ENVIRSC 1C03 Lecture Notes - Lecture 5: Ecliptic, Heat Flux, Radiant Intensity

• School: McMaster University
• Department: Environmental Science
• Course: ENVIRSC 1C03
• Professor: Luc Bernier

Document Summary

Earth closest to the sun in january at 147 mil km; perihelion. Farthest point = july 4th at 152 mil km; aphelion. This results in a variation in radiation intensity of ~7% b/w perihelion and aphelion. Earth spins on its axis as it revolves around sun; completed every 24 hrs. Axis tilted by (cid:1006)(cid:1007). (cid:1009) f(cid:396)o(cid:373) the e(cid:272)lipti(cid:272) pla(cid:374)e. Northern axis aligns w/ the star polaris. Daily variation in air temp is controlled by the net radiation; the balance b/w incoming and outgoing solar and infrared radiation. When outgoing > incoming, net radiation = -ve: air temp falls, temp coolest at sunrise. June solstice is around june 21 and marks the beginning of summer in northern hemi, and winter in southern. Longest day of the yr in north, shortest in south. December 22; beginning of winter in north, summer in south. Shortest day in north, longest day in south.