GEOG NOTES
THE ATMOSPHERE
Suns energy
• Solar energy is generated by the process of nuclear fusion.
• Energy from the Sun travels through space in electromagnetic waves that have both wave and
particle (photon) structures
• Important characteristics of EM waves:
- distance between corresponding points on two successive waves is called the wavelength
- number of waves passing a fixed point per unit of time is the frequency, measured in hertz
(Hz). I Hz is one pulse (wave) per second
- speed at which an electromagnetic wave moves is the speed of light; i.e. 3 x 108 m.s-1, or 30 000
km.s-1
- c = λν - short wavelength = higher frequency
• Temp= average measure of a kinetic energy per molecule of an object
• Heat=The total (sum) kinetic energy of all molecules in an object
• Absolut 0= when molecules have no energy. The total (sum) kinetic energy of all molecules in an
object
• Sensible heat= Heat acquired by an object, through transfer from another object of higher
temperature
• Latent heat= Heat acquired or lost when a body changes to a different physical state
• Climate- persistent weather patterns that are derived from a statistical analysis of at least
30 years of data
•
,x
,EARTH AND SUN RELATIONSHIP
• Plane of the ecliptic- plane that depicts the Earth’s orbit about the Sun
• Perihelion-reached just after the December Solstice, when the Earth is closest to the sun,
147 255 000 km away, on January 3
• Aphelion- reached on July 4, just after the June Solstice, when the Earth is 152 083 000 km away
from the sun
• Austral- has to do with the southern hemisphere
• Boreal- has to do with the northern hemisphere
Furthest closest
• Tilt of earth and earths path cause seasons
• Position of the sun is only one of the factors that controls the amount of energy that reaches the
Earth’s surface, and hence the temperature of the surface
, • Earth only receives one two-billionth of the Sun’s total energy output
• Tropics receive 2½ times more energy than the poles as the insolation is concentrated due to
Earth’s curvature- rays more likely to hit surface at 90 degrees
• Polar gets oblique rays therefore its colder
• Earth receives shortwave radiation from the sun- Gamma rays, X-rays, and UV(8%); Visible
light (47%); and Infrared (45%), (the radiation that warms us)-a large portion of which is
stored in the ground and re-radiated as longwave radiation= low budget at poles, high by
tropics
Diurnal Cycle of Electromagnetic Radiation
• The day/night
1. sunrise, the earth begins intercepting mainly short wavelength energy (0.4 - 0.7 µm) from
the sun
2. Some of the incident short-wavelength energy is absorbed by the Earth
3. re-radiated back into the atmosphere as thermal Infra-Red (IR) long-wavelength radiation
4. Outgoing longwave radiation reaches its highest value during the day when the surface
temperature is highest (highest longwave radiation when surface temp is highest)
• Reflected short-wavelength energy and emitted long-wavelength energy causes an energy
surplus during the day.
• Both incoming and outgoing shortwave radiation become zero after sunset
• Outgoing longwave radiation continues all night
• The Earth is not a perfect Blackbody (one that absorbs all radiation), or Whitebody (one that
reflects all radiation)
• Dangerous, high-energy gamma and x-rays are blocked
THE ATMOSPHERE
Suns energy
• Solar energy is generated by the process of nuclear fusion.
• Energy from the Sun travels through space in electromagnetic waves that have both wave and
particle (photon) structures
• Important characteristics of EM waves:
- distance between corresponding points on two successive waves is called the wavelength
- number of waves passing a fixed point per unit of time is the frequency, measured in hertz
(Hz). I Hz is one pulse (wave) per second
- speed at which an electromagnetic wave moves is the speed of light; i.e. 3 x 108 m.s-1, or 30 000
km.s-1
- c = λν - short wavelength = higher frequency
• Temp= average measure of a kinetic energy per molecule of an object
• Heat=The total (sum) kinetic energy of all molecules in an object
• Absolut 0= when molecules have no energy. The total (sum) kinetic energy of all molecules in an
object
• Sensible heat= Heat acquired by an object, through transfer from another object of higher
temperature
• Latent heat= Heat acquired or lost when a body changes to a different physical state
• Climate- persistent weather patterns that are derived from a statistical analysis of at least
30 years of data
•
,x
,EARTH AND SUN RELATIONSHIP
• Plane of the ecliptic- plane that depicts the Earth’s orbit about the Sun
• Perihelion-reached just after the December Solstice, when the Earth is closest to the sun,
147 255 000 km away, on January 3
• Aphelion- reached on July 4, just after the June Solstice, when the Earth is 152 083 000 km away
from the sun
• Austral- has to do with the southern hemisphere
• Boreal- has to do with the northern hemisphere
Furthest closest
• Tilt of earth and earths path cause seasons
• Position of the sun is only one of the factors that controls the amount of energy that reaches the
Earth’s surface, and hence the temperature of the surface
, • Earth only receives one two-billionth of the Sun’s total energy output
• Tropics receive 2½ times more energy than the poles as the insolation is concentrated due to
Earth’s curvature- rays more likely to hit surface at 90 degrees
• Polar gets oblique rays therefore its colder
• Earth receives shortwave radiation from the sun- Gamma rays, X-rays, and UV(8%); Visible
light (47%); and Infrared (45%), (the radiation that warms us)-a large portion of which is
stored in the ground and re-radiated as longwave radiation= low budget at poles, high by
tropics
Diurnal Cycle of Electromagnetic Radiation
• The day/night
1. sunrise, the earth begins intercepting mainly short wavelength energy (0.4 - 0.7 µm) from
the sun
2. Some of the incident short-wavelength energy is absorbed by the Earth
3. re-radiated back into the atmosphere as thermal Infra-Red (IR) long-wavelength radiation
4. Outgoing longwave radiation reaches its highest value during the day when the surface
temperature is highest (highest longwave radiation when surface temp is highest)
• Reflected short-wavelength energy and emitted long-wavelength energy causes an energy
surplus during the day.
• Both incoming and outgoing shortwave radiation become zero after sunset
• Outgoing longwave radiation continues all night
• The Earth is not a perfect Blackbody (one that absorbs all radiation), or Whitebody (one that
reflects all radiation)
• Dangerous, high-energy gamma and x-rays are blocked
