Chapter 5 - Atmospheric Pressure Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is Atmospheric Pressure?

A

Changes in temperature leads to changes in pressure causing wind

Force exerted by weight of gas molecules on portion of Earth’s surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

3 Factors influencing atmospheric pressure

A
  1. Greater density
  2. Greater temperature
  3. Vertical movement of air
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Generalizations of surface pressure

A

High surface pressure = descending air (cold air)
Low surface pressure = ascending air (warm air)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is pressure gradient

A

Horizontal pressure change. a “slope”

winds going from high pressure to low pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Coriolis force?

A

Deflection of wind due to earth’s rotation.

Northern Hemisphere: deflecs to its right
Southern Hemisphere: deflects to its left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is friction?

A

Drag of Earth’s surface. Slows winds and reduces coriolis effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is wind speed and the type of gradients?

A

Determined primarily by pressure gradient.

Steep gradients generate faster wind speeds
Gentle gradients generate slower wind speeds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an anticyclone?

A

-HIGH PRESSURE
-sinking air (cold air)
-surface DIVERGENCE
-clear skies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a cyclone?

A

-LOW PRESSURE
-rising air (warm air)
-surface CONVERGENCE
-clouds, storms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are Hadley cells? and explain.

A

Tropical convection cells situated on either side of equator.

-warm air rises, air cools, air shifts poleward as antitrade winds (cool air)
-air descends around 30n/s forming high pressure
-diverging air from 30n/s known as trade winds (warm air)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 4 components of general circulation?

A
  1. Intertropical Convergence Zone (ITCZ)
  2. Trade Winds
  3. Subtropical Highs
  4. Westerlies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a subtropical high?

A

-Always near 30N/S
-descending air from hadley cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why is sth located over ocean basins?

A

Warm air from land rises (low pressure) and descends on the ocean (high pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a trade wind?

A

-Winds coming out of sth
-anticyclone
-between 25n/s
-wind is dry and warm from sth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Intertropical Convergence Zone (ITCZ)?

A

Zone of convergence of trade winds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is the ITCZ more pronounced over land?

A
  1. Land gets more heat compared to water
  2. as a result, warm air rises
  3. and clouds form
17
Q

What is a sea breeze? and explain

A

Daytime onshore winds

-water heats slowly during the day (because water is 5x slower to heat up)
-wind flows from higher pressure to low

(water being high pressure because it’s cooler)
(land being low pressure because it’s warmer)

18
Q

What is a land breeze? and explain

A

Night time offshore winds

-land cools off faster at night
-water takes 5x longer to cool
-land becomes high pressure (because it’s cooler)
-water becomes low pressure (because it’s warmer)

19
Q

What is Foehn/Chinook winds?

A

Downslope winds develop from pressure gradients over mountain barriers

Wind on the backside of the mountain.

Wind is warmer.

20
Q

What is a leeward flow?

A

Backside of the mountains. Flow is warm and dry (low pressure)

21
Q

What is windward?

A

Front of the mountain, cooler air (high pressure)

22
Q

What is santa ana winds?

A

Opposite of chinook winds.

Typically happens in mid latitudes (west to east)

Winds go from east to west (temporarily happens)

23
Q

What is el nino?

A

Temperature of the ocean and how the environment reacts to it.

-Eastern pacific water gets abnormally warm -> warm air rises -> storms and rains

24
Q

What is La Nina

A

Cooling of waters off South America

-Eastern pacific water gets cooler -> cool air sinks -> no rain = droughts

25
Q

Barometer

A

measures atmospheric pressure

26
Q

Millibars

A

unit of measure of force per surface area

27
Q

Isobars

A

isolines of equal pressure contours

28
Q

Ridge

A

elongated area of relatively high pressure area

29
Q

Trough

A

elongated area of relatively low pressure area