The effects of heat and sunlight are laid out in a study by the Department Of Homeland Security. Although not yet peer reviewed their findings seem to be fairly clear that direct sunlight is very good at Coronavirus. They found that direct sunlight reduced the half life of aerosolized Coronavirus from an hour to just 1.5 minutes, and from between 1 and 18 hours to just 2 minutes when on a mettle surface. This is just the half life but it is clear that outdoor activity with plenty of sun and ventilation are some of the safest. Lucky for us soaring (at least in a single place ship) falls right into these categories and thus in my opinion is one of the safer activities we can do as long as take proper precautions when rigging and landout.