On 08/24/2018 06:55 PM, Martin Gregorie wrote:

Judging by an article by Jean-Marie Clement in Sailplane & Gliding (Dec/
Jan 18 p40) the Perlan Project may have missed the boat for setting a
properly high record. M. Clement says that climate change has stretched
the Andean wavelength by causing and increase in wind speed, so it is no
longer in phase with the mountain topography. This weakens wave lift
while the increased wind speed has also reduced the duration of weather
cycles. He talks about having to accept 2-3 m/s wave climbs in 2017 where
a decade ago they'd have had 5-8 m/s, but adds that the vertical velocity
in hydraulic jumps wasn't affected though the jumps may have become more
frequent.



https://www.youtube.com/watch?v=I-cZzVA0Gcc