Chapter 4 pt 4 Flashcards Preview

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Flashcards in Chapter 4 pt 4 Deck (35)
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1

Transmission

Energy passes uninterrupted through the atmosphere or water

2

Energy Budget

a balance between shortwave energy received and longwave radiation lost

input (shortwave) – output (longwave)

3

Scattering is the:

physical interaction between incoming radiation and:

- Atmospheric gases
- dust
- cloud droplets
- water vapour
- pollutants

redirection without changing wavelength

4

Why is the sky blue?

- Violet and blue light: shorter wavelengths (scatter first)

- Red and yellow light: longest wavelength (travels the farthest)

- when light hits a gas molecule in our atmosphere, it is absorbed

- high frequency blues and violets get absorbed more
- the gas molecule then radiates the light in different directions (colour that was radiated is the same colour that was absorbed)

(Raleigh scattering)

5

Why is the sunset red?

- when the sun sets its further away from you
- the path to get to your eyes is longer, therefore the chance of the longwave red and yellow light hitting gas molecules is higher
- the light also travels through the lower atmosphere, which has a greater concentration of particles
- these particles reflect the light that hit them

6

Mie Scattering

The larger particles in the atmosphere (larger than the wavelengths of light) cause the sky to appear white
(haze, pollution)

in a very hazy/polluted area, all wavelengths of light are scattered evenly, making the human eye perceive it as white

7

Refraction

Bending of light resulting from a change in medium.

Insolation entering the atmosphere changes mediums. this causes a shift in speed and causes the light to bend (shift direction)

8

Albedo

(reflectivity of an object). the percentage of insolation that is reflected

9

Absorption

the assimilation of radiation by molecules of matter, converting the radiation from one form of energy to another

10

Clouds reflect ____

shortwave radiation

11

Clouds absorb _____

longwave radiation

12

Longwave radiation is absorbed in the atmosphere by:

carbon dioxide
water vapour
methane
nitrous oxide
chlorofluorocarbons (CFCs)

13

Cloud albedo forcing

Low, thick stratus clouds reflect about 90% of insolation

High-altitude, ice-crystal clouds reflect only about 50%

14

Cloud greenhouse forcing

Clouds, mainly high-altitude, ice-crystal clouds trap longwave radiation emitted from earth

15

Jet contrails create...

condensation trails that produce high cirrus clouds, which trap more radiation than it reflects.

16

Energy budget between the tropics

Energy surplus

17

Energy budget at the poles

Energy deficits

18

Daily Radiation Patterns

Maximum daily temperature lags by several hours (~3:00-4:00 pm)
Due to time it takes for energy to transfer (nonradiative & radiative)

19

Boundary layer

the lower atmosphere at the Earth’s surface where energy and moisture are continually exchanged

20

Microclimates (smaller than Boundary Layer Climates)

are local climate conditions over a relatively small area (i.e. parks, or parking lots)

21

Net radiation

the sum of all radiation gains and losses

- positive during the day
- negative during the night

22

Non-radiative ways to lose heat

3 WAYS

1. Latent heat of evaporation
2. Sensible heat
3. Ground heating and cooling

**

23

Urban Heat Island

An urban micro-climate that is warmer on average than areas in the surrounding countryside due to interaction between solar radiation and various surface characteristics

24

heating is increased by modified urban surfaces:

(6)
asphalt
glass
building geometry
pollution
human activity
industry and transportation

25

Earth emits...

Longer wavelengths

26

The sun emits...

Shorter wavelengths

27

What happens to incoming radiation? (4)

Reflection
Scattering
Refraction
Absorption

28

Earth's average albedo

31%

29

The theory behind why the sky is blue is called

Raleigh Scattering

30

Atmospheric Window

?