In some regions of the Earth, the air has low movement due to weak pressure at times. Therefore, the air above these regions eventually carries certain characteristics of the temperature and humidity of that region.
For example, the air laying over the ocean has more moisture. While the air laying over the polar region is colder. So, the air mass is such a large body of air lying over a specific region.
What is an air mass?
An air mass is a large volume of air that having uniform temperature and humidity in a horizontal direction. The temperature and humidity of the air masses are similar to the underlying area.
The boundary between two air masses called a front. the area of the earth where air mass originates is called source region.
Types of air masses
Any air mass has two main characteristics temperature and moisture. Depending on these characteristics, there are five types of air masses.
The naming of air mass contains two letters. The first letter shows humidity and it is written in lowercase letters. The second letter indicates the temperature and it is written in capital letters.
Based on moisture content, air masses have two types: continental (c) and maritime (m). the continental air mass is dry or has low moisture. While the maritime air masses are moist.
Based on temperature content, air masses have three types: tropical (T), polar (P), and arctic (A). The tropical air masses are hot and polar air masses are cold. While Arctic air masses are extremely cold.
1. Continent arctic (cA)
Continent arctic air masses are very cold, very stable, and extremely dry. they usually form over the north pole regions.
2. Continent polar (cP)
These air masses are usually cold and dry. cP air masses originate over high latitude regions such as Siberia and northern Canada. These polar regions are generally found between 40 to 60 degrees.
3. Continental Tropical (cT)
These air masses originate in tropical regions, between 23 degrees N to 23 degrees S. In the tropical continent, most deserts are found such as the Arabian desert and the Sahara Desert. The air in the regions is usually hot and very dry.
4. Maritime polar (mP)
The sea of the polar regions usually sources region of the mP air masses. Her, air masses cold and contain moisture.
5. Maritime tropic (mT)
These air masses generally originate over the tropical oceans. These air masses contain a lot of moisture. they are warmer and unstable.