Winds are all the same, right? Actually no. This lesson will examine different types of wind including the Chinook, a type of foehn wind, and the Santa Ana winds, a type of katabatic wind.
What is Wind?
Tonight on ‘Whirlwind Romance,’ we are going to interview two different types of winds in hopes of finding our eligible bachelorette, Marlie the Meteorologist, a match. Now a little on Marlie before we start. Marlie is trying to find a nice wind who can keep her warm at night, and as a meteorologist, Marlie studies the weather, so you can see why she is interested in dating wind!Before we bring out our two eligible wind bachelors, let’s explain what wind is and how it forms. Wind is simply air in motion that is caused by differences in pressure. Uneven heating of the earth causes this difference in pressure. Air that is colder is denser, thus creating greater pressure. If you take a look at this parcel of cold air, you can see that when more molecules are close together, they are going to bump into their container more often, which results in higher pressure.
And in this parcel of warm air, you can see that the molecules are further apart; therefore, it is less dense, resulting in lower pressure. Air flows from areas of high pressure to areas of low pressure, and this airflow is wind!I could go on and on, but our guests are becoming impatient, and we don’t want them to blow away and leave Marlie all alone! So, let’s bring out our first guest: the Chinook wind!
Welcome to the stage, Chinook wind. Now, Marlie can’t see you, but she will be able hear about you, so let’s get started!I understand that Chinook actually means ‘snow eater,’ so I’m guessing you are a warm wind that causes snow to melt? Yep, it sounds like it! So, on your bio it says Chinook winds are warm and dry foehn winds that blow down the eastern slopes of the Rockies.
These warm winds can be a brief reprieve from the cold, harsh winters found in the Canadian Rockies!But what in the world is a foehn wind? Well, Chinook winds are a type of foehn wind, and foehn is German and translates into ‘hair dryer.’ So, as you might expect, foehn winds are dry and warm winds that can be found on the leeward side of a mountain. Well, you might not have expected the leeward mountain bit but, like a hair dryer, foehn winds blow dry, warm air! And, by the way, the leeward side of a mountain is the side protected from the prevailing wind — so it’s usually the eastern side of a mountain because wind typically blows from west to east.In order to give Marlie some background information to ensure you’re the right wind for her, let’s learn a little bit more on how you form. I see here that foehn winds, like you, form when moist air hits a mountain. In your case, Chinook winds form when this moist air comes off of the Pacific Ocean and hits the Canadian Rocky Mountains. When this moist air hits the mountain, it’s forced upward where it starts to cool.
Now, as it cools, it reaches its saturation point, meaning the air mass can’t hold any more water vapor, so the water vapor starts to condense, forming clouds and precipitation, thus releasing the excess water. The air mass dries out, passes over the mountain peak and then slides down the leeward side of the mountain as dry, warm air.