Temperature

Question 1

Celcius vs Farenheiht

Answer 1

Celcius is based on:
Water freezing at 0 degrees and boiling at 100 degrees

Farenheiht is based on:
Water freezing at 32 degrees and boiling at 212 degrees

Use your E6B to convert from one to the other. Don’t use this on the exam but you can roughly convert C to F by doubling the degrees in C and adding 30. Its sort of accurate

Question 2

What are the two main ways the atmosphere is heated?

Answer 2

• Terrestrial radiation: the earth absorbs short-wave UV radiation from the sun and spits it back out as a much longer wave-length radiation (infra-red radiation).
• Conduction

It is through the combined effects of the terrestrial radiation and conduction that the lowest levels of the atmosphere are heated from the bottom up

Question 3

What is conduction heating?

Answer 3

• Short-wave UV Radiation is absorbed by the earth/bodies of water and is re-radiated back out at a much longer wave-length IF Radiation.
• Water and water vapour is very good at absorbing IF radiation and holding that heat in the atmosphere. This is much more effective near the surface of the earth where molecules are densely packed.

Question 4

What four types of heating variations are there?

Answer 4

• Diurnal (the difference in temps between night and day)
• Seasonal
• Lattitude (equater is closer to the sun and gets hit directly by it, vs the poles and strikes the poles at an angle)
• Topography

Question 5

In terms of diurnal variations, what happens during day and night?

Answer 5

Day:

• As sun rises it heats the air
• As the air heats, it rises, causing general mixing in which the faster moving air aloft if pulled down to the surface and the lower surface air is pushed aloft.
• This causes the surface wind to increase in speed and veer in diretion

Night:

• After the sun goes down the earth gives off a lot of the energy it absorbed from the sun during the day
• This will lead to cooling
• This will cause surface winds to decrease in speed and back in direction at night

**These diurnal variations do not occure over large lakes and oceans because water retains the suns energy and does not re-emit it, causing cooling

Question 6

What causes seasonal variations in heating?

Answer 6

Due to the axial tilt of the earth, it changes the angle the sun strikes the earth in any given season. As well as for how long it strikes the earth for in a given day.

Question 7

What causes Lattitude Variations in heating and cooling?

Answer 7

• Related to seasonal variation but not directly
• At the equator the sun strikes directly and has a much deeper atmosphere to hold re-radiated heat**
• A more Northern and Southern latitudes the sun is off at an angle, resulting in energy being spread out and less direct/strong

Question 8

What effects does topography have on heating and cooling?

Answer 8

• Land surfaces soak up solar radiation much quicker than oceans or lakes (land heats up faster that water)
• But land is also quicker to release that heat. During the night or winter a lake or ocean will stay warmer longer than the land will
• Vegetation and soil type can also significantly change the mount of heat that is absorbed

Question 9

What methodes move the air around the atmosphere? (6)

Answer 9

• Convection
• Advection
• Conduction
• Latent Heat
• Compression
• Turbulent mixing

Question 10

What is Conduction heating?

Answer 10

Conduction: The transfer of energy, such as heat or an electric charge, through a substance.

UV Radiation strikes and is absorbed by the earth. The warmed earth then re-emits that heat as long-wave IF radiation and heats the air directly above it. The air that is touching/in contact with the earth

Question 11

What is convection heating?

Answer 11

As the air that is in contact with the earth is warmed via conduction heating, it then becomes less dense and rises (called thermals). This allows cold air to sink and replace it. This cold is is then heating by the earth and rises. Etc, etc.

This is convection heating

Also happens in winter, when cold air moves over open water, which retains heat well

Question 12

What is advection heating?

Answer 12

Advection: the transfer of heat through the horizontal movement of air.

Heavier, denser air shoves in to warmer thinner air, pushing the warmer air up. The cooler air then gets warmed by the earth.

Question 13

What is latent heat?

Answer 13

• Heat that is ‘hidden’ in water vapour
• They will hold this heat until they are forced by some process to cool down, usually via rising
• As it cools, it condenses, releasing that heat that was absorbed nearer to the surface of the earth, into the atmosphere and heating the surrounding air

Question 14

What is compression heating?

Answer 14

When a large parcel of air sinks or subsides, it is compressed by the increasing air pressure of the lower atmosphere.

This increase in pressure will result in the air warming up

Question 15

What is turbulent mixing type heating?

Answer 15

Turbulence caused by friction between the air and ground will create eddies in an up and down motion. This will allow warm air near the surface to be lofted into the atmosphere

Question 16

What are the three major ways the atmosphere can be cooled?

Answer 16

• Radiation (the heat the earth absorbed during the day gets radiated back out during the night)
• Advection (air over a snow covered field moved over to a warmer spot of a ploughed field or something)
• Adiabatic Cooling (sometimes related to convection. As rising air expands, it cools. Basically its just rising air gets cooled)

Question 17

What is radiation cooling?

Answer 17

Heat absorbed by the earth during the day gets released back into the atmos and then on back in to space during the night.

This type of cooling typically does not affect anything beyond a few thousand feet abive the surface

Layers of cloud or water vapour can trap this heat before it gets too far, holding the heat at altitude. This is called an inversion

Question 18

What is adiabatic cooling?

Answer 18

• Any time air rises, it will start to expand, which leads to cooling
• The cooling happens at different rates depending on whether the air is saturated or not
• If the air is not saturated (no visible moisture yet) then it will cool at the Dry Adiabatic Rate of 3°C / 1000ft)
• Once the air becomes saturated it will cool at 1.5°C / 1000ft)

Question 19

What is the Environmental Lapse rate?

Answer 19

The actual observed change in temperature with an increase in altitude (instead of the ISA 1.98oC/1000ft). Changes constantly.

Question 20

What is an inversion?

Answer 20

This is where the temperature of the atmosphere increases with an increase in altitude

Question 21

What are the effects of an inversion on weather?

Answer 21

• Air is very stable (because the warm ‘cap’ stops any more rising)
• During a low-level inversion, if the humidity is high, expect smooth air and poor vis due to haze/fog/stratus cloud
• Wind shear often exists if a strong inversion is encountered after takeoff or during approach

Question 22

What are isotherms and isothermal layers?

Answer 22

Isotherm: Lines joining areas of equal temperature on a map

Isothermal Layer: This is when temperature remains the same at different altitudes. Like an inversion it causes very stable air

Question 23

Quiz Question:
A significant inversion at low height is a chracteristic of:

Answer 23

Nocturnl Radiation

Question 24

Quiz Question:
Horizontal differences in the mean temperature of a layer are caused by:

Answer 24

Differential heatin gof Earth’s surface?

Question 25

Quiz Question:
A common location for an inversion is:

Answer 25

in the stratosphere

*The tropopause was an option but was not the correct answer becaue temperature is more or less stable within the tropopause. It only starts to climb once within the stratosphere