Umkhuba we "Umfana nentombazane" Ziyi-cyclical futhi zisebenza ngokuvumelana nezimo zezulu. I-World Meteorological Organization (WMO) ixwayise ngokuthi izimo ze-La Niña ezingathathi hlangothi nezibuthakathaka kakhulu kulindeleke phakathi nengxenye yokuqala ka-2017. Nakuba isimo kungenzeka sishintshe kusukela ngoMeyi. Ukuze uthole ulwazi olwengeziwe mayelana nezici zalesi simo, ungabheka isihloko esithi Iyini i-La Niña phenomenon?.
Ukuze wazi isenzo salezi zenzakalo, i-WMO isuselwa ekutadisheni nasekudalweni kwamamodeli abikezela lezi zenzo. Ngemuva kokuzihlaziya, bafinyelele esiphethweni sokuthi kungenzeka ukuthi izimo zezemvelo ezingathathi hlangothi zigcinwa noma ngabe isimo se- "La Niña" singama-70-85%.
Isimo se- "La Niña"
Ukuze sibeke lolu lwazi kumongo, ake sibuyekeze kafushane isenzakalo sase-La Niña. Lesi simo siqala lapho isigaba esihle se-Southern Oscillation sifinyelela emazingeni abalulekile futhi sihlala izinyanga ezimbalwa.
Lapho u- "La Niña" ekhona, umfutho wezinga lolwandle wehla esifundeni sase-Oceania, futhi kubangela ukwanda okufanayo ePacific eshisayo neshisayo eduze nogu lwaseNingizimu Melika naseMelika Ephakathi; okuholela ekwenyukeni komehluko wengcindezi okhona phakathi kwamaphethelo womabili we-equatorial Pacific. Imimoya yohwebo iyaqina, iletha amanzi ajulile apholile uma kuqhathaniswa eduze nenkabazwe Pacific phezulu. Ukuze uqonde kangcono imiphumela yayo, ungabheka isihloko esithi imiphumela ye-La Niña phenomenon.
Le mimoya enamandla ngokweqile iba namandla amakhulu okuhudula ebusweni bolwandle, ikhuphule umehluko olwandle phakathi kwemikhawulo yomibili ye-Pacific esenkabazwe. Ngalokhu, ulwandle luyancipha ogwini lwaseColombia, e-Ecuador, ePeru nasenyakatho yeChile futhi luyanda e-Oceania. Njengomphumela wokuvela kwamanzi abandayo uma kuqhathaniswa ne-Equator, izinga lokushisa lolwandle lehla ngaphansi kwesilinganiso sesimo sezulu. Ngalo mqondo, kubalulekile ukuqaphela lokho Intombazane kungaba nomthelela omkhulu esimweni sezulu.
Amazinga okushisa ePacific
Phakathi nengxenye yesibili ka-2016, amazinga okushisa angaphezulu oLwandlekazi iPacific ayesemkhawulweni womkhawulo ohlukanisa izimo ezibandayo nezingathathi hlangothi. Manje, ekuqaleni kuka-2017, la mazinga okushisa namanye amasimu asemkhathini abuyele ngokusobala emazingeni angathathi hlangothi, ngakho-ke umphumela we "La Niña" awenzeki. Lezi zinkomba zenza izazi zezulu zicabange ukuthi lezi zimo izohlala izinzile phakathi nengxenye yokuqala yonyaka wezi-2017.
Umehluko wokuthi amazinga okushisa embulunga yonke athintana kanjani ukuthi i-El Niño iwabangela ukuba anyuke futhi iLa Niña iwabangela ehle. Ngaphezu kwalokho, i-“La Niña” yandisa imvamisa yeziphepho e-Atlantic Ocean, ehlobene nocwaningo lwezindlela zesimo sezulu I-Atlántico. Kuyafaneleka futhi ukusho lokho imiphumela yokupholisa kwe-Atlantic zibalulekile kulo mongo.
Engxenyeni yesibili yowezi-2017
Ngoba lezi zimo azihlali zizinzile kangako, amamodeli enziwa afaka izinto eziguquguqukayo lapho lezi zinto zenzeka khona. Lokhu kuqagela okwenziwe amamodeli we-WMO ngemuva kukaMeyi 2017, kufaka phakathi amathuba amaningi. Izimo ezibandayo kungenzeka zenzeke, zihambisane nalezo ezinikezwa yi- "La Niña" kepha nezimo ezingathathi hlangothi kuze kube ukwakhiwa okulandelayo kwesiqephu se- "El Niño".
Ngengxenye yesibili ka-2017, izimo ze-La Niña ezingathathi hlangothi cishe zizoqhubeka. ethubeni elingu-50%., inhlangano ibonisa, exwayisa, nokho, ukuthi amathuba okuba isiqephu se-"El Niño" sakheke phakathi nekota yesithathu noma yesine ka-2017 "abalulekile," emi cishe ku-35 noma 40%.
Imijikelezo ka-“El Niño” ivamise ukuba njalo eminyakeni eyi-7. Nokho, ngenxa yokushintsha kwesimo sezulu, le mijikelezo yenzeka kakhulu futhi kaningi. Ukuze uthole imininingwane eyengeziwe, ungabheka isihloko ku ubuthakathaka obungenzeka beLa Niña.
