Atmosphere

Question 1

Composition of Atmosphere

Answer 1

Nitrogen 78%
Oxygen 20%
Other gasses 2%

Question 2

Troposphere

Answer 2

• between surface & 8 - 18 km
• Varies in depth -> twice as high over equator (60,000 ft) compared to poles (30,000 ft)
• First layer of Earth atmosphere - Temp drops w increasing height
• Contains atmospheres convection, water vapour, weather & clouds

Question 3

Tropopause

Answer 3

• Temp lapse rate changes
  -> air no longer cools w hight
• Marks point where convection from

Question 4

Stratosphere

Answer 4

• Temp starts to increase w hight (gets heated by radiation it absorbs)
• Very little vertical mixing of air
• Only clouds found here are TCU or CB

Question 5

How much water vapour in atmosphere

Answer 5

minute traces to 3% of total mass

Question 6

Stratopause

Answer 6

• Above stratosphere
• abrupt temp change

Question 7

Temp lapse rate

Answer 7

-2’C / 1000 ft

Question 8

Pressure lapse rate

Answer 8

-1 hPa / 30 ft

Question 9

Standard atmospheric temp

Answer 9

15’C

Question 10

Standard atmospheric pressure

Answer 10

1013 hPa

Question 11

Whats lighter

Warm air
or
Cold air ?

Answer 11

Warm air
-> in atmosphere warm air rises & meets cooler air
-> air keeps rising until same temp as environment around is same temp

Question 12

Why is the equator hotter ?

Answer 12

Given amount of Solar Radiation is spread over smaller area near equator compared to larger amount at poles

Question 13

How is heat transferred to the lower layers of the atmosphere ?

Answer 13

Conduction
-> heated air rises
-> pushes cold air down

Question 14

What altitude is the Ozone layer ?
What does the Ozone layer do ?

Answer 14

50 km above surface

Ozone absorbs large amounts of solar Radiation

Question 15

What happens with incoming Solar Radiation ?

Answer 15

• Ozone Layer absorbs large amounts
• Some reflected back into space (Cloud tops)
• Some scattered by particles in air (giving sky blue colour)
• Absorbed by land surface

Question 16

What are the layers of the atmosphere ?

Answer 16

Exosphere
- Thermosphere
Mesopause
- Mesosphere
Stratopause
- Stratosphere
Tropopause
- Troposphere

Question 17

What layer of the atmosphere has increasing temp with increasing hight ?

Answer 17

Stratosphere

Question 18

Pressure Height Formula

Answer 18

ELV + (1013 - QNH) x 30 = PH

Question 19

ISA Temp Formula

Answer 19

15 - ( 2 x thousands of ft ) = ISA Temp

Question 20

Density Height formula

Answer 20

ISA dev x 120 + PH = Density Hight

Question 21

ISA Deviation Formula

Answer 21

Outside temp - ISA Temp = ISA dev

Question 22

Stable atmosphere =

Answer 22

Air STOPS rising or sinking on its own

Question 23

Unstable atmosphere =

Answer 23

Air CONTINUES to rise & sink on its own

= Greater Environment Lapse Rate
-> Warming of lower levels of environment
-> Cooling of upper levels

Question 24

What effects the stability of the atmosphere ?

Answer 24

the way Temp behaves both inside & outside the parcel

The Environmental Lapse Rate determines stability

Question 25

What is an Adiabatic Process ?

Answer 25

one which temp changes without any heat transfer It changes temp through compressing air - Heat is squeezed into smaller volume = hotter Heat expanded into larger volume = colder

Question 26

What is the Dry Adiabatic Lapse Rate (DALR) ?

Answer 26

1) Air rises & cools by expansion -> no cloud forms 2) This expansion causes adiabatic cooling of the parcel Usually -3'C / 1000 ft

Question 27

What is the Saturated Adiabatic Lapse Rate (SALR) ?

Answer 27

1) Air rises & cools -> Cloud forms 2) Latent Heat released 3) Slows down Adiabatic cooling rate - Rate of condensation (release of latent heat) is greatest near cloud base - SALR increases from base -> top of CLD Usually -1.5'C / 1000 ft

Question 28

Conditional Instability

Answer 28

When the ELR is between DALR (3'C/1000ft) & SALR (1.5'C/1000ft) The Atmosphere will be : -> Stable when there is no cloud -> Unstable when there is cloud Unstable for cloud because -> Latent heat released -> reduced cooling of air in cloud -> increasing temp difference between cloud & environmental air

Question 29

What weather does Conditional Instability produce With Cloud = & No Cloud =

Answer 29

With Cloud = TCU & TS No Cloud = mod turbulence

Question 30

If the ELR is below 1.5'C / 1000 ft Is the atmosphere stable or unstable ?

Answer 30

Totally stable

Question 31

What is a high ELR ? What is a low ELR ?

Answer 31

HIGHT = Environment cooling rapidly w hight = unstable LOW = Stable