July 8th, 2012
Lately I’ve been fascinated by orographic clouds – which are clouds created by Earth’s terrain forcing large amounts of air up into the atmosphere. You can think of these clouds as the result of a speed bump that these mountains create for air as it moves over Earth’s surface.
The reason this phenomenon occurs is due to an interesting way that air “cools” when it is moved up in the atmosphere. It is called adiabatic cooling which occurs when the pressure around the air decreases rapidly and the actual temperature of the air itself remains unchanged. Interestingly, if the opposite were to occur – where the pressure increases – the air would be “heated”. This is one of the principles that govern the way the engines in our cars work.
Browsing around the web you can find tons of photos of orographic clouds happening all over the world with stunning results. These clouds ended up on my radar because of this video from these clouds happening in the Wicklow Mountains in Ireland.
Living in the fairly rough terrain of north eastern Pennsylvania it will now be my own personal pursuit to find this happening in my area and capture it.