Ƙididdigar ENSO mai yawa

Alamar ENSO mai yawa, wanda aka taƙaita a matsayin MEI, hanya ce da aka yi amfani da ita don bayyana tsananin taron El Niño Southern Oscillation (ENSO). Ganin cewa ENSO ya samo asali ne daga hadaddun hulɗa na tsarin yanayi iri-iri, ana ɗaukar MEI a matsayin mafi girman ƙididdiga don saka idanu kan ENSO tunda ya haɗu da nazarin abubuwa masu yawa na yanayin yanayi  na teku.

## Bayani na gaba ɗaya
MEI an ƙaddara shi a matsayin babban bangare na farko na sigogi daban-daban guda shida: matsin lamba na teku, bangarorin yanki da na meridional na iska, zafin jiki na teku, zafin iska da girgije ta amfani da bayanai daga International Comprehensive Ocean-Atmosphere Data Set (ICOADS). [1] MEI ana lissafa shi sau goma sha biyu a kowace shekara don kowane "lokaci mai saukowa na wata biyu", wanda aka kwatanta da Janairu-Fabrairu, Fabrairu-Maris, Maris-Afrilu, da sauransu.[1] Babban dabi'un MEI masu kyau suna nuna bayyanar yanayin El Niño, yayin da manyan dabi'unMEI marasa kyau suna nuna faruwar yanayin La Niña.[1]￼

## Ƙarin MEI
Duk da yake Hukumar Kula da Tekun Kasa da Yanayi (NOAA) ta rubuta dabi'un MEI daga 1950 zuwa yanzu, masu bincike daban-daban sun ambaci bukatar bayanai kafin 1950 don inganta halayyar ENSO ta al'ada da abubuwan da ba a saba gani ba waɗanda zasu iya zama sakamakon canjin yanayi. A cewar wasu kafofin, ba daidai ba ne a yi ƙoƙari a lissafa MEI kafin 1950 saboda ma'aunin muhalli ba abin dogaro ba ne a lokacin Yaƙe-yaƙe na Duniya kuma akwai juyin juya hali a kusan dukkanin hanyoyin ma'auni na yanayi a kan jiragen ruwa a cikin shekarun 1940. Koyaya, an halicci wani tsari da aka sani da "Extended MEI" ko "MEI.ext" wanda ke kimanta ƙimar MEI tun daga shekara ta 1871. An kammala wannan ta hanyar amfani da bayanan da aka sake ginawa akan matsin lamba na teku da zafin jiki na teku, abubuwan biyu da ake zaton sun fi tasiri ga ƙayyade MEI. Shirye-shiryen da ke kwatanta dabi'un MEI.ext sun nuna cewa bayanai daga hanyoyin biyu suna da alaƙa sosai, suna tallafawa daidaito da tasirin MEI. ext.

## Sauran alamomi

### Kudancin Oscillation Index
An lissafa Southern Oscillation Index (SOI) bisa ga bambancin matsin lamba tsakanin Tahiti da Darwin, Australia. Duk da cewa ana amfani dashi akai-akai a cikin karatun ENSO, ba a dauke shi abin dogaro kamar MEI ba saboda yana la'akari da canjin muhalli guda ɗaya kawai.

### Yaro 3.4 SST

Kamar SOI, Niño 3.4 SST yana amfani da siginar daya - zafin jiki na teku - don nuna ENSO. Yankin Niño 3.4 SST (yanki masu mamayewa 3 da 4, duba taswirar) ya ƙunshi ma'aunin zafin jiki daga tsakanin 5 ° N - 5 ° S da 120 ° - 170 ° W.

### Ƙididdigar ENSO da aka haɗa
The Coupled ENSO Index (CEI) yana amfani da haɗuwa da SOI da Niño 3.4 SST don lissafin duka sassan yanayi da na teku.

### Ƙididdigar ENSO ta tushen wakili
An haɓaka ta Braganza, da sauransu, 2009, wannan alamar tana amfani da murjani, zoben itace da bayanan kankara don nuna abubuwan da suka faru na ENSO daga 1525 - 1982. Bayanan wakili na ENSO ya rufe yanki mai faɗi a fadin Pacific, kuma ya haɗa da bayanai daga yamma da tsakiyar Pacific, New Zealand, da kuma yankin Arewacin Amurka. Kodayake ƙididdigar ENSO ta rufe babban sikelin lokaci sama da ƙarni huɗu, tana nuna babban alaƙa (> 40%) tare da SOI, Niño 3.4 SST da CEI, yana nuna daidaito da amfani.

## Manazarta