TURBULENCE Flashcards
Convective (thermal) turbulence
Caused by unequal heating of the earths surface. Darker areas such as soil, rocks, sand, heat up faster than lighter areas, such as grass, or water.
G. F. A.
Graphical forecast area
Mechanical turbulence
Caused by friction between the air and the ground. It is also created when wind, encounters trees, or man-made objects like buildings.
Frontal turbulence and shear
Caused by the friction that occurs between two opposing air masses. More commonly associated with cold fronts, but it can occur with warm fronts.
Orographic turbulence
This is caused by friction in air currents through a mountainous region, as the air moves up mountains or hills.
Tip
Always cross ridges at 45° angle and at more than 2000 feet
Mountain wave turbulence
Air flowing across a mountain range, usually rises relatively smoothly up the slope of the range once over the top, it pours down the other side with significant force.
Wind shear
A sudden change in wind, speed, and/or direction in a short distance, resulting in a caring or shearing effect
What are some causes of windshear?
Microbursts (Virga-possible indication)
Jet streams
Typography
Fast moving Fronts
Types of wind shear
Speed shear – wind blowing at different speeds at different altitudes creates turbulent, Eddie’s
Directional, shear – wind blowing in different directions at different altitudes creates turbulence
Low level, wind, shear:
A significant non-convective windshear that could adversely affect aircraft operation within 1500 feet AGL over the Aerodrome
What is the main effect of wind shear?
The rapid gain, or more critically a loss of airspeed
Wind shear- Virga
Rain that falls dragging cold Dense air along with it
VIRGA
Virga hazard, strong downdrafts
