review question in your own words, define geography. bad answer: the science that studies the...
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Review QuestionIn your own words, define Geography.
BAD Answer:The science that studies the relationships between natural and cultural systems and the interdependence of the two over space and time
These are not YOUR words!
Review QuestionSunspots
A) Are produced by coronal mass ejections
B) Are caused by solar wind
C) Have activity cycles
D) Are clouds of electrically charged particles
Review QuestionAccording to Wein’s Law
A) The electromagnetic spectrum divides radiant energy
B) Longer wavelengths have higher energy
C) Shorter wavelengths have high energy
D) The Earth is an open system in terms of energy
Review QuestionSolar rays pass through more atmosphere before reaching the poles, so more energy is lost to ____________, ______________, and _______________.
Absorption, scattering, and reflection
Chapter 2Solar Energy to Earth and
the Seasons
Geosystems 6eAn Introduction to Physical Geography
Robert W. ChristophersonCharles E. Thomsen
Perihelion and Aphelion
The Seasons Seasonality: the variation of the sun’s position over the horizon; the changing daylength during the year Seasons result from:
variations in the sun’s altitude – angle between the horizon and the sunthe suns’s declination – latitude of the subsolar pointand daylength - duration of exposure to insolation
Reasons for Seasons Revolution
Rotation
Tilt of Earth’s axis
Axial parallelism
Sphericity
Reasons for Seasons Revolution
Earth revolves around the Sun
Voyage takes one year
Earth’s speed is 107,280 kmph (66,660 mph)
RotationEarth rotates on its axis once every 24 hours
Rotational velocity at equator is 1674 kmph (1041 mph)
Revolution and Rotation
Figure 2.13
Reasons for Seasons Tilt of Earth’s axis
Axis is tilted 23.5° from plane of ecliptic
Axial parallelismAxis maintains alignment during orbit around the Sun
North pole points toward the North Star (Polaris)
Sphericity
Axial Tilt and Parallelism
Figure 2.14
Seasonal Observations
Figure 2.17
Seasonal Observations
SUMMER HEMISPHERE
Carrollton = 33°N
What is Sun’s angle (at noon)
on June 21?
90 – |(latitude – subsolar point)|
90 – |(33 – 23.5)| = 80.5 °
WINTER HEMISPHERE
90 – (latitude + subsolar point)
What is the Suns’ angle (at noon)
on Dec 21?
90 – (33 + 23.5) = 33.5 °
Seasonal ObservationsWhat is the noon altitude of the sun at Carrollton at the equinoxes?
Use either summer or winter hemisphere equation
90 – |(latitude – subsolar point)|
90 – |(33 – 0)| = 57°
Annual March of the SeasonsWinter solstice – December 21 or 22
Subsolar point Tropic of Capricorn
Spring equinox – March 20 or 21Subsolar point Equator
Summer solstice – June 20 or 21Subsolar point Tropic of Cancer
Fall equinox – September 22 or 23Subsolar point Equator
Annual March of the Seasons
Figure 2.15
End of Chapter 2
Geosystems 6eAn Introduction to Physical Geography
Robert W. ChristophersonCharles E. Thomsen