What causes turbulence during a flight?

Question

What causes turbulence during a flight?

Answer 1

the fat woman sitting in 1st class

Answer 2

The air above us moves in many different directions. At one point it might be moving slowly west; a few thousand feet above that point, or a few thousand feet away from it laterally, it might be moving in a completely different direction.  It's rare for all of the air everywhere in a region to be moving in the same direction, at the same time, at the same speed.

Airplanes fly through the air.  Not only do they move through the air on their own, but if the air itself is moving, the airplane moves with it.  So if an airplane is flying forward through air that is slowly rising, the airplane will slowly rise, too, in addition to moving forward.

If an airplane flies from one air mass that is moving one way into another air mass that is moving a different way, the airplane will shift slightly as it flies.  If it goes from an air mass that is drifting west into an air mass that is drifting east, it will shift towards the east as it moves between the air masses.  Often this shift happens quickly enough that it can be felt inside the airplane.  When the airplane moves quickly, it is felt by passengers as turbulence.

Since airplanes fly very quickly, they can move from one air mass to another very rapidly.  If the air masses are moving in different directions, the airplane will bounce around as it moves from one air mass to another.  It doesn't hurt the airplane and it isn't dangerous, but when there are many air masses moving many different ways, it can feel like a roller-coaster at times.

Think of a car on a hilly road.  If you drive the car slowly, you don't notice it much when you go down one hill and up another.  If you drive faster, however, the car will zoom up and down as you move from one hill to the next.  An airplane flies ten times faster than a car, so when it moves from one air mass to another, it can move quite rapidly up, down, right, or left.  When it is really bounced around, that's turbulence.

Often turbulence is associated with cloudy weather, since clouds tend to have lots of updrafts and downdrafts, and they themselves are often associated with different air masses coming together.  Sometimes turbulence occurs in clear air, because one air mass is moving rapidly one way, and another is moving a different way, and the air churns around wherever they meet.  As an airplane passes between the big air masses, it bounces around where they are churning.

Turbulence is nothing more than the airplane equivalent of bumping around on a hilly or twisty road in a car.  Since planes fly fast, sometimes the bouncing is a lot more dramatic than it is in a car, but it's still not dangerous.

Answer 3

Pressure differences caused by uneven heating of the earth which cause high and low pressures.

The high pressure air is diverging air, or spreading out, while the low pressure air is convering.  Nature is always trying to enter a state of equilibrum, thus the air flows from an area of high pressure, to a low pressure, thus creating air flow, or wind, which can cause turbuelcence.

Another factor is rising and decending air. this is from two parcels of air with differnent temps (warm air is less dense then cold air and vice versa). The hot air will rise, and cold air will sink, creating up and downdrafts, aka turbeucle, which is why flying in thunderstorm can be very dangerous- disregarding hail and lighting.

Another form of turbuelnce is a air that is forced to ascend a mountain range, and made unstable by the lifting over the mountain, which can produce mountain waves.

Answer 4

Simple answer is the uneven movement of air.  Air behaves just like a liquid.  Let's use the ocean for example...you get waves due to currents, winds, etc.  In the air, you get "waves" too, but they are caused by air masses of different characteristics colliding, uneven heating, winds, etc.