“Isimo sezulu siyahlanya” mhlawumbe inkulumo eyichaza ngokunembe kakhulu izimo zezulu eziba yinkimbinkimbi esizibonayo. Unyaka ngamunye, sibekezelela ihlobo elishisa kakhulu kunawo wonke emlandweni, kodwa futhi sibhekana nosongo lwesithwathwa, imvula enamandla kakhulu, nezinhlekelele zemvelo ezikhulayo njengeziphepho neziphepho. Sekuyiminyaka eminingi kukhulunywa ngezinga lokushisa elingavamile e-Atlantic, okwakubonakala kungashintshile. Nokho, ukuqaphela kwakamuva okwenziwa ososayensi ezinyangeni ezintathu ezedlule kwembula inkambiso emangalisayo: i-Atlantic iyaphola ngempela.
Kulesi sihloko sizokutshela Imiphi imiphumela okuba nayo ukupholisa okuseduze kwe-Atlantic?.
Impicabadala ezungeze ukupholisa okusheshayo kwe-Atlantic
I-Atlantic Ocean, ebhekwa njengenye yezindawo ezibhekwa futhi ezicwaningwa kakhulu zamanzi emhlabeni, ivumela ngisho nezinguquko ezincane kakhulu ukuthi zitholwe kalula. Ngakho-ke, ukuguquguquka kwerekhodi okwethusayo kuphakamisa ukukhathazeka emphakathini wesayensi, njengoba lezi zinguquko zingathinta kakhulu izinhlelo zesimo sezulu somhlaba wonke, kodwa futhi nemvamisa kanye nokuqina kwezehlakalo zesimo sezulu njengeziphepho. Lona umkhuba okhulayo, ofana nalowo we "Atlantic Niña".
Kuwo wonke umlando, kuye kwaphawulwa lokho Ukufudumala kwembulunga yonke kuthinta ngqo izilwandle, okuholela ekwenyukeni kwezinga lokushisa kwamanzi angaphezulu, umkhuba owawubikezelwe kakade. Nokho, i-Atlantic iyayibekela inselele le phethini. Kunokuba zihlale zifudumala, izindawo ezithile zolwandle zihlangabezana nenqubo ekhathazayo yokupholisa, into ehlala ingaqondakali kososayensi.
INorth Atlantic ingesinye sezifunda ezithinteke kakhulu kulo mkhuba wokupholisa, nokwehla kwezinga lokushisa okuphawulekayo okubonwe eminyakeni yamuva nje. Nakuba eminye imibono iphakamisa ukuthi izinguquko emisinga yolwandle, ukuhamba kwamanzi noma ngisho nokuncibilika kweGreenland kungase kube nomthelela kulesi simo, asikho isivumelwano esiqondile esisafinyelelwe. Nokho, inkinga ecindezela kakhulu ukuthi, njengoba uPedro DiNezio weNyuvesi yaseColorado eBoulder ebonisa, lokhu kuguquka kwezinga lokushisa sekuqale ukubonakala e-equatorial Atlantic (ezindaweni ezishisayo) kusukela ngoMeyi.
Nakuba ukushintsha kwezinga lokushisa elivamile kubonakala, Indawo ethize ethile yokukhathazeka okukhulayo umugqa omncane ogudle i-Equator, eduze nogu lwase-Afrika. Kuyaphawuleka ukuthi lesi sifunda siye sabhekana noshintsho olushesha kakhulu olwake lwabhalwa. Ukupholisa kwehlobo kwalawa manzi kuwumphumela wemimoya yohwebo ebheke ngasentshonalanga, evame ukuqina phakathi nalesi sikhathi njengoba ibhande elincane leziphepho ezishisayo liya enyakatho. Ukushisa kolwandle kushabalaliswa kancane ngokusebenzisana kwale mimoya namanzi.
Kuthinta isimo sezulu somhlaba
Isimo sezulu somhlaba wonke sithinteka kakhulu, ikakhulukazi ukwakheka kweziphepho. Lezi ziphepho zithola amandla azo ekushiseni kolwandle, okusho ukuthi ukushintshashintsha kwezinga lokushisa kwamanzi angaphezulu kungaba nomthelela omkhulu ekuziphatheni kwazo. I-Atlantic ebandayo inganciphisa amandla atholakala eziphepho, okubangela iziphepho ezinamandla. Kodwa-ke, ezinye izakhi, okuhlanganisa izinguquko ezindleleni zomoya kanye namazinga omswakama, nazo zibalulekile ekuthuthukisweni kwalezi zimo zezulu.
Ukwengeza, ukwehla kwezinga lokushisa lase-Atlantic kungaba nemiphumela efinyelela kude esimweni sezulu somhlaba. Njengengxenye ebalulekile yomjikelezo we-thermohaline, i-Atlantic Ocean isebenza njengesistimu yokusabalalisa ukushisa okukhulu emhlabeni jikelele. Uma i-Atlantic iphola, lokhu kusakazwa kungashintshwa, kube nomthelela kumaphethini wesimo sezulu eYurophu, eNyakatho Melika nakwezinye izifunda ezimbalwa. Ngenxa yalokho, ezinye izindawo zingabhekana nobusika obuqinile, kuyilapho abanye bebona izimo zasehlobo ezifudumele noma ezomile.
Okuwukuphela kokucatshangelwa okungenziwa ukuthi nakuba iPacific La Niña ngokuvamile ihambisana nezimo ezomile entshonalanga ye-United States kanye nemvula eyengeziwe empumalanga ye-Afrika, i-Atlantic La Niña cishe izonciphisa imvula esifundeni sase-Sahel e-Afrika futhi ikhulise ezindaweni ezithile zaseBrazil. Nokho, kunesizathu sokuba nethemba lokuthi ukuba khona kwe-Atlantic La Niña kungase kuhlehlise ukuqala kwePacific La Niña.
Imithelela eziqhingini zaseBalearic
Ukukhathazeka okukhulu kuye kwaphakama emphakathini wesayensi mayelana nokuwa okungenzeka kwe-Gulf Stream, njengoba kuqokonyiswe ocwaningweni olushicilelwe kumagazini i-Science Advances. Uprofesa we-Earth Physics e-University of the Balearic Islands (UIB) kanye nomqondisi we-Interdisciplinary Laboratory of Climate Change (LINCC), u-Damià Gomis, uhlaziye imithelela engenzeka yalesi simo eziqhingini zaseBalearic. Ukwehliswa kwemisinga yase-Atlantic kungadala ukupholisa kulo lonke elaseYurophu., nakuba imiphumela ingahluka phakathi kwezifunda ezisenyakatho neMedithera. E-Scandinavia, izinga lokushisa lasebusika lingehla liye ku-30°C (cishe u-10°C ehlobo), kuyilapho. EMedithera kuzoba khona ukwehla kwasebusika okungu-3-4ºC kanye nokwehla kwehlobo ngo-1-2ºC.
Kubalulekile ukuqaphela ukuthi ukupholisa okuphawuliwe kubangelwa ngokuphelele ukuwa kwe-AMOC futhi kufanele kucatshangelwe eduze nokufudumala kwembulunga yonke okubangelwa ukukhuphuka kwamazinga e-CO2 emkhathini. Eziqhingini zaseMedithera naseBalearic, umphumela womhlaba wonke ungasondela ku-zero, kuya ngomkhondo wokuphuma kwegesi ebamba ukushisa.
Izinguquko eziphawulekayo emazingeni
Mayelana nemvula, ukuwa kwe-AMOC kungabangela izinguquko ezinkulu kumaphethini ayo. EYurophu, lokhu kungasho ukwehla ngo-10% ebusika kanye no-30% ehlobo. Sengiphetha, iziqhingi zaseBalearic zizobhekana nemiphumela emikhulu, okuhlanganisa ukwehla kwezinga lokushisa lasebusika kanye nezinguquko zamaphethini emvula. Umphumela usuwonke wokupholisa okubangelwa ukwehluleka kwe-AMOC, kanye nokufudumala kwembulunga yonke, kuzoncika esimweni sokukhishwa kwesisi esibamba ukushisa.
Ucwaningo lwangaphambilini lwaluxwayise mayelana nokwenzeka kokuwa kwe-AMOC, ukulinganisa ukuthi kungenzeka phakathi kuka-2025 no-2095. Nokho, ucwaningo olusha olwenziwa abacwaningi base-Utrecht ngolokuqala ukuveza ukuba khona kwephuzu lokungabuyi; Ukweqa lo mkhawulo kuzokwenza ukuwohloka kwesistimu kungenzeki.
Amathuba okufinyelela kuleli phuzu elibalulekile phakathi kuka-2025 no-2095 alinganiselwa ku-95%, ephakeme kakhulu kunezibikezelo ezenziwe emibikweni ye-IPCC. Ngaphezu kwalokho, ucwaningo lukhomba ukuthi ukuwa kungenzeka ngaphambi kwesikhathi ebesilindelekile, okuzoholela ekutheni kube nomphumela wesimo sezulu kancane kancane ongabonakala ekwehleni kwezinga lokushisa enyakatho yeYurophu.
