Geosystems Chapter 2
During the Winter Solstice how many hours of daylight is received by 30°N and 30°S?
10h 4m (N) and 13h 56m (S).
During the summer solstice, how many hours of daylight is received by 30°N and 30°S?
13h 56m (N) and 10h 4m (S).
Heat Budget
0° latitude (equator) has a surplus of heat while the poles have a deficit of heat.
What is the sun's energy generated by?
Fusion reaction and convective currents.
Electromagnetic Radiation (EM)
Generated by the sun.
Aurora Borealis
Northern lights
Convection
Occurs within the sun and causes it to constantly disperse energy.
Aurora Australis
Southern Lights
Earth's rotation axis is inclined to what degree?
23.5°
What is the degree of the Tropic of Cancer?
23.5° N
What is the degree of the Tropic of Capricorn?
23.5°S
How much direct/indirect radiation is absorbed into earth's surface?
51%, so about half.
What is the degree of the Arctic Circle?
66.5°N
What is the degree of the Antarctic Circle?
66.5°S
What is the degree of the polar zones?
90°
About how hot is the sun?
About 12,000°F
Plane of the Ecliptic
An imaginary plane (flat surface) intersecting all the points of Earth's orbit around the sun.
Equinoxes
Consists of fall and spring; "equal"; everywhere in the world during this time receives 12 hours of day and night.
Solstices
Consists of summer and winter; during either solstices at one point the north or south pole has 24 hours of darkness.
Winter Solstice
December 21; Direct rays are at the Tropic of Carpricorn; The North Pole (Arctic Circle) receives 24 hours of darkness while the South Pole (Anarctic Circle) receives 24 hours of daylight.
When is the best time to go backpacking in Santiago, Chile (33° 27' 0" S, 70° 40' 0" W)?
During our winter, December so that there will be more daylight.
On which two days during the year does everywhere on Earth experience 12 hours of daylight and 12 hours of darkness?
During the Equinoxes so September 22 and March 21.
Parallelism
Earth's axis stays parallel to its previous positions; the axis is always pointing in the same direction, it never switches sides or anything.
What are the 5 reasons for seasons?
Earth's evolution, rotation, tilt, parallelism, and sphericity.
Tropic Zone Characteristics
Equal duration and direct radiation; HIGH average insolation.
During the equinoxes the sun is directly over what?
Equator
Polar Zone Characteristics
Extreme High/Low duration, indirect radiation; LOW average insolation.
What is the duration of radiation?
How long the sun is above the horizon; day length.
What is the acronym for Incoming Solar Radiation?
Insolation
What is the movement of the earth?
It rotates around its axis (24 hours) and revolves around the sun (365 days/a year).
Summer Solstice
June 21; Direct rays are at the Tropic of Cancer; The South Pole (Anarctic Circle) receives 24 hours of darkness while the North Pole (Arctic Circle) receives 24 hours of daylight.
Declination
Latitude at which the noon sun is directly overhead.
What kind of radiation does the earth release and why?
Longwave radiation; it is a cooler object.
Vernal Equinox (Spring)
March 21
What is the earth's shape?
Oblate Spheroid
Thermonuclear Fusion
Powers the sun and creates energy; When 2 hydrogen atoms fuse together to form 1 helium atom.
Sun's Oblique Rays
Rays hit more areas/cover more space at about a 26° angle.
Sun's Vertical Rays
Rays hit more directly on the earth in an area at about a 73°.
Mid-Latitude Zone Characteristics
Seasonal duration and directness; MEDIUM average insolation.
Autumnal Equinox (Fall)
September 22
Which wavelength has more energy?
Shorter wavelength
What kind of radiation does the sun release and why?
Shortwave radiation; it is a hotter object so it has more energy.
What is the name of the declination chart?
The analemma
Why does the analemma chart only go from 24°N to 24° S?
Those are the only areas that experience declination from the sun.
During the June Solstice the sun is directly over what?
Tropic of Cancer
Where is the declination of the sun on June 21? December 21?
Tropic of Cancer (23.5°N); Tropic of Capricorn (23.5°S)
During the December Solstice the sun is directly over what?
Tropic of Capricorn
Which zone receives the most energy?
Tropical zone
What are the latitudinal zone variations?
Tropical zones, polar zones, and middle latitude zones.
Perihelion
When the earth is its closest to the sun; January 3rd.
Aphelion
When the earth is its furthest to the sun; July 4th.
When are auroras created?
When the magnetic field reacts with sun's energy.
Radiation: Scattered
When the sun's radiation hits a particle and bounces off anywhere (so it can be absorbed, reflected back to the atmosphere, wherever).
Radiation: Absorbed
When the sun's radiation is absorbed into the earth.
Radiation: Reflected
When the sun's radiation reflects off an object and is sent back into the atmosphere.
What would happen if Earth stopped rotating on its axis?
Year length would stay the same, a day would last as long as a year, and loss of centrifugal force causing the ocean to migrate towards the poles.