Insolation And Energy Flashcards
Why is there weather ?
Weather and climate are a result of temporal and spatial variability in the fluxes of energy to and from the atmospheric system.
Heat from the sun and movement of air - wind.
Name 4 types of energy that are important in the climate system?
Potential
Chemical
Kinetic
Thermal
They all have a role
Where does the earths energy primarily come from?
The sun - radiant energy
What is a prominence ?
Large / Bright / gaseous feature extending outward from suns surface
Hottest area is white
Describe what the sun is
Active ball of gas and plasma
700,000km radius
Temp drops away from core
Rotates -25 days near equator and 36 days near poles
Abundant hydrogen nuclei join together to form helium in centre
Source of electromagnetic radiation
What is the surrounding bit of the sun called ?
The corona
What is the largest part of the sun called?
Convection xome
What zone in the sun is next to the core?
Radiation zone
Define electromagnetic radiation
The waves of the electromagnetic field radiating through space carrying radiant energy
Electric and magnetic fields are perpendicularly one another
How fast does electromagnetic radiation travel ?
Speed of light
300,000 kms-1
What is the wavelength of radiation measured in ?
Micrometers
Millionth of a metre
Um
Give examples of electromagnetic radiation
Microwaves
Infrared
Visible light - UV
X rays
Gamma rays
Define black body
A surface that absorbs all radiant energy falling on it
They radiate energy at a rate directly proportional to the 4th power of their temperature - stefan BM law
Energy is emitted from a black body across range of wavelengths
Give an example of a black body
The sun
What is the suns emissivity ?
1
Define emissivity
The effectiveness of a material in emitting energy as thermal energy - heat
What is the stefan Boltzmann law
E = e o T4
E - energy radiated
e - emissivity 1 for the sun
o - stefan BM constant (5.67x10-8)
T - temperature
Only knowing the temperature of something you can work out how much EM radiation it will emit
What is plancks law
Describes the spectral distribution of emitted energy by a black body
What is weins law
Black body radiation curve for different temps will peak at different wavelengths
Higher temp = shorter the wavelength
What happens to wavelength of black body as the temperature increases
The wavelength decreases - wiens law
What is wiens Constant value
2897.79
What is UV wavelength
<0.4 um
7%
What is visible wavelength
0.4 - 0.7 um
44%
What is near infrared wavelength
0.7 - 1.5 um
37%
WhT is far infrared radiation ?
1.5> um
12%
What is the temp of the sun
~6000 K
5726 degrees C
What is the max wavelength of the sun
0.48 um
Range - 0-4.0 um
What type of radiation does the sun emit
Incoming short radiation
What is the temp of the earth
288 K
15 degrees C
What is the max wavelength of the earth
10.06 um
Range 4- 24 um
What is the emissivity of the earth
~0.64
What radiation does earth emit ?
Outgoing long wave radiation
Define insolation
Exposure to suns rays and the amount of solar radiation reaching a given area
Incoming solar radiation
Name 4 things insolation is determined by
Angel of suns rays
Solar output
Sun earth distance
Day length
How does the angle of the suns rays impact insolation
As area gets larger the light gets dimmer
This is why we have seasons
Summer - more direct over head
Winter - further away at polar regions
Short wave radiation increases with;
•Decreasing latitude.
•Temporal proximity to summer solstice
•solar angle in relation to surface slope
When is the summer solstice
21 june
What is the summer solstice
When the sun travels the longest path through the sky and that day has the most day light
Happens twice yearly - winter shortest day of year
What is the tilt of the earths axis
23.4 degrees
