Chapter 5: Atmospheric Circulation and Ocean currents

Question 1

How does temperature affect air? 1) the warmer the air mass? (how dense) 2) Warming an air mass (add heat) does what (expand,density)? Cooling an air mass does what?

Answer 1

• The warmer an air mass - the less dense it is
  
  • Warming an air mass (adding heat) and it will expand (and since the density of the air mass is equal to its mass divided by its volume (p=mass/volume) its density will decrease
  • Cooling in air mass (extracting heat) will cause it to contract, so its density will increase, causing it to descend. It will sink

Question 2

Pressure effects on air?

Answer 2

• Compress air (increase pressure) (high pressure on a volume of air, will make it smaller) less pressure will allow air to expand –> the density of the air mass will also change in response to pressure

Question 3

Higher altitudes mean in regards to air?

Answer 3

the atmospheric pressure is lower (ex: top of a very tall mountain there is not much aire- the atmosphere gets thinner and thinner with increasing elevation - the air pressure up there is low)

Question 4

What does change in pressure mean in regards to air? Scuba tank example?

Answer 4

(not only air mass); but it also affects the temp of air mass undergoing the pressure change- because compressing an object will cause it to get warmer
- When volume of air descends and the pressure increases, it becomes compressed and gets warmer - or vice versa

Scuba tank: as air is forced into the tank, the air inside becomes not only denser, with more molecules being packed into the confiend volume of the tank, but also warmer - too hot to touch! – when we release it, the air will expand and cool, condensing

Question 5

Volume of air changing vertically?

Answer 5

when wind blows up a slope/hill
–> the atmospheric pressure surrounding the air mass decreases as it increases in elevation, which allows it to expand and therefore become cooler. And on the other side, the wind continues to blow, that same air will descend, contract into a smaller volume, and become denser again and as it does it will get warmer

Question 6

Humidity? What does warm air or cooler air mean in regards to water vapor?

Answer 6

how much water vapor is contained in a volume of air. Warmer air can hold more water vapor than cooler air - air that becomes less dense and vice versa- when water vapor sneaks into air, molecule of o2 or N2 in the air is displaced (both molecules are heavier than a water molecule)

Question 7

What balances the inequality in heating of the Earth’s surface?

Answer 7

there is a net energy transport mechanism at work
1) latitudinal heat pump
2) the major ocean currents

Question 8

What happens when water vapor (humid air mass) moves to higher latitudes?

Answer 8

it condenses and falls as rain, releasing its store of latent heat and warming the atmosphere there- this movement of water vaport transports heat to higher latitudes

Question 9

Atmospheric convection cells

Answer 9

if one air on one side of the box is heated, causing it to expand and rise, it will create an area of low atmospheric pressure on the bottom of the heated side of the box; the column of air on that side, having been heated and expanded, is less dense and therefore the column of air from the bottom to the top of the box weighs less. The air rises and is replaced by air that moves across the floor of the box. The rising air encounters the roof of the box and flows laterally across the top of the box. The continued heating of air on the warm side of the box, and then continued loss of heat on the opposite side, set up a circulation pattern of vertical and horizontal air motions that is a convection cell.

Question 10

How earth rotates how many times per day? what does this mean ?

Answer 10

It rotates at least once per day. This indicates that moving things from the North hemisphere experiences a tug -a deflection - to the right, while southern hemisphere experiences a deflection to the left (coriolos effect)

Question 11

Coriolis effect example:

Answer 11

You’re on the north pole, right? So now you want to throw something at Southeast Asia, from someone seeing it from the earth, the ball went in a graceful arc to the right, but to people out in space, that thing went straight (the deflection will be based off of how much the moving object curves, how fast the object is moving, hoe far the object travels over the moving reference frame)

north hemisphere, counter-clockwise, the ball is deflected to the right
southern hemisphere, clock-wise, the ball is deflected to the left

Question 12

Coriolis effect at equator vs the poles?

Answer 12

At equtor; very minimal
Pole; the coriolis effect is rapid

Question 13

coriolis effect north/south? Where else?

Answer 13

Also present in east-west; however, at one point the coriolis deflection would trace in a circular motion, bringing back the object back to its original place (called inertial oscillation)

Question 14

centrigual force? centripetal force?

Answer 14

the forces that tend to pull a rotating object outwards (greatest at the equator) This is basically when you swing a bucket on top of your head super fast, and bc it goes zoom the water stays in the bucket even if it is upside down- centrifugal hold water in, and centripetal force is our arms an equal but opposite force
-gravity essentially

Question 15

What pulls us to the center of the earth?

Answer 15

Centripetal force of the earth, pulls us toward the Earth’s center of mass, as shown by the dashed red arrow

Question 16

Northeast Trade Winds

Answer 16

Surface winds between 30N and the Equator will be unable to blow south to the equator -> gets blown to the right; same phenomenon in the Southwest Trade winds —> flipped flopped (northeast to southeast)

Question 17

Doldrums

Answer 17

Poor sailing conditions-> once winds from north/south approach equator they begin to rise vertically, retaining little or no horizontal motion

Question 18

Humid air expansion?

Answer 18

Rising air responsible for the clouds in the equator over the oceans; humid air expands, causing water vapor to condense, forming tune droplets of liquid water, form rain and clouds - only so high before it reaches troposphere, so it’ll start going to the right (north hemisphere) and left (if in Southern Hemisphere)

Question 19

Subtropical jet streams?

Answer 19

High altitude winds 30N and S; ribbon like winds that blow directly east (in each hemisphere) at very high speeds (order of 100 mph)

Question 20

Horse latitudes?

Answer 20

Where surface winds are weak: at 30N -‘d 30S, high altitude air has become dense enough, having cooled and lost humidity, sinking back towards the surface -causes high atmospheric pressure at the surface at 30N and 30S -cuz it’s low in humidity, then there’s very little cloud and precipitation there, and on earth it’s majors desserts, on ocean it’s horse latitudes

Question 21

Prevailing westerlies ?

Answer 21

30N and 60N; experience weather systems that cross the continent from the west

Question 22

Polar jet stream?

Answer 22

Found about 60N, similar to sub tropical jet stream, flows from west to east

Created: westerlies encounter cold air from the polar region and rise over it, all while deflecting to the right as that air ascends, creating another ribbon like, high altitude, high velocity wind, directly over the North Pole (cold and dry) sinks there and spreads to the South Pole Between 60N and North Pole; some mass has become warmed sufficiently that some air rises, but most of that still-cold arctic air cuts beneath the air flowing north, thus lifting that are to form the polar jet stream

Question 23

Three cells?

Answer 23

Hadley, Ferrel, and polar cells

Question 24

Cold dry land makes what? While warm water does what?

Answer 24

Cold dry land makes a cold, dry, air mass that is relatively dense, and a surface area of high atmospheric pressure. (Area of sinking air)

Warm water? Makes a warm and humid air mass, and a surface area of low atmospheric pressure (less dense, so it’ll tend to rise)

Question 25

Low pressure cells / low pressure forms what then?

Answer 25

Surface (ground level) areas of convergence (low pressure) that accompany warm and/or humid rising air, and areas of divergence (high pressure) of cold, dry, descending air (this is what caused high and low pressures) -once low pressure is established, the air rushing to replace air will begin to encircle the low pressure, bc of Coriolos effect, creating a counterclockwise rotation of winds around the low

Question 26

High pressure forms?

Answer 26

Relatively dense air (dry and cold) falls and spreads laterally at the Earth’s surface, giving a clockwise rotation around the high

Question 27

Low