The Sun and Seasons Flashcards
According to the planetesimal hypothesis, the solar system formed from a large…
Slowly rotating “nebula”
When/what is it called when the Earth closest to the sun?
Perihelion, Jan. 3
When/what is called when the Earth is farthest from the sun?
Aphelion, July 4
How much matter does the sun contain from the original nebula?
99.9%
Solar mass is converted to…
Energy by fusion of hydrogen atoms
What does the sun emit?
Charged particles called SOLAR WIND
Seasonality
Refers to the variation in the sun’s altitude and the changing length of daylight that occurs over the year
As the Earth rotates on its axis, in the same direction, what does it produce?
- Diurnal rhythms
- Coriolis effect
- Even distribution of radiant energy along parallels
What is the Earths tilt?
23.5 degrees with respect to the ecliptic
What is the latitude of the sub-solar point (AKA solar declination)?
231⁄2° N and 231⁄2° S during the year
Why do you get a sunburn in summer, but not winter? Or in the tropics, but not in Vancouver?
The angle of incidence (of incoming radiation) and the strength of the solar beam affect the amount of heating
When is winter solstice?
December 21-22 @ 23.5°S
When is summer solstice?
June 20-21 @ 23.5°N
When is vernal equinox?
March 20-21 @ the equator
When is autumnal equinox?
September 22-23 @ equator
