bhoo-dhruviya dhaara

bhoo-ushna pravaah ack mahasagariya pravaah haye jisamen dabaav pravanata bull coriolis prabhaav dwara santulit hotaa haye. bhoo-ushna pravaah kii disha samsthaanikon key samanantar haye, jisamen uttari golardh mein pravaah key daaeen or uchch dabaav aur dakshini golardh mein baain or uchch dabaav hotaa haye. yeh avadharana mausam maanchitron seey parichit haye, jinake samasthaanik bhoo-ushna havaaon kii disha dikhaate hain. bhoo-ushna pravaah yaa tou barotropic yaa baroclinic hoe sakata haye. bhoo-ushna pravaah koo shoonya kii aavritti key saath ack ghoornan uthali jall tarang key roop mein bhee socha jaa sakata haye. 
bhoo-patan" yaa "bhoo-ushna santulan" kaa siddhant samudravidon key liye upayogi haye kyonki yeh unhein samudra kii satah kii oonchaai (sanyukt upgrah oonchaai aur gurutvaakarshan dwara) key maap seey yaa jahaajon yaa swaayatt naukaaon dwara liye gaye samudri jall ghanatva key urdhvaadhar profile seey samudra kii dhaaraon kaa anuman lagaane kii anumati detaa haye. duniya key mahasagaron kii pramukh dhaaraaen, jaise kii khaadi dhaara, eurosio dhaara, agulhas dhaara aur antarctic vrittiya dhaara, lagbhag bhoo-aarekh santulan mein hain aur bhoo-aarekh dhaaraon key udaaharan hain.
saral vyakhya.
samudra kaa paani praakritik roop seey uchch dabaav (yaa uchch samudra star) key kshetra seey nimn dabaav (yaa nimn samudra star) key kshetra mein jaataa haye. jall koo nimn daab kshetra kii or dhakelane vaale bull koo dabaav pravanata bull kahaa jaataa haye. bhoo-ushna pravaah mein, uchch dabaav (yaa uchch samudra star) key kshetra seey nimn dabaav (yaa nimn samudra star) key kshetra mein jaane key bajaay, yeh samaan dabaav (isobar) kii rekhaaon key saath chalata haye. aisaa isaliye hotaa haye kyonki prithvi ghoom rahee haye. prithvi key ghoornan key parinamswarup ack "bull" mahsoos kiya jaataa haye joe paani dwara uchch seey nimn kii or badhane parr mahsoos kiya jaataa haye, jise coriolis bull key roop mein jaanaa jaataa haye. coriolis bull pravaah key samkon parr kaary kartaa haye, aur jaba yeh dabaav pravanata bull koo santulit kartaa haye, tou parinami pravaah koo bhoo-aadrvik key roop mein jaanaa jaataa haye. 
jaisa kii oopar kahaa gayaa haye, pravaah kii disha uttari golardh mein pravaah key daaeen or uchch dabaav key saath haye, aur dakshini golardh mein baain or uchch dabaav haye. pravaah kii disha golardh parr nirbhar karati haye, kyonki vibhinn golardhon mein coriolis bull kii disha vipareet hoti haye.
sutrikaran.
bhoo-aarekh sameekaran ack ghoornan sandarbh frame mein naabhik-stokes samikaranon kaa ack saralikrit roop haye. vishesh roop seey, yeh maanaa jaataa haye kii koee twaran (sthir-sthiti) naheen haye, koee chipchipahat naheen haye, aur dabaav hydrostatic haye. parinami santulan haye (gill, 1982): 
jahan sootra _ 3 coriolis parameter haye, sootra _ 4 ghanatva haye, sootra _ 5 dabaav haye aur sootra _ 6 sootra _ 7 dishaaon mein kramshah wegg hain.
bhoo-aarekh samikaranon kaa ack vishesh guna yeh haye kii way nirantarta sameekaran key sthir-avastha sanskaran koo santusht karate hain. vaha haih
shoonya aavritti kii ghoornan tarangen.
ack raikhik, ghoornan uthali jall tarang koo niyantrit karane vaale sameekaran hainh
oopar dee gaee sthir-avastha kii dhaarana (koee twaran naheen) haih
vaikalpik roop seey, humm samay mein ack lahar jaisi, aavadhik, nirbharta maan sakate hainh
iss mamle mein, yadi humm sootra _ 13 nirdhaarit karate hain, tou humm oopar diye gaye bhoo-aarekh samikaranon parr laut gaye hain. iss prakaar ack bhoo-ushna pravaah
ise shoonya kii aavritti key saath ack ghoornan uthale jall tarang key roop mein socha jaa sakata haye.

