Part 3 – Thermal Winds
Since kitesurfing is a wind driven sport it is important to understand and be able to read the wind.
When you come to Squamish kite surfing the first thing you are going to notice is that we in Squamish kite right between the mountains. Your usual kitespots are normally located at a beach or a big lake.
So how does it work kiting between mountains and how does it affect the wind?
What makes Squamish kite surfing possible and so special is the thermal wind here. Before we get to that, though, we talk about how thermal winds work in general.
The thermal wind is set up by a change in temperature over a change in distance. As we already know, differences in temperature cause differences in pressure and Mother Nature always tries to balance out these differences. With the wind flowing from high pressure into low pressure, the thermal wind flows parallel to the temperature gradient (from the colder area to the warmer area).
As kitesurfers we most often experience thermal winds in form of a sea breeze.
Since the sea has a greater heat capacity than land, the surface of the sea warms up slower than the surface of the land. With the temperature of the surface of the land rising, the land heats the air above. The warming air expands and becomes less dense, decreasing the pressure over the land near the coast. The air above the sea has a relatively higher pressure, causing air near the coast to flow towards the lower pressure over land.
The strength of the sea breeze is directly proportional to the temperature difference between the land and the sea. The bigger the difference in temperature, the stronger the sea breeze.
Mountain and Valley Wind
Another example for thermal winds, are the mountain wind and the valley wind.
Forming through a similar process to the Sea breeze, the mountain and valley breeze are two related localized winds that occur one after the other.
The mountain and the valley breeze are opposite to each other.
During the day, the sun heats up the mountain air rapidly while valley remains relatively cooler. The difference in the density of the air causes it to rise, causing a valley breeze.
At night, the process is reversed. During the night the slopes get cooled and the dense air descends into the valley as the mountain wind
Now that we understand the 3 different types of wind we can have a look at how that affects us in Squamish kite surfing.
Check out the article ‘Kitesurfing in Squamish – understanding the wind’