When we look up at the sky, we might see sunshine or clouds, or we may see rain or stars at night. But the planet is a complex system of different parts and, of course, weather is no exception. There are a handful of different air masses around the planet, which provide temperatures and moisture (or lack of) in different regions and environments.
To start, there are two kinds of air masses, maritime and continental. The difference between the two can vary a lot, but the main difference is simple. Maritime air masses are over the larger bodies of water around the globe. Continental air masses are mainly over land. To distinguish the differences of air masses, a code system is used (like all other weather components). But this system is easy to understand, using two or three letters to show what mass is which.
Polar maritime (mP) is cold air mass over a body of water. Typically this cool and damp air starts off on the colder side, but once it moves over the ocean, it heats up and provides moisture for plants to grow.
Polar continental (mC) are typically sitting over Siberia and Canada. Because these masses of cold air can stretch for thousands of miles, the opportunity for warmth doesn’t happen as often, and leaves winters a bit more harsh. When crossing water areas, the air mass can accumulate moisture, and we can get snow from this system.
Antarctic continental (cAA) sits in Antarctica. This air is very cold and extremely dry (think desert dry). Once it hits the ocean area surrounding the continent, it becomes warmer and collects moisture, making it more of a polar maritime (mP) air mass.
Equatorial maritime (mE) is quite the opposite of cAA air. This air is quite warm, and holds a lot more moisture. It provides tropical rains to the areas of land located near the equator. The temperatures do change in this air, but the range of temperatures doesn’t vary as much as others.
Tropical continental (cT) is also located in warmer climates, but the lack of moisture plays a major factor. Hot temperatures and dry air are two critical pieces for deserts, and this is exactly what cT is. This air mass moves around desert-like conditions, drying out the air and heating it up as well.
Tropical maritime (mT) is cooler in temperatures with plenty of moisture. They develop over tropical areas of the ocean, and when moving over land masses, can create either light drizzle or even fog.