Friction between the atmosphere and the Earth's surface causes a 20% reduction in the wind at the surface of the Earth.[10] Surface roughness also leads to significant variation of wind speeds. Over land, winds maximize at hill or mountain crests, while sheltering leads to lower wind speeds in valleys and lee slopes.[11] Compared to over water, maximum sustained winds over land average 8% lower.[12] More specifically, over a city or rough terrain, the wind gradient effect could cause a reduction of 40% to 50% of the geostrophic wind speed aloft; while over open water or ice, the reduction is between 10% and 30%.[8][13][14]
The Johnson Family is planning a couple of excursions next week. On Wednesday they will be going to Tulsa Valley, and on Friday they are going to Albert's Peak, a small mountain in the area. Mr. Johnson has been wanting to fly some kites if there are some good wind conditions for doing so. He also wants to treat his family to a picnic and would like a more serene setting, with little to no wind to disrupt their picnic.
Which place will more likely be less windy?