Alamun Yanayi na Duniya

**Alamun paleoclimate na duniya** sune masu saurin ji ga canje-canjen yanayin paleoclimatic na duniya. Yawancin su an samo su ne daga ruwan da ke cikin ruwa. Alamun Paleoclimate da aka samo daga turɓaya na ƙasa, a gefe guda, galibi suna rinjayar motsi na gida da bambancin paleogeographic. Abubuwan da ke kula da tsarin yanayi na Duniya sun haɗa da tectonics na farantin, wanda ke sarrafa tsarin nahiyoyi, hulɗa tsakanin yanayi da teku, da halaye na duniya (Milankovitch cycles). An kafa alamun paleoclimate na duniya bisa ga bayanan da aka cire daga nazarin kayan ilimin ƙasa, gami da bayanan halitta, geochemical da ma'adanai da aka adana a cikin ruwa. Ana rarraba masu nunawa zuwa kashi uku; paleontological, geochemical da lithological.

## Alamun paleontological
Rubutun sedimentary suna da tasiri ta hanyar hoto na gida da na teku da na yanayi. Abubuwan da ke da mahimmancin yanayin yanayi na duniya, duk da haka, ba su da ma'ana a fassarar yanayin zafi. Marine biota sun bayar da nisa mafi yawan proxies ga paleotemperature, wanda microfossils, saboda tartsatsi, yalwa da kuma kula da latitude canje-canje, sun bayar da yawa na farko muhimman paleotemperature Manuniya. Gane nau'in fihirisar latitude yawanci shine ƙoƙari na farko na ɗaure kasancewarsu a cikin sediments zuwa canjin yanayin zafi. Sauran kaddarorin biota na ruwa, gami da ilimin halittar jiki, yalwa, bambance-bambance, da ilimin kimiyyar lissafi suma an samu nasarar kafa su azaman alamomin burbushin halittu. Ƙididdigar ƙididdigar ƙididdiga masu rikitarwa (binciken factor, babban sashi, da sauransu) na tarihin tarihin rayuwa sun sami damar haɗa tarukan fauna da yawan ruwa don sake gina paleo-na yanzu. Jerin da ke ƙasa akwai wasu mahimman kayan aikin burbushin halittu waɗanda masana kimiyya ke amfani da su don sake gina tarihin yanayin zafin jiki.

#### Yanayin Yanayi

##### Girma
Bincike na yawan planktonic foraminiferal ya nuna cewa nau'in wurare masu zafi sun kai girman gwajin su mafi girma a cikin ruwan zafi, kuma nau'in polar sun kai matsakaicin girman a cikin ruwan polar. Dabbobi da ke zaune a cikin ruwa mai zafi da ruwa mai zurfi suna raguwa a girman gwaji tare da karuwa da raguwar zafin jiki.

Girman proloculus (ɗaki na farko) na forams na benthic yana shafar zafin ruwan teku kuma an yi amfani da matsakaicin su azaman wakili don binciken paleoclimatic.

An yi amfani da matsakaicin gwajin gwajin planktonic foraminifer Orbulina universa don fassara tarihin zafin jiki na teku a cikin Basin Somaliya. R-mode factor da Q-mode cluster analysis sun bayyana manyan abubuwa guda biyar da kuma clusters biyar nuna daban-daban muhalli halaye, gami da kara oxygenation, high surface productivity.

##### Hanyar juyawa
An ambaci forams da yawa don samun hanyoyi daban-daban na juyawa don mayar da martani ga zafin jiki. Globierina pachyderma, alal misali, yana nuna yawan jama'a na dama a cikin ruwa mai sanyi vs. hagu a cikin ruwa ozu,  kuma an yi amfani da rabo na waɗannan siffofin biyu don kimanta yanayin zafi.  An bayar da rahoton irin wannan dogaro da jagororin juyawa akan yanayin zafi ga Muricohebergella delrioensis a cikin sediments na Cretaceous . 

Globigerina bulloides, wani benthic foram, an rubuta shi don hanyoyin da ke da alaƙa da yanayin zafi na ruwan teku a cikin turɓaya na kudancin Tekun Indiya.

An rubuta irin wannan dangantakar don wani benthic foram Bulinina marginata . 

#### Bambancin nau'o'i
Bambancin nau'ikan foraminiferal na Planktonic ya dogara da wuraren da ke akwai, waɗanda ke da alaƙa da yaduwar teku. Ta hanyar alaƙa da rikodin isotope mai ɗorewa, an sami matsakaicin bambancin ya faru bayan farawar lokacin glaciation.

#### Tarihin rayuwa
Tun lokacin da zurfin teku ya zama samuwa a cikin shekarun 1960, an yi amfani da alamun paleoclimatic na planktonic foraminifera daga ruwan teku don sake gina paleoclimate. Daga cikin majagaba na farko don amfani da wadataccen latitudinal foraminifera, Ericson da Wollin (1968) sun yi nasara wajen kafa sake zagayowar glacial da Interglacial na Pleistocene bisa ga rabo na nau'in ruwa mai sanyi da mai dumi a cikin turɓaya mai zafi. Kennett (1970), wanda, bisa ga nau'in foraminferal na sanyi da ruwan dumi, ya sake gina canje-canjen paleoclimatic a cikin Pleistocene, daidai da yanayin da aka kafa a yankin wurare masu zafi.

Lokacin da ake hakowa, wanda ya dawo da ginshiƙai masu tsawo fiye da piston, ya zo, an tura binciken sake fasalin paleoclimatic a lokutan geological. An gina yanayin yanayi a cikin Oligocene a cikin Gulf of Mexico ta hanyar amfani da alamun ruwa mai dumi (Turborotalia pseudoampliapertura, Globoquadrina tripartita, Dentoglobigerina globularis, Dentglobigerina baroemoenensis, "Globigerina" ciperoensis da Globigerinoides, da kuma Cassigerinella chipolensis) da alamun ruwan sanyi (Catapsydrax spp., Globorotaloides spbotp., Subs, sitel, stripgerides da Globi. Spezzaferri ya binciki wani yanki mai zurfi a cikin 1995, wanda ya bincika samfurori daga ƙwayoyin hako a cikin Tekun Atlantika, Indiya da Kudancin Pacific kuma ya gano kuma ya haɗa foraminifera a cikin ƙididdigar zafi, sanyi, zafi da sanyi. An kafa tsarin yanayi na paleoclimatic a cikin lokacin canjin Oligocene da Miocene kuma bayanan isotope sun goyi bayan tsarin.

Hanyar da ta fi dacewa don sake gina yanayin yanayi ya haɗa da amfani da bincike. Thompson (1981) ya sami damar danganta tarurruka shida na foraminiferal daga samfurori na farko don gabatar da ruwa a yammacin Arewacin Pacific. An samar da aikin canja wurin don haɗa tarurruka zuwa yanayin zafi na teku. An sake gina tsarin yanayin yanayi na shekaru 150,000 da suka gabata ta hanyar amfani da wannan aikin canja wurin ga tsoffin turɓaya a cikin ƙwayoyin.

An yi amfani da irin wannan dabarar ga Eocene da Oligocene kuma an rarraba forams a cikin farfajiyar, matsakaici da zurfin ruwa. Ta haka ne aka sake gina nau'ikan ruwa, ban da sauye-sauyen yanayin yanayi.

### Coccolith
An lura da canjin digiri 15 na latitude don rarraba wasu nau'ikan da aka zaɓa na Coccolits tsakanin abubuwan da suka faru a baya-bayan nan da kuma abubuwan da suka dace a tsakiyar Wisconsin na Arewacin Atlantic. Haɗuwa da coccoliths a cikin ruwa na ruwa ya bayyana yana da alaƙa da yanayin zafi. Wannan an nuna shi ta hanyar bincike mai yawa na tarin coccolith a yammacin Bahar Rum Pleistocene.

### Masu amfani da rediyo
Saboda tsayayyarsu ga rushewar ruwan sanyi, wanda ke lalata burbushin planktonic na calcareous a zurfin duniya, Radiolarians ya zama ɗaya daga cikin burbushin siliceous planktonics da aka fi nazarin don sake fasalin paleotemperature. Nazarin Radiolarians a cikin zurfin teku na Arewacin Pacific ya nuna cewa karuwa a cikin nau'o'in jinsuna da yawa da suka dace da manyan abubuwan da suka faru na glaciation na shekaru miliyan 16 da suka gabata. Canje-canje a cikin abubuwan da ke cikin Radiolarian suna bayyane don nunawa a cikin zafin jiki na teku gaba ɗaya.

Ta hanyar amfani da nazarin kididdiga (Q-mode factor analysis), yawancin nazarin ƙididdigar ƙididdigat na Radiolarian daga turɓaya na ƙasa sun kafa aikin canja wurin wanda ke ba da damar kimanta yawan zafin jiki na paleo-sea. Misali, Pisias et al. (1997) sun sami damar gano tarin da ke wakiltar tarihin rayuwa na yanzu na Pacific kuma sun yi amfani da waɗannan tarin don hango hasashen zafin teku na iyakar glacier na ƙarshe.

## Manazarta