Meteorology 8

Turbulence

Convective Turbulence Different surfaces on the Earth heat /cool at different rates, so some surfaces will give off more eat than nearby surfaces resulting in thermals and convective turbulence. Convective turbulence can be quite severe near the ground on hot days and its biggest impact is sudden upward or downward movement of the RPA. Avoidance: recognize when your RPA will be flying over a new type of surface, especially asphalt and water be especially vigilant on hot afternoons when there has been a long period of ground heating

Mechanical Turbulence When obstacles usually large man-made obstacles like buildings, impede the wind, they generate eddies currents on the leeward side. These eddies can rapidly change direction leading to very unpredictable wind gusts. Winds gusts and eddying are very common among large buildings. Its biggest impact is sudden change of wind direction and significant turbulence Avoidance: make note of wind direction and location of large obstacles avoid flying close to large buildings - especially between buildings and on leeward side

Orographic Turbulence Occurs on the leeward side of hills or mountains as a result of the air being disrupted by the hill or mountain. Be very aware of possible turbulence when flying on the leeward side of mountains or canyons as they can cause sudden upward or downward movement of the RPAS Avoidance: avoid flying very close to the leeward side of mountains