lecture 4

Question 1

what is climate driven by?

Answer 1

Climate is ultimately driven by incoming and outgoing solar radiation (earth’s energy budget)

Question 2

what does the atmosphere determine?

Answer 2

• What hits the earth is determined by the atmosphere
  ○ Nitrogen
  ○ Oxygen
  ○ Argon
  Co2

Question 3

what do aerosols change

Answer 3

Aerosols change the long term pattern of atmosphere and climate

Question 4

sea level vs atmosphere spectrum of solar radiations

Answer 4

• Holes in the sea level graph are from components of the atmosphere
  Ozone is the balance between uv radiation hitting atmospheric oxygen

Question 5

why is the atmosphere system balanced?

Answer 5

• Average energy budget of the earth-atmosphere system
  
  • Why must the earth attempt at maintaining a balance
    That atmospheric layer without balance would cause big shifts in temperature

Question 6

how much of incoming solar energy is scattered?

Answer 6

30% relfected back to space (backscatter)
clouds 16%
air, dust, haze, 6%
earth’s surface 7%

Question 7

how much solar radiation is absorbed by atmosphere

Answer 7

~23% absorbed by atmosphere
absorbed by h2o, dust, o3
absorbed by clouds

Question 8

how much solar energy reaches earth? how much is used in photosynth?

Answer 8

~50%
<1%

Question 9

is earth in a state of radiative balance?

Answer 9

As a global long term average, earth is close to a state of radiative balance

Question 10

how is SR balanced?

Answer 10

amount incoming (shortwave) = amount outgoing (short and long wave)
true for each layer: above atmosphere, atmosphere, earth’s surface

Question 11

what is convection

Answer 11

Convection: heat transfer by turbulent movement of air or water, divided into: Latent heat reflux:
Sensible heat flux:

Question 12

describe latent heat refux

Answer 12

○ Latent heat reflux: energy transferred between a surface and the atmosphere by the evaporation of water or the condensation of water vapor (phase change)

Question 13

describe sensible heat flux

Answer 13

Sensible heat flux: energy conducted from a warm surface to the air immediately above it, and moved upward to the atmopshere (no phase change)

Question 14

NGHE?

Answer 14

• Natural greenhouse effect
  
  • Warming of atmosphere due to atmospheric absorption (by radiatively active gases) of longwave radiation
    Maintains earth at 15 degrees C; without NGHE, earth would be around 33 degrees C cooler

Question 15

Radiatively active gases

Answer 15

• Absorb and reradiate long wave radiation emitted by earth
  
  • H2O, CO2, CH4, N2O, O3, CFCs

Question 16

• • Mean Residence times (mrt)? what is it for n2, o2, and co2

Answer 16

• Total mass divided by the flux into or out of the atmosphere over a given time period
  
  • N2 has a MRT ~13 million years
  • O2 MRT 10,000 years
  • CO2 MRT = ~5 yrs (50% decline in 30 years with ceasing of emissions, 70% decline within a few centuries)

Question 17

Spatial variation in climate is due to?

Answer 17

• Due to:
  ○ Atmospheric system - composition and circulation
  ○ Oceans and ocean circulation
  ○ Landform effects (topography, albedo)

Question 18

look at atmosphere structure diagram

Answer 18

ok

Question 19

describe troposphere

Answer 19

• Troposphere (the weather layer)
  ○ Ends ~10-16 km
  ○ Temp declines with height
  ○ Heated from below; absorbs LW radiation emitted from earth
  Tropopause

Question 20

describe stratosphere

Answer 20

○ Above troposphere (to ~48 km)
○ Temp increases with height
○ Heated from above (SW solar)
○ Uv protector; contains O3 which absorbs UV radiation
* Record is 12km deep
* Bacteria found about 6km deep
* Layers marked by temperature changes
○ Zig zag temp change
* Why are there these changes in atmospheric temp?
Interaction of gases and incoming radiation

Question 21

what is the planetary boundary layer? why is it important? daily rhythm?

Answer 21

• The surface of air that is attached to the planet
  
  • Daily rhythm
    ○ The cloud layer moves up throughout the course of the day -As the day warms up
  • Important in how we interact with the air we breathe
  • Smog, pollution is important in this boundary layer
  • If its low we will be breathing in more

Question 22

what does atmospheric circulation cause

Answer 22

Fundamental cause= uneven heating of the earth surface

Question 23

causes of uneven heating?

Answer 23

• Spherical shape and tilt of earth’s axis
  
  • Sphere
    ○ Equator receives more radiation than poles
    1. Shorter atmospheric path
    2. Concentrated in smaller area
    ○ Greater temperatures at equator
    ○ Drives heat movement (atmospheric circulation) from equator to poles
  • Global seasons
    ○ Spherical shape and tilt of earth’s axis leads to uneven surface heating
    ○ Drives changes in seasons in N and S hemispheres
    ○ Tropics: seasonal variation in temp and day length are slight, but precipitation may vary greatly
    *

Question 24

solar driven air circulation patterns?

Answer 24

• Uneven heating drives air circulation patterns and conequently precipitation patterns
  As the air goes up its less dense

Question 25

how does air circulate?

Answer 25

Sun heats air at equator & warm air rises
Air cools-condenses -rain -tropics
Now dry air moves N/S (cooling &
becoming dense) & sinks at 30degrees lat.
Dry air draws moisture from the land -deserts
Air continuing N & S completes thermal
loop (Hadley cell)

Question 26

3 atmospheric cells?

Answer 26

on either side of equator
polar cell
ferrel cell
hadley cell
look at diagram