0
17.5 Atmospheric Structure
►Troposphere – the layer we live in
 Most weather
 All clouds & water vapor
 Cools as you go...
17.5 Atmospheric Structure
►Stratosphere – temp constant to 35km
 Increases up to 50km
 Ozone forms here
 Above 55km (s...
Fig. 17.10, p.440
18.1 Incoming solar radiation
►Light – behaves like a wave and a particle
 Photons – elementary particles of light
 Elec...
18.1 Incoming solar radiation
►Absorption – when something absorbs
radiation, the photon’s energy can initiate
chemical an...
18.1 Incoming solar radiation
►Reflection –electromagnetic radiation
bouncing from a surface
 Albedo – proportional refle...
Fig. 18.4, p.454
Fig. 18.5, p.455
► Scattering – gases and water droplets scatter light
in all directions
 short “blue” wavelengths scatte...
18.2 the radiation balance
►Earth’s surface absorbs light energy
 Most is re-emitted, mainly as heat
 Greenhouse effect ...
Fig. 18.6, p.455
18.3 Energy storage & transfer
– climate’s driving mechanism
►Temperature – is proportional to the
average speed of atoms ...
18.3 Energy storage & transfer
– climate’s driving mechanism
►Conduction – transfer of heat by direct
collisions of molecu...
Fig. 18.8a, p.457
Convection example: heat from a stove heating a room
Fig. 18.8b, p.457
Convection within the atmosphere
p.459
Recall that the
Earth is curved
And lines of Latitude
Are horizontal to the
Equator and increase in
Degrees from 0 t...
18.4 temperature changes
with latitude & season
►Temperature decreases as latitude increases
 Light strikes more directly...
Fig. 18.11, p.460
Fig. 18.10, p.460
18.4 temperature changes
with latitude & season
►The seasons – related to orbital parameters
 Earth’s axis is tilted. Dur...
Fig. 18.12, p.461
18.5 Temperature changes
with geography
►Altitude – temperature decreases with
altitude
►Ocean effects – land heats more q...
18.5 Temperature changes
with geography
►Cloud cover and albedo
 Clouds intercept light energy
►They cool during day by b...
Fig. 18.18, p.466
Upcoming SlideShare
Loading in...5
×

HPU NCS2200 Chapter17& 18 primary atmosphere structure and function

71

Published on

HPU NCS2200 earth science for elementary education majors summer 2014 online class atmosphere structure and function lecture 1

Published in: Education, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
71
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
6
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "HPU NCS2200 Chapter17& 18 primary atmosphere structure and function"

  1. 1. 17.5 Atmospheric Structure ►Troposphere – the layer we live in  Most weather  All clouds & water vapor  Cools as you go up ►Tropopause – ~17km high, the cooling ends abruptly, little mixing with troposphere
  2. 2. 17.5 Atmospheric Structure ►Stratosphere – temp constant to 35km  Increases up to 50km  Ozone forms here  Above 55km (stratopause) temps fall again ►Mesosphere – thin air, very cold up to 80km ►Thermosphere – above 80km, temps rise rapidly (to just below freezing!)  Hi-energy environment
  3. 3. Fig. 17.10, p.440
  4. 4. 18.1 Incoming solar radiation ►Light – behaves like a wave and a particle  Photons – elementary particles of light  Electromagnetic radiation – light also behave as energy waves, perpendicular electrical and magnetic waves ►Wavelength – distance between wave crests ►Frequency – number of waves passing a point/sec. ►Electromagnetic spectrum – continuum of electromagnetic wavelengths
  5. 5. 18.1 Incoming solar radiation ►Absorption – when something absorbs radiation, the photon’s energy can initiate chemical and/or physical reactions  Excited state – absorbed photons makes electrons get “excited”  Emission of radiation – when the exited electrons “settle down” they emit light ►All objects emit some radiation ►Emission color (wavelength) relates to temperature
  6. 6. 18.1 Incoming solar radiation ►Reflection –electromagnetic radiation bouncing from a surface  Albedo – proportional reflectance of a surface ►(e.g.: a perfect mirror would have an albedo of 100%) ►Glaciers & snowfields approach 80-90% ►Clouds – 50-55% ►Pavement and some buildings – only 10-15%
  7. 7. Fig. 18.4, p.454
  8. 8. Fig. 18.5, p.455 ► Scattering – gases and water droplets scatter light in all directions  short “blue” wavelengths scatter more, so skies are blue
  9. 9. 18.2 the radiation balance ►Earth’s surface absorbs light energy  Most is re-emitted, mainly as heat  Greenhouse effect – some gases and water vapor absorb some of this heat ►Dust, clouds, aerosols, particulates all affect atmospheric temperature  Hi-altitude dust can reflect light  Lo altitude particles can absorb heat
  10. 10. Fig. 18.6, p.455
  11. 11. 18.3 Energy storage & transfer – climate’s driving mechanism ►Temperature – is proportional to the average speed of atoms or molecules in a sample.  E.g.: hot water molecules move faster than cold water molecules ►Heat – is a measure of the total energy in a sample  average energy X number of molecules  E.g.: bathtub of ice has more heat than a cup of tea
  12. 12. 18.3 Energy storage & transfer – climate’s driving mechanism ►Conduction – transfer of heat by direct collisions of molecules  Heat, good conductor; air, poor conductor ►Convection – transfer of heat by the motion of a fluid medium ►Advection - horizontal air flow (meteorological term)
  13. 13. Fig. 18.8a, p.457 Convection example: heat from a stove heating a room
  14. 14. Fig. 18.8b, p.457 Convection within the atmosphere
  15. 15. p.459 Recall that the Earth is curved And lines of Latitude Are horizontal to the Equator and increase in Degrees from 0 to 90
  16. 16. 18.4 temperature changes with latitude & season ►Temperature decreases as latitude increases  Light strikes more directly at low latitudes ►more energy per unit area, heats more effectively  At high latitudes, the sun strikes quite obliquely ►At some point during the year at poles, it doesn’t strike at all
  17. 17. Fig. 18.11, p.460
  18. 18. Fig. 18.10, p.460
  19. 19. 18.4 temperature changes with latitude & season ►The seasons – related to orbital parameters  Earth’s axis is tilted. During northern summer, the light hits more directly and in winter less so  Tropics – the latitudes of 23.5o N/S are where light his directly on summer and winter solstice  Equinox, when an area gets 12 hours each of light and dark ►On average, all areas of the globe receive the same sunlight time annually
  20. 20. Fig. 18.12, p.461
  21. 21. 18.5 Temperature changes with geography ►Altitude – temperature decreases with altitude ►Ocean effects – land heats more quickly than water, so inlands see greater temperature extremes  Currents often transfer heat to moderate temperatures (e.g.: the Gulf Stream)
  22. 22. 18.5 Temperature changes with geography ►Cloud cover and albedo  Clouds intercept light energy ►They cool during day by blocking the sun  Clouds have high albedo, turning incoming energy back towards space ►Then warm at night by trapping ground-emitted heat  Clouds have high albedo, turning outgoing energy back to ground ►Snow effects solar input in similar fashion, it is reflective while soil/rock is not
  23. 23. Fig. 18.18, p.466
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×