“Ulimi olubandayo” luyisiqhingi esipholile e-Pacific Ocean ngasogwini lwase-Ecuador. Okuwukuphela kwengxenye yezilwandle zomhlaba ezophola, kuyimpicabadala engadlala indima ebalulekile ekuguquguqukeni kwesimo sezulu.
Izilwandle ziyafudumala ngenxa isimo sezulu shintsha: yilokho ososayensi abebesitshela khona iminyaka. Ngenkathi uLwandle iMedithera kanye neNyakatho ye-Atlantic zibeka amarekhodi aphelele okufudumala, i-anomaly isaqhubeka: indawo yoLwandlekazi iPacific okuthi, ngokumelene nawo wonke umqondo, iphole. Futhi sekuyiminyaka engamashumi amathathu edlule. Imfihlakalo yangempela, echazwe “njengombuzo ongaphenduliwe obaluleke kakhulu emkhakheni wesimo sezulu” nguchwepheshe we-University of Colorado uPedro DiNezio, okwaxoxwa naye nabezindaba. New Scientist, ekhuluma ngesihloko esithi “ulimi olubandayo” lwasePacific.
Eyokugcina, eyatholwa ngawo-1990 futhi inweba ngaphezu kwamakhilomitha ayizinkulungwane ezimbalwa. Isikhathi eside, kwakubangelwa ukwehluka kwemvelo okwedlulele kwesifunda: ulwandle olukhulu nolujule kakhulu emhlabeni, oluhlale lupholile kakhulu (5 kuya ku-6 ° C) ohlangothini olusempumalanga, noma ugu oluseNtshonalanga. Amazwe aseMelika ohlangothini lwase-Asia, kunasohlangothini lwaseNtshonalanga. Kodwa abanye ososayensi, abanjengoRichard Seager waseColumbia University eNew York, baye babonisa ukuthi lokhu kupholisa kancane kancane kwakungeyona ngempela into engokwemvelo, nokuthi kungase kube ngenxa yezinye, namanje ezingaziwa, izenzakalo ezihlobene ‘nomsebenzi womuntu. Inkinga ilapho: lolu limi olubandayo luyancipha amadigri (0.5°C eminyakeni engu-40) futhi namanje asazi ukuthi kungani, nakuba sesineminyaka engu-30 silubona. Ngaphandle kokuthi lesi simo singaba nemiphumela emibi kakhulu, imodeli yamanje yesimo sezulu engayinaki, njengoba kubikwa abezindaba zesayensi.
Inkinga ukuthi ukungazi ukuthi kungani lokhu kupholisa kwenzeka kusho ukuthi nathi asazi ukuthi kuzoma nini, noma kuzophenduka kungazelelwe kufudumale. Lokhu kunemiphumela yomhlaba wonke. Ikusasa lolimi olubandayo linganquma ukuthi iCalifornia ikhungethwe yisomiso esingapheli noma i-Australia imililo yequbula ehlala ibulala kakhulu. Inomthelela ekushubeni kwenkathi yezimvula ezinkulu eNdiya kanye namathuba endlala oPhondweni lwase-Afrika. Ingashintsha ngisho nezinga lokushintsha kwesimo sezulu emhlabeni wonke ngokulungisa ukuthi umkhathi womhlaba uzwela kangakanani ekukhuphukeni kwesisi esingcolisa umoya.
Uma kubhekwa konke lokhu, akumangazi ukuthi ososayensi besimo sezulu bazama ukuthola ukuthi kuqhubekani ngokukhulu ukuphuthuma.
IPacific, inkulu kunazo zonke izindawo zomhlaba
Ulwandlekazi lwasePacific luhlala lungaqondakali, luwulwandle olukhulu futhi lujule kakhulu emhlabeni - lukhulu kangangokuthi luhlanganisa indawo enkulu kunawo wonke umhlaba ohlangene. Ukushintshashintsha okukhulu kwemvelo kwesimo sezulu sasePacific eshisayo kuthonya isimo sezulu somhlaba wonke, ukwazi ukuthi sizosabela kanjani ekwandeni kokukhishwa kwamagesi abamba ukushisa emkhathini kuyinselele enkulu.
Cishe njalo eminyakeni emithathu kuya kwemihlanu, iPacific isuka esiqeshini seLa Niña, esinamanzi okushisa apholile uma kuqhathaniswa endaweni yenkabazwe, siye esiqeshini se-El Niño, lapho la manzi efudumala ngaphezu kokuvamile. Lo mjikelezo, obizwa ngokuthi i-El Niño Southern Oscillation, noma i-ENSO, ubangelwa izinguquko emaphethini omoya wolwandle kanye nokuhamba kwamanzi kusuka endaweni ebandayo yolwandle eya endaweni efudumele.
Okungezwe kukho i-Pacific decadal oscillation (PDO), ukushintsha kwezinga lokushisa kwamanzi olwandle esikhathini esiyiminyaka engama-20 kuya kwengama-30, umsuka wayo oqondile ohlala ungakaziwa, kanye nemiphumela yayo efana naleyo ye-ENSO.
Indlela ebangela i-PDO. ayikaqondwa kahle. Kuye kwasikiselwa ukuthi ungqimba olungaphezulu oluncane olufudumala ehlobo phezu kolwandle luvikela amanzi abandayo ekujuleni futhi kuthatha iminyaka ukukhuphuka.
Imiphumela yezigaba ezibandayo nezifudumele ibonakala esimweni sezulu saseNyakatho Melika. Phakathi kuka-1900 no-1925, phakathi nenkathi yokubanda, amazinga okushisa onyaka ayephansi uma kuqhathaniswa. Phakathi neminyaka engamashumi amathathu eyalandela kanye nesigaba esifudumele, amazinga okushisa ayebanda. Umjikelezo waqinisekiswa isikhathi ngasinye ngemva kwalokho
Lokhu kuhlukahluka kwenza kube nzima ukubalwa kwamathrendi esikhathi eside. Kungakho, lapho bethola lesi simo “solimi olubandayo” ngeminyaka yawo-1990, abacwaningi bathi ubukhona baso bubangelwa ukwehluka okwedlulele (kodwa kwemvelo) kwesifunda.
