Lecture 7: Pressure & Wind

Question 1

What happens when a gas is heated

Answer 1

expanded, lower density

Question 2

What is the relationship between temperatures, density and pressure?

Answer 2

If you change one variable at least one of the others must respond

(ideal gas law)

Question 3

What is air pressure?

Answer 3

Force exerted on an object

Average sea level pressure: 29.92 inches

Question 4

How does air pressure change vertically and horizontally?

Answer 4

Pressure gradient force causes horizontal pressure differences and winds
Gravity caused vertical pressure differences and winds

Question 5

How does air pressure cause horizontal motion?

Answer 5

denser packing of isobars = faster wind and small difference in pressure = slower wind

Question 6

How does air pressure cause vertical motion

Answer 6

gravity pulls molecules towards earth’s surface, making pressure greater near surface

depends on temperature

Question 7

Pressure gradient force

Answer 7

air is always going to move from an area of high pressure to low pressure

Question 8

Gradient force

Answer 8

the change in pressure measured across a given distance

Question 9

Convergence

Answer 9

occurs when wind moves towards a region such as a in a low pressure system

Question 10

Divergence

Answer 10

occurs when horizontal winds cause a net outflow of air from a region

Question 11

What happens when a gas is cooled?

Answer 11

compressed, higher density