Lenticularis
Constant foehn processes on the eastern slopes of New Zealand's Southern Alps cause high temperatures and the exceptional high number days with sunshine. This causes a semiarid climate predominated by Tussock grass. Further indications of the foehn are the lee waves in the atmosphere that appear as lenticularis clouds. The air stream passing the mountain chain is forced into a high speed vertical wave motion. At their wave crests the air instantaneously condensates forming the spectacular foehn clouds.
March 2001
Pentax MZ5, Pentax 28mm, f/8, 2sec, Kodak Ektachrome E6, ISO 100, polarization filter, tripod