About

• Turbulence means disruption of airflow over the wings of an airplane, which causes it to enter irregular vertical motion.

Kinds of Turbulence

• Wind Shear: It happens when there is a sudden change in wind direction, whether vertically or horizontally. Typically occurs close to thunderstorms, jet streams, etc.,
• Frontal: It is created in the frontal zone when warm air is lifted by sloping frontal surface and friction between opposing air masses. Its intensity increases with thunderstorms and is most common close to thunderstorms.
• Convective: When land surface temperature rises, the air above the ground heats up and rises, creating air pockets around it. Convection currents cause difficulties during approach as they tend to affect the rate of descent.
• Wake: It forms behind an aircraft when it flies through air-creating wingtip vortices. It can be dangerous for small aircraft following bigger ones.
• Mechanical: This type of turbulence occurs when tall solid objects such as mountains or highrise constructions disrupt the normal airflow, causing the air for planes to fly through to become dirty.
• Clear Air: This type occurs when an aircraft crosses from one air mass to another, which has a different direction. Clear air turbulence could also happen when an aircraft moves out of a jet stream. Clear air turbulence is mainly caused by wind or jet streams.
• Mountain Wave: It is one of the most severe types of turbulence. These are oscillations that form on the downwind side of mountains when strong winds flow towards mountains in a perpendicular fashion. 

Source

• https://indianexpress.com/article/explained/severe-turbulence-singapore-airlines-flight-9342878/