The article presents a new method to study how wind farms affect the wind flow. The researchers found that wind farming mainly affects the lower part of the boundary layer for wind speed changes and the upper part for wind direction changes. The thinner the boundary layer or the rougher the surface, the more the wind direction changes. Near a 5 MW wind turbine, the wind speed decreases by about 5%, the wind direction changes by 1-2 degrees, and the wind recovers after 20 rotor diameters. For a wind farm with 22 turbines, these numbers increase to 15% wind speed decrease, 2-3 degrees wind direction change, and recovery after 2 wind farm lengths.