Friday 2 August 2019

Does it get windier when a cloud blocks out the Sun?


On Porthcressa beach St Marys I once again noticed that it seemed to get windier on a hot sunny day when a cloud moved across the Sun temporarily. In the photos, the land near the beach was in shade and the beach itself was still in sunshine. In theory, there would be a drop in the upwards convection current from the nearby land shown in the top picture compared to the beach. This would mean that the land in the shade would have higher pressure air at ground level and thus a flow of air would occur from shaded area to sunlit. The Internet is divided about whether or not this effect is real but this isn't the first time I've experienced it.