Why are many of Earth's large deserts located near 30 degrees north and 30 degrees south latitude?


(global) ocean covers earth's 71% surface. ocean area's humongous water mass absorbs enormous quantity of solar energy (water has highest specific heat amongst liquids, implying takes lot of energy heat unlike metal gets heated less heat energy). sets temperature differential between surfaces of land & sea. hotter (warmer) area sends air cooler area in vicinity. call moving air 'breeze'. whenever such breeze comes sea onto land (if sea warmer), brings moisture condenses & precipitates rain. simple picture without further nuances.
ocean has processes. west east movement of earth & coriolis effect set currents in ocean identically patterned between same latitudes & confined land in east & west. these clockwise (cw) in northern hemisphere & counter clockwise (ccw) in southern hemisphere. cold current sinks bottom while warm current on surface. cold polar current pole equator gets warmed enough come surface (up-welling) in mid-latitudes, continental land east. yet colder land (shore). warmer land sends breeze onto sea, shunning sea breeze onto land. deprives moisture on land desiccated. hence such areas (western shores of continents @ 30ยบ) dry. climate extends interior (landwards) till other climatic zone meets it. reason why great sahara (spread on 3 million miles²) continues cluster of arabian deserts, iranian deserts, thar desert in india, in central eurasia till gobi north of china.
in summer blazing hot sun (about) directly @ zenith. in winter while adjacent area in mediterranean climate (pole-wards), gets rains (for same reason), sea breeze brings moisture in night (as sea water isn't cooled down as land cools fast) 'dew' in thin strip of coast.
pattern deprives rivers being formed there, except coming form other rain-fed or snow-fed areas depending on topography & orography ('lie' of mountain ranges). nile, sindhu (indus) & hwang-he such rivers.



Science & Mathematics Geography Next



Comments

Post a Comment

Popular posts from this blog

Reflections on a dream, would you kindly c/c?

snow in march in sleep found childhood friend @ play in northridge park. cheeks stained fallen tears, bobbed hair sleek , dark. snow slow melt march, our breath condensed in air , recall clarity while on lower stair, neighbour called pass on news, jeannie's mum dead. overheard whispered tones, should have been in bed. oh jeannie after time, face still wet grief. have pleased me more if had found relief. if had captured in eyes laughter once shared, wouldn't feel life had been impaired. snow in march in sleep found childhood friend @ play in northridge park. cheeks stained fallen tears, bobbed hair sleek , dark. snow slow melt march, our breath condensed in air , recall clarity while on lower stair, neighbour called pass on... Arts & Humanities Poetry Next
Read more

How did they get the Skytrain to go underneath False Creek?

canadians have been blasting through mountains , going on or under waterways centuries - george massey tunnel under fraser river being local example. [during ww2 there sorts of tunnels built going under downtown connecting factories waterfront] believe construction on dunsmuir tunnel ("skytrain tunnel") began in 1931? http://www.vancouverhistory.ca/archives_... dunsmuir tunnel http://en.wikipedia.org/wiki/dunsmuir_tu... the new skytrain line goes yaletown, under false creek , airport, how have been built underneath false creek? Travel Canada Vancouver Next
Read more

Where would "rattlesnake country" be?

rattlesnakes group of venomous snakes of genera crotalus , sistrurus[1] of subfamily crotalinae ("pit vipers"). there 32 known species of rattlesnake, between 65-70 subspecies,[2] native americas, ranging southern alberta , southern british columbia in canada central argentina. http://en.wikipedia.org/wiki/rattlesnake fyi, when rattlesnake bites human injects poison 1 time in ten. according park rangers, on 90% of reported bites happen while tourists harassing snake. i hear people use phrase "this rattlesnake country". i'm not sure is. reason thought ozark mountains, saw on tv , in hollywood hill. know? Science & Mathematics Geography Next
Read more