ENVIRSC 1C03 Lecture Notes - Lecture 5: Ecliptic, Subsolar Point, June Solstice
Document Summary
Total rotation of earth around the sun is 365 days (1 year); known as the earth"s revolution. Earth travels around the sun in an ecliptic plane (flat plane, plane goes through the sun laterally) Earth is closest to the sun in january (point known as perihelion) Earth is farthest from the sun around july 4th (point known as aphelion) The change in distance results in a variation in radiation intensity of 7% between the 2 points. The earth rotates the sun in an ecliptic plane. The earth also spins on its axis as it revolves around the sun (completes 1 spin every 24 hours); this rotation defines the length of 1 day; spins from west to east. The earth"s axis of rotation is not perpendicular to its orbital/ecliptic plane. It is tilted by 23. 5 from the ecliptic plane and the northern axis (of the ecliptic plane) aligns with the star.