Atmospheric Composition and structure Flashcards Preview

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Flashcards in Atmospheric Composition and structure Deck (25)
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1

How much of the Earth's mass is contained in the atmosphere?

0.0001%

2

What are the permanent gases?

- Nitrogen
- Oxygen
- Argon

3

Nitrogen makes up how much of the atmospheric composition?

78%

4

Oxygen makes up how much of the atmospheric composition?

21%

5

Argon makes up how much of the atmospheric composition?

0.93%

6

Nitrogen, oxygen, and argon make up how much of atmospheric composition?

99.93%

7

Variable gases include:

Water vapour (0.25%) carbon dioxide (0.037%), ozone (0.01%), methane (1.7ppm)

8

Aerosols:

small solid particles or liquid droplets in the air

9

Aerosol sources and effects:

- wind generated dust
- volcanic eruptions
- sea spray
- combustion by-products

10

Aerosol effects:

- reduce visibility
- health effects
- formation of cloud droplets
- RADIATIVE EFFECTS (Climate
Change)

11

Troposphere

- adjacent to surface
- vertical decrease in
temperature (-0.6°/100m)
- generally well mixed
(convection and friction)
- contains almost all of atmospheric water vapour
- all ‘weather phenomena’
take place within this
layer
- average barometric
pressure at sea level:
1013 hPa

12

Tropopause

- top end of troposhere
- start of temp. inversion
- avg. barometric pressure: approx. 225 hPa (75%)
- avg. altitude dependent on
latitude
- Poles: ~ 8km
- Equator: ~ 17km
- avg altitude dependent on
season:
Minimum: winter – spring
Maximum: summer - fall

13

Stratosphere

- bottom half: isothermal
top half: temp. inversion
+0.25°/100m
- ozone layer (≤10ppm):
absorption of harmful UV radiation by O3
- geographic and spatial
variability of ozone
concentration and temp.
- water vapour content
extremely low
- very little cloud formation

14

Stratopause

- top end of stratosphere
- end of temp. increase
- avg. altitude: approx. 50km
- avg. barometric pressure:
≤ 1hPa (99.9%)

15

Mesosphere

- temp. decrease with
height
approx. 0.2-0.3°/100m
- vertical mixing possible

16

Thermosphere

- 85 – 800km
- continuous temp. increase due to absorption
of UV radiation
(difference between
temperature and heat)
- consists primarily of
molecular and atomic
oxygen and nitrogen

17

Isobars

lines that connect all points with same pressure

18

Wind moves from ___ pressure to ___ pressure

high to low

19

what does wind speed depend on?

the pressure difference - greater the difference, the faster the wind

20

wind rises in ____ pressure and sinks in area of _______

rise in low
sink in high

21

a rise in low pressure creates...

clouds

22

a sink in high pressure makes...

clear skies

23

Ideal gas law:

describes relationship between pressure, density, and temperature

24

Pressure ____ with increasing height. Why?

decreases because as altitude increases, the number of air molecules decrease.

25

When depth decreases, pressure is _____.

Reduced because the deeper you go under sea, the greater the pressure of the water pushing down on you is