Any one have a degree in aerodynamics?
In a glider,
Moist air, less dense=less drag, less dense=less lift. Which has the biggest effect? I would guess the reduction in lift generated would be greater than the reduction in drag leading to an increase in rate of decent.
However it is 20 years since I did my ATPL written exams, 30 years since I studied A level physics and I do not have a degree in aerodynamics.
Interesting but the effect of moisture content of air on lift/drag is probably irrelevant in this unfortunate incident.