GEOG 3 Lecture Notes - Lecture 2: Solar Irradiance
Document Summary
Lecture 2: solar energy to earth and seasons. The sun supplies 99% of the energy in the earth system. Energy from the sun is transferred through space and the atm. to the surface of the. Since this energy warms that surface & atm. , some of it becomes thermal (heat) energy. Earth"s orbit around the sun is elliptical, moving in the plane of the ecliptic: elliptical: a closed oval (nearly circular) path, 1 revolution ever 365. 25 days. Average earth-sun distance = 150 million km. It takes sunlight approximately 8 minutes to travel from the sun to earth: aphelion - july 4th. Earth"s farthest from the sun, e-s stance = 152 million km: perihelion - jan 3rd. Earth closest to the sun, e-s distance = 147 million km. The sun emits energy in the form of electromagnetic waves or radiation that travel through space. A tiny fraction of this energy is intercepted by the earth.
