Vortex, Von Karman Effects

A Kármán vortex street is 

a repeating pattern of swirling vortices caused by the unsteady separation of flow over bluff bodies. They are named after the engineer and fluid dynamicist, Theodore von Kármán. 

Relative motion between an object and a fluid is common occurrence. Simple examples are the motion of a plane in flight or the wind blowing on an obstacle. 

Obstacles disturb the flow and create particular shapes in their wakes. This phenomenon can be easily observed behind piers of a bridge, where eddies appear and are blown by the stream.

Here at the Mayon Volcano in the Philippines. 

Took this picture last week:

 When a vortex is shed, an asymmetrical flow pattern forms around the body, which therefore changes the pressure distribution.

 Old lave stream. 
West side of Mayon. 
Unfortunately Mayon was already hazy at this time of the day. 
HDR didn't help either.

Well, upon request two HDR's, not really my style. 
Have overdone it a bit on purpose:

(No HDR)

Pose at Legaspi Boulevard