reality they are very easy to understand.
Just bear with me few more minutes; I’ll show you how easy these two terms are to understand. Let me first tell you why it is easy. We all are habituated with the basic characteristics of air. And these basic characteristics are the reasons why weather is affected by air.
Still confused? Don’t worry. I’m not going to give up on you just yet! The atmosphere surrounding the Earth is made up of air and different other gaseous substances. You can compare the atmosphere to a vast ocean of air and the Earth is in the middle of that ocean.
Besides, air is an element that has mass and weight. That means this vast ocean of air inserts tremendous amount of pressure. So, isn’t it natural that the air will affect the Earth’s weather as weather occurs in that atmosphere?
In general, the force inserted by the air above the Earth is termed as air pressure. However, the air doesn’t exert equal amount of pressure on every parts of the Earth’s surface.
Scientists have discovered that the whole Earth’s surface is covered with areas of high air pressure and low air pressure. This phenomenon generally depends on two factors – altitude and temperature.
You probably can easily understand why altitude has an impact on air pressure. The area that is low-lying, pressure should be higher there simply because of greater amount of air compared to higher areas. So, air pressure at the sea level is the highest and it decreases gradually with altitude.
On the other hand, temperature also affects the air pressure to a great amount. We all have learned from our primary level science books that hot air is lighter than cold air. So, the air pressure must be lower in a hot area than a comparatively colder area.
As I’ve told you earlier, these areas of high pressure and low pressure cover the whole world. So, it is needless to say that air pressure plays a great role in the evolution of weather.
Before I jump into how does air pressure affect the weather, I want to take few more moments to clarify high and low pressure a little more. It’ll help you to understand the process very clearly and easily.
Basically, high pressure systems occurs in an area if the atmosphere over that particular area becomes heavier. As a result, the heavy air above will come down to the Earth’s surface. And the air present in that area will move away to create space for the heavy air.
Commonly, the warmer months experience high pressure. You’re more likely to enjoy a comparatively dry and stable weather pattern in those months. Besides, you’ll find the skies in high pressure areas very clear. You’ll also feel a gentle breeze there that will cool down the surrounding areas.
On the other hand, the air above a low pressure systems area is comparatively much lighter than the air below. As the heavy air on the Earth’s surface cannot go further below, it pushes away the lighter air above. As a result, a vacuum is created on the surface level and the air in the surrounding areas rushes towards it to fill up the void space.
Meanwhile, the rising air starts to cool down and form clouds in the sky. These clouds then come down to the Earth in the form of rain. Sometimes, snow is also formed depending on the temperature of the surrounding areas.
In general, colder months of the year experiences more low pressure situations. By now, you probably can guess why. The cold air on the surface level is heavier than the air above. And these low pressure areas are the reasons behind unstable weather conditions like snow, ice, rain, storm, etc.
Here’s a piece of visual on how atmospheric pressure affects the weather:
At a Glance: Influence of Air Pressure on Weather
We’ve understood from the discussion above that it is natural for air to drift from high pressure zones to low pressure zones. So, different air pressure zones in an area create a stream of wind. Although it is not visible, air pressure affects the weather pattern to a great extent.
- Rising air creates low pressure while sinking air creates high pressure.
- With high pressure, sinking air suppresses weather development.
- High air pressure produces clear sky, dry and stable weather.
- In a low pressure zone, wind is circulated inwards and upwards rapidly. As a result, air rises and cools; clouds and precipitate are formed.
- Low air pressure produces unstable weather conditions like rain or storms.
- Storms are the deep center areas of low pressure zones. It brings strong wind and rain.
As weather can change within a very short notice, the knowledge and understanding of weather conditions and their relation with air pressure will come in easy reach if you’re planning for an adventurous tour like trekking, hiking, etc. Just make sure your tour timing doesn’t coincide with a low pressure.
In my opinion, these are some of the basic ideas about air pressure and how they affect the weather. So, by now I’m sure you’ve a better understanding of how weather conditions are affected by air pressure.