GEOG 155 Chapter Notes - Chapter 4: Antarctic Circle, September Equinox, Solar Irradiance
Document Summary
Plane of the ecliptic: the geometric plane in which earth"s orbit around the sun lies. Seasons occur because of the tilt of the earth. Solstices and equinoxes: solstices: days of poleward extremes in the latitude. Summer solstice: each year, day of the poleward extreme in the latitude where the sun"s noontime rays strike the earth"s surface vertically (june. The four seasons: the passage of seasons has been a basis for establishing secure reference points for measuring time. Circle of illumination: the boundary between the lit half of the earth and the dark half of the earth. Solar position and its effects: not all places receive equal solar radiation inputs. Locations having a nearly vertical sun at noon receive more radiation than places where the sun is low in the sky at noon. Zenith: point in sky directly overhead, 90 degrees above the horizon. Solar altitude: the angel of the sun above the horizon.
