Climatology Lecture 1 - PowerPoint PPT Presentation

Loading...

PPT – Climatology Lecture 1 PowerPoint presentation | free to view - id: 15ce0e-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Climatology Lecture 1

Description:

Attenuation of radiation (absorption, scattering, reflection): what the ... Krakatoa explosion 1883 10-5. nuclear bomb 10-5. summer thunderstorm 10-8. tornado 10-11 ... – PowerPoint PPT presentation

Number of Views:165
Avg rating:3.0/5.0
Slides: 40
Provided by: RichardWa1
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Climatology Lecture 1


1
Climatology Lecture 1
  • Michael Palmer
  • Lectures available on
  • www.atm.ox.ac.uk/user/mpalmer/

2
Michael Palmer
  • Geography _at_ CATZ……finished 1997.
  • Gap year 1998 Work Travel.
  • PhD 1998 . Natural Variability of the (Lincoln)
    Climate System.

Department of Atmospheric Physics Room
119 mpalmer_at_atm.ox.ac.uk
3
Climatology
  • 12 Lecture Course
  • Michaelmas Term 2001 (Weeks 1-4)
  • 2 tutorials in College (typically 2 essays)

Lectures available on www.atm.ox.ac.uk/user/mpal
mer/
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
What causes weather and climate?
  • Heating
  • Rotation

9
Course Outline
  • Heat and the Earths Atmosphere
  • Vertical Motion Stability
  • Horizontal Motion Winds
  • The General Circulation Midlatitudes
  • The General Circulation Tropics
  • Variability of the General Circulation

10
Heat and the Earths Atmosphere
  • The basics of the atmosphere vertical structure
    and composition
  • Heat transfer through radiation

11
Heat and the Earths Atmosphere
  • The basic structure of the atmosphere
  • Heat transfer through radiation Electromagnetic
    spectrum Black body radiation Planck's law,
    Stefan-Boltzmann law, Wien's law
  • Attenuation of radiation (absorption, scattering,
    reflection) what the atmosphere does with the
    suns heat
  • The effective temperature of the earth life
    without greenhouse?
  • Terrestrial radiation and the Greenhouse effect
  • the radiation budget
  • variation of the terms of the radiation budget
    diurnal, seasonal, spatial

12
(No Transcript)
13
Atmospheric Composition
  • Mechanical Mixture of Gases Gas Volume (dry
    air)
  • Nitrogen 78.1
  • Oxygen 20.9
  • Argon 0.9
  • Also important trace gases
  • CO2 370ppmv (1999)
  • Water Vapour
  • Ozone

14
Heat and the Earths Atmosphere
  • Heat can be transferred in 3 Ways Radiation Co
    nvection Conduction

15
Heat and the Earths Atmosphere Radiation
  • Nearly all the Earths energy comes from the Sun
  • Sun nuclear reactor
  • Earth receives less than one billionth of the
    Suns energy
  • If the Earth could be viewed from the Sun, it
    would appear as a speck in the solar system, with
    the equivalent diameter of a 5p coin observed
    from a distance of 265m

16
Radiation Total energy of phenomena relative to
total solar energy per day
  • Solar energy received per day 1
  • Strong earthquake 10-2
  • Average Hurricane 10-4
  • Krakatoa explosion 1883 10-5
  • nuclear bomb 10-5
  • summer thunderstorm 10-8
  • tornado 10-11

17
Heat and the Earths Atmosphere Radiation
  • Electromagnetic Spectrum All the wavelengths of
    radiant energy which can travel through the
    vacuum of space at the speed of light......
  • (Only means for the planet to transfer energy to
    space)
  • Characterised by wavelengths

18
Wavelength
Low Frequency Long Wave
Amplitude
High Frequency Short Wave
19
Wavelength
10 000 km
Long Radio Waves
1 000 km
100 km
10 km
1 km
AM Radio Waves
100 m
10 m
Short Radio Waves
TV
FM
1 m
Weather
100 mm
10 mm
Microwaves
Radar
1 mm
Infrared
Visible Light
Ultraviolet
X Rays etc
20
Important Wavelengths for Climate
  • Short wave radiation from the Sun 0.48 microns
  • Long Wave Radiation from the Earth/Atmosphere 10
    microns measurements in microns 1 micron 10-6
    m 1/1000mm

21
Why does radiation have characteristically
different wavelengths?
22
Why does radiation have characteristically
different wavelengths? Radiation Laws
23
  • All bodies with a temperature gt 0 K emit
    radiation
  • Wavelength characteristics determined by
    Radiation Laws Plancks Law Wiens
    Law Stefan-Boltzmann Law

24
Plancks Law
  • gives Radiation emitted by a body as a function
    of wavelength and temperature

25
Plancks Curve SUN
10
107 Wm-2 µm-1
0
0.5
1.0
1.5
3.0
2.0
2.5
Wavelength (microns)
26
Wiens Law
  • Wavelength at which maximum emission of radiation
    occurs
  • wavelength of maximum emission is inversely
    proportional to temperature
  • hotter bodies emit shorter wavelengths
  • cooler bodies emit longer wavelengths

27
Plancks Curve SUN
10
Peak Emission
107 Wm-2 µm-1
0
0.5
1.0
1.5
3.0
2.0
2.5
Wavelength (microns)
28
Wiens Displacement Law
  • Sun 2897/T 2897/6000 0.5
    microns Earth 2897/288 10 microns

29
Plancks Curve SUN
107 Wm-2 µm-1
Wavelength (microns)
30
Stefan-Boltzmann Law
  • The energy emitted by a body is directly
    proportional to the fourth power of the
    temperature of that body
  • hot bodies emit a lot more radiation than cooler
    bodies
  • emission 5.67x10-8 T4

31
Plancks Curve SUN
10
107 Wm-2 µm-1
0
0.5
1.0
1.5
3.0
2.0
2.5
Wavelength (microns)
32
Radiation Laws
  • Apply to Black Bodies
  • Theoretical bodies capable of absorbing all
    radiation incident upon them and re-emitting
    maximum possible radiation in all wavelengths and
    all directions
  • Earth and the atmosphere do not behave as black
    bodies
  • Emissivity ratio of emission of natural body to
    theoretical black body

33
6000K
short wave
visible
99.99 energy
34
6000K
short wave
visible
99.99 energy
288 K long wave infrared
35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
Readings for todays Lecture
  • Barry, R.G. and Chorley, R.J. 1998 Atmosphere,
    Weather and Climate (7th Ed.) Chapter 2 (H679)
  • Eagleman, J.R. 1980 Meteorology, the atmosphere
    in action Chapter 3.
  • Henderson-Sellers, A. and Robinson, P.J. 1999
    Contemporary Climatology. Harlow Chapter 2 (H693)
  • Lockwood, J.G. 1974 World Climatology. An
    Environmental Approach. London Edward Arnold,
    330pp. page 6-14.
  • McIlven, J.F.R. 1992 Fundamental of Weather and
    Climate. Wokingham Van Norstrand Reinhold,
    457pp. Chapter 8.
  • OHare, G. and Sweeney, J.1987 The atmospheric
    system (SoG H450)
  • Briggs, D. et al 1997. Fundamentals of Physical
    Environment, Chapters 2-4.
About PowerShow.com