I love the idea that those grass skiers
were having fun but, being very familiar with golf course turf and other grasses, please stress to your public that this is never a good practice!
When any force or stress is put on nearly frozen turf, the results are that it immediately kills the grass underneath. I would suggest asking around to others who know about turf to see if what I'm telling you rings true to them. If we skiers want to keep enjoying the priviledge to ski on golf courses without repurcussions from course owners and staff, please advise against this. Yes, we skiers are desperate for good winter snow but this is not the solution.
The best thing to do is wait until the turf is sufficiently covered with enough snow to insulate it from stress caused by walkers, runners and skiers and that the ground is sufficiently frozen underneath. This usually takes effect when at least 2 or more inches have fallen and remains there for at least 24 hours. If snow falls to this depth and sticks around (because of good, low air temperatures), the ground underneath should shortly become frozen and safe.
I realize that even though their skis were not getting gunked up with grass and mud, they thought it safe to ski. I don't think they realize the slightest damage to a nearly frozen turf will kill it. This has been my experience working at a few golf courses and other places working as a landscaper.
Thanks for your time. Bye for now!