MONSOONS Bi Lateral seasons Wet and Dry 30 degrees north and south of the equator are considered tropical this is where monsoons are most prevalent 65 degrees north and south of equator Have temperate season spring summer fall winter 90 degrees north and south of equator Have polar season warm and cold Equator has most incoming solar radiation Rotates from 0 30 degrees north and south of equator because of axis of An equinox is when either hemisphere not tilted toward or away from the sun earth It also is because its orbit Fall and Spring 12 hours and night Northern Hemisphere summer THERMAL equator moves toward north SOLSTICE June 21st 18 hours of day and 6 hours of night That is considered the winter solstice in the southern hemisphere From North Pole on Summer Solstice the sun never dips the horizon Winter Solstice December 21st Tilted away and less time of day Shortest day of the year in North Wind Air circulation caused by temperature If the earth didn t rotate on axis We d get two convection shells Flow in air mass to temperate gradients Hot temps result in less dense air mass Vertically rise in atmosphere MOIST Cold temperature more dense air mass Sink down in atmosphere DRY The CORIOLIS effect Earth s rotation causes deflection of prevailing winds Sense of deflection depends upon Initial direction of motion Positive relative to equator Coriolis deflection can be modeled on a merry go round EQUATOR spins FAST than POLES InterTropic Convergent Zones Go with tilt of the earth MONSOON Floods Asia Droughts Africa