Bayani na Ice-albedo

**Sakamakon Ice-[[albedo]]** shine ra'ayi na canjin yanayi, inda canji a yankin kankara, ƙanƙara, da kankara ta teku ke canza albedo da zafin jiki na Duniya. Saboda kankara tana nunawa sosai, tana nuna karin Hasken rana zuwa sararin samaniya fiye da ruwa mai budewa ko wani murfin ƙasa. Yana faruwa a Duniya, kuma yana iya faruwa a kan taurari masu banƙyama.

Tunda manyan latitudes suna da mafi kyawun yanayin zafi, sune yuwuwar samun murfin dusar ƙanƙara na shekara-shekara, dusar ƙanƙara mai yaduwa da iyakoki - har zuwa kuma gami da yuwuwar samar da zanen kankara .  Duk da haka, idan dumamar yanayi ta faru, to, yanayin zafi mai girma zai rage yankin da kankara ya lullube, kuma ya fallasa karin ruwa ko ƙasa. Albedo yana raguwa, don haka ƙarin makamashin hasken rana yana sha, yana haifar da ƙarin ɗumamawa da mafi girman asarar sassan da ke nunawa na cryosphere . Sabanin haka, yanayin sanyi yana ƙara murfin kankara, wanda ke ƙara albedo kuma yana haifar da sanyaya mafi girma, wanda ke sa ƙarin samuwar ƙanƙara mai yuwuwa. 

Don haka, ra'ayoyin kankara-albedo suna taka muhimmiyar rawa a Canjin yanayi na duniya. Yana da mahimmanci ga farkon yanayin Snowball Earth kusan shekaru miliyan 720 da suka gabata kuma don ƙarshen su game da 630 mya:  deglaciation mai yiwuwa ya haɗa da duhu sannu a hankali na albedo saboda haɓaka ƙura.  A cikin ilimin ƙasa da ya gabata, wannan ra'ayi ya kasance babban abu ne a cikin ci gaban kankara da kuma janyewa a lokacin Pleistocene (~ 2.6 Ma zuwa ~ 10 ka da suka gabata).  Kwanan nan, karuwar da mutum ya haifar a cikin hayakin gas din ya sami tasiri da yawa a duk faɗin duniya, kuma raguwar kankara na teku na Arctic ya kasance daya daga cikin mafi bayyane. Yayin da kankara ta teku ke raguwa kuma tana nuna karancin hasken rana, Arctic yana da zafi har zuwa sau hudu fiye da matsakaicin duniya. A duniya, asarar kankara na tsawon shekaru a cikin Arctic da raguwar kankara na teku a cikin Antarctica sun sami tasirin dumama iri ɗaya tsakanin 1992 da 2018 kamar yadda 10% na duk iskar gas ɗin da aka fitar a wannan lokacin.

Ra'ayin Ice-albedo ya kasance a cikin wasu samfuran yanayi na farko, don haka suna kwaikwayon waɗannan tasirin da aka lura shekaru da yawa.   Saboda haka, hasashensu game da ɗumamar nan gaba kuma sun haɗa da asarar ƙanƙara a nan gaba tare da sauran masu haɓaka canjin yanayi.  An kiyasta cewa asarar ci gaba a lokacin rani na Arctic, lokacin da Rana ke haskakawa sosai kuma rashin yanayin haske yana da tasiri mafi girma, zai haifar da dumamar yanayi a kusa da  .   Har ila yau, akwai ƙididdiga na ƙididdiga na tasirin dumamar yanayi daga asarar dusar ƙanƙara da dusar ƙanƙara a Greenland da Antarctica . Duk da haka, ɗumamar asararsu gabaɗaya ya fi na ƙanƙarar ƙanƙara da ke raguwa, kuma zai ɗauki lokaci mai tsawo kafin a gan shi.  

## Binciken farko

A cikin 1950s, farkon masana yanayin yanayi irin su Syukuro Manabe sun riga sun yi ƙoƙarin bayyana rawar da murfin kankara ke yi a cikin kasafin makamashi na duniya .  A cikin 1969, duka USSR 's Mikhail Ivanovich Budyko da Amurka ' William D. Masu siyarwa sun buga takardu da ke gabatar da wasu nau'ikan nau'ikan yanayi na farko na makamashi-ma'auni don nuna cewa tasirin kankara yana da tasiri mai mahimmanci akan yanayin duniya, kuma cewa canje-canje zuwa murfin dusar ƙanƙara a kowane bangare na iya yin aiki azaman amsa mai ƙarfi.    

Ba da daɗewa ba an gane wannan tsari a matsayin wani muhimmin ɓangare na ƙirar yanayi a cikin bita na 1974,  da kuma a cikin 1975, tsarin kewayawa na gabaɗaya wanda Manabe da Richard T. Wetherald suka yi amfani da shi don kwatanta tasirin maida hankali na CO  sau biyu a cikin yanayi - ma'auni mai mahimmanci na yanayin yanayin yanayi - ya riga ya haɗa da abin da aka bayyana a matsayin "ma'anar murfin dusar ƙanƙara".  Ra'ayin Ice-albedo yana ci gaba da haɗawa a cikin samfuran da suka biyo baya.  Ana kuma amfani da lissafin ra'ayoyin ga nazarin paleoclimate, irin su na lokacin Pleistocene (~ 2.6 Ma zuwa ~ 10 ka ago). 

## Matsayi na yanzu

Dusar ƙanƙara-da ƙanƙara-albedo ra'ayoyin suna da tasiri sosai akan yanayin zafi na yanki. Musamman kasancewar murfin dusar ƙanƙara da ƙanƙarar teku ya sa yankin Arewa da Kudancin Kudancin ya fi sanyi fiye da yadda za su kasance ba tare da shi ba.  Sakamakon haka, raguwar ƙanƙarar tekun Arctic na baya-bayan nan shine ɗayan abubuwan farko da ke bayan ɗumamar Arctic kusan sau huɗu cikin sauri fiye da matsakaicin duniya tun 1979 (shekarar da ci gaba da karatun tauraron dan adam na kankarar Arctic teku ya fara), a cikin wani sabon abu da ake kira Arctic amplification . 

Nazarin ƙirar ƙira ya nuna cewa haɓakar Arctic mai ƙarfi yana faruwa ne kawai a cikin watanni lokacin da babban asarar kankara ta teku ke faruwa, kuma yana ɓacewa sosai lokacin da aka daidaita murfin kankara.  Sabanin haka, babban kwanciyar hankali na murfin kankara a Antarctica, inda kauri na kankara na Gabashin Antarctic ya ba shi damar tashi kusan 4.&nbsp;kilomita sama da matakin teku, yana nufin cewa wannan nahiya ta ɗan sami ɗumamar ɗumamar yanayi a cikin shekaru 70 da suka gabata, wanda galibin abin da ya ta'allaka ne a yammacin Antarctica.    Rashin ƙanƙara a cikin Antarctic da gudummawar da yake bayarwa ga hawan teku maimakon ɗumamar Tekun Kudancin, wanda ya sha kashi 35-43% na yawan zafin da dukkan tekuna suka ɗauka tsakanin 1970 da 2017. 

Ra'ayoyin kankara-albedo suma suna da ƙaramin tasiri, amma har yanzu abin lura ne akan yanayin zafi na duniya. An kiyasta raguwar ƙanƙarar teku ta Arctic tsakanin 1979 da 2011 ta haifar da watts 0.21 a kowace murabba'in mita (W/ m2 ) na tilastawar radiation, wanda yayi daidai da kashi ɗaya cikin huɗu na ƙaruwar juriyar radiation daga CO  a cikin wannan lokacin. Idan aka kwatanta da ƙaruwar ƙaruwa a tilastawar radiation daga iskar gas mai dumama tun farkon juyin juya halin masana'antu, yayi daidai da kimanta tilastawar radiation daga nitrous oxide na 2019 (0.21 W/ m2 ), kusan rabin tilastawar radiation na 2019 daga methane (0.54 W/ m2 ) da 10% na ƙaruwar CO mai tarin  (2.16 W/ m2 ).  Tsakanin 1992 da 2015, wannan tasirin ya ɗan rage shi ta hanyar ƙaruwar murfin kankara a kusa da Antarctica, wanda ya haifar da sanyaya kusan 0.06 W/ m2 a kowace shekaru goma. Duk da haka, kankarar teku ta Antarctic ita ma ta fara raguwa daga baya, kuma haɗin gwiwar rawar da canje-canje a murfin kankara tsakanin 1992 da 2018 yayi daidai da kashi 10% na duk hayakin da ke fitar da hayakin gidan kore na ɗan adam. 

## Tasirin gaba

Tasirin ra'ayin kankara-albedo game da zafin jiki zai ƙara ƙaruwa a nan gaba yayin da ake hasashen raguwar ƙanƙarar tekun Arctic zai zama mafi bayyananne, tare da yuwuwar kusan cikar asarar murfin ruwan teku (faɗowa ƙasa da kilomita 1 miliyan 2 ) a ƙarshen lokacin rani na Arctic a cikin Satumba aƙalla sau ɗaya kafin 2050 a ƙarƙashin duk yanayin canjin yanayi a ƙarƙashin yanayin yanayin yanayi,  iskar gas. 

Tun watan Satumba shine ƙarshen lokacin rani na Arctic, yana kuma wakiltar nadir na murfin kankara a cikin yanayin yanzu, tare da tsarin farfadowa na shekara-shekara wanda ya fara a cikin hunturu Arctic . An yi la'akari da watan Satumba marasa ƙanƙara a jere a nan gaba, amma mitar su zai ƙaru tare da mafi girman matakan dumamar yanayi: wata takarda ta 2018 ta kiyasta cewa watan Satumba mara kankara zai faru sau ɗaya a cikin kowace shekara 40 a ƙarƙashin ɗumamar , amma sau ɗaya a kowace shekara 8 a ƙarƙashin  kuma sau ɗaya a kowace shekara 1.5 a ƙarƙashin  .  Wannan yana nufin cewa asarar ƙanƙara ta tekun Arctic a watan Satumba ko farkon lokacin rani ba zai yuwu ba, kuma a cikin al'amuran da dumamar yanayi ta fara juyawa, mitar sa na shekara-shekara zai fara raguwa. Don haka, ba a la'akari da ɗaya daga cikin abubuwan da ke cikin tsarin yanayi .  

Musamman ma, yayin da asarar murfin kankara na teku a watan Satumba zai zama wani taron tarihi tare da tasiri mai mahimmanci ga namun daji na Arctic kamar bears polar, tasirinsa akan ra'ayin kankara-albedo yana da iyakacin iyaka, kamar yadda yawan adadin makamashin hasken rana da Arctic ya samu a watan Satumba ya riga ya ragu sosai. A gefe guda, ko da ƙananan raguwa a cikin ƙanƙara na watan Yuni zai yi tasiri sosai, tun watan Yuni yana wakiltar kololuwar lokacin rani na Arctic da mafi tsananin canja wurin makamashin hasken rana. 

Samfuran CMIP5 sun yi kiyasin cewa jimillar asarar murfin kankarar tekun Arctic daga Yuni zuwa Satumba zai haɓaka yanayin zafi na duniya da , tare da kewayon 0.16-0.21&nbsp;°C, yayin da yanayin zafi na yanki zai karu da sama da  . Wannan kiyasin ya haɗa da ba wai kawai ra'ayin kankara-albedo da kanta ba, har ma da tasirinsa na biyu kamar tasirin irin wannan asarar kankara a kan raƙuman raƙuman raɗaɗi, canje-canje a cikin yawan tururin ruwa da ra'ayoyin girgije na yanki.  Tun da waɗannan ƙididdiga sun riga sun kasance ɓangare na kowane samfurin CMIP5 da CMIP6,  kuma an haɗa su a cikin hangen nesa na dumamar yanayi a ƙarƙashin kowace hanyar sauyin yanayi, kuma ba sa wakiltar tushen "ƙarin" dumi a saman abubuwan da suke da su.

### Tasirin dogon lokaci

Matsakaicin ɗumamar yanayi na iya hana ƙanƙarar tekun Arctic yin gyare-gyare a lokacin hunturu na Arctic. Ba kamar lokacin rani mara ƙanƙara ba, wannan lokacin sanyi na Arctic mara ƙanƙara na iya wakiltar wurin da ba za a iya juyawa ba. Zai fi dacewa ya faru a kusa da , kodayake yana iya faruwa a farkon  ko har zuwa  .   Yayin da ƙanƙaramar tekun Arctic zai ƙare har tsawon shekara guda, zai yi tasiri ne kawai akan ra'ayoyin kankara-albedo a cikin watannin da Arctic ke karɓar hasken rana - watau daga Maris zuwa Satumba. Bambanci tsakanin wannan jimillar asarar kankarar teku da jiharsa ta 1979 daidai yake da ton tiriliyan na CO  hayaki  - kusan kashi 40% na ton tiriliyan 2.39 na iskar hayaƙi tsakanin 1850 da 2019,  ko da yake kusan kashi ɗaya cikin huɗu na wannan tasirin ruwan ya riga ya faru tare da asarar kankara na yanzu. Dangantaka zuwa yanzu, lokacin sanyi mara kankara zai sami tasirin dumamar yanayi na , tare da dumamar yanayi tsakanin  da  . 

Ra'ayin Ice–albedo shima yana faruwa tare da sauran manyan kankara a saman duniya, kamar glaciers, Greenland ice sheet, West Antarctic da Gabashin Antarctic kankara . Duk da haka, ana sa ran narkawarsu mai girma zai ɗauki ƙarni ko ma millennia, kuma duk wani asara a cikin yanki tsakanin yanzu zuwa 2100 zai zama maras kyau. Don haka, ƙirar canjin yanayi ba sa haɗa su a cikin hasashe na canjin yanayi na ƙarni na 21: gwaje-gwajen da suka kwatanta bacewarsu sun nuna cewa jimlar asarar kankara ta Greenland ta ƙara  zuwa dumamar yanayi (tare da kewayon 0.04-0.06&nbsp;°C), yayin da asarar Fashin Kankara na Yammacin Antarctic ya ƙara  (0.04-0.06&nbsp;°C), kuma asarar dusar ƙanƙara ta ƙara  (0.07-0.09&nbsp;°C).  Waɗannan ƙididdiga sun ɗauka cewa dumamar yanayi tana tsayawa a matsakaicin  . Saboda haɓakar logarithmic na tasirin greenhouse,  Tasirin asarar kankara zai zama mafi girma a ƙaramin ɗumamar matakin 2020s, amma zai zama ƙasa idan ɗumamar ta ci gaba zuwa manyan matakai. 

Tun da tudun kankara na Gabashin Antarctic ba zai kasance cikin haɗarin bacewar gabaɗaya ba har sai ɗumamar yanayi mai girma na  ya kai, kuma tunda ana sa ran narkewar gabaɗaya zai ɗauki *aƙalla* shekaru 10,000 kafin ya ɓace gaba ɗaya har ma a lokacin, ba a yi la'akari da shi ba a irin waɗannan kimantawa. Idan hakan ya faru, ana sa ran matsakaicin tasiri akan zafin duniya zai kasance kusan  . Jimlar hasarar takardar kankara na Greenland zai ƙara yanayin zafi na yanki a cikin Arctic da tsakanin  da , yayin da yanayin zafi na yanki a Antarctica zai iya haura da  bayan asarar dusar ƙanƙara ta yammacin Antarctic da  bayan asarar dusar ƙanƙara ta Gabashin Antarctic. 

## Duniyar ƙwallon ƙanƙara

Ra'ayin ƙanƙara-albedo da ya gudu yana da mahimmanci ga samuwar Duniyar ƙwallon ƙanƙara - yanayin yanayi na yanayi mai sanyi sosai tare da cikakken murfin kankara. Shaidar Paleoclimate ta nuna cewa Duniyar ƙwallon ƙanƙara ta fara da glaciation na Sturtian kimanin shekaru miliyan 717 da suka wuce . Ya ci gaba har zuwa kusan 660 mya, amma wani lokacin Snowball ya biyo baya, Marinoan glaciation, kawai shekaru miliyan da yawa bayan haka, wanda ya kasance har zuwa 634 mya. 

Shaidar ilimin kasa ta nuna glaciers kusa da equator a lokacin, kuma samfura sun nuna ra'ayin kankara-albedo ya taka rawa.  Yayin da ƙanƙara ke tasowa, ƙarin hasken rana mai shigowa yana nunawa zuwa sararin samaniya, yana haifar da yanayin zafi a duniya. Ko Duniya ta kasance cikakkiyar ƙwallon dusar ƙanƙara (daskararre gaba ɗaya), ko kuma ƙwallon slush tare da ɗigon ruwa na bakin ciki har yanzu ana ta muhawara, amma tsarin amsa kankara-albedo yana da mahimmanci ga shari'o'in biyu. 

Bugu da ƙari, ƙarshen lokutan Duniya na ƙwallon ƙanƙara zai kuma haɗa da ra'ayoyin kankara-albedo. An ba da shawarar cewa lalatawar ta fara sau ɗaya isasshiyar ƙura daga zaizawar ƙasa ta taru a saman saman dusar ƙanƙara don rage albedo sosai. Wataƙila wannan ya fara ne a cikin yankuna na tsakiya, yayin da suke da sanyi fiye da wurare masu zafi, kuma suna samun ƙarancin hazo, don haka da an sami ƙarancin dusar ƙanƙara don binne tarin ƙura da dawo da albedo. Da zarar midlatitudes sun rasa isasshen ƙanƙara, da ba wai kawai ya taimaka wajen ƙara yawan zafin jiki na duniya ba, amma sake dawowar isostatic zai haifar da haɓakar volcanism don haka ginawa na CO , wanda ba zai yiwu ba a baya. 

## Tasirin duhun dusar ƙanƙara
Ana iya haɓaka tasirin ra'ayoyin ƙanƙara-albedo ta kasancewar ɓangarorin masu ɗaukar haske. Ana ajiye barbashi na iska a kan dusar ƙanƙara da saman kankara suna haifar da sakamako mai duhu, tare da yawan adadin barbashi yana haifar da raguwar albedo. Ƙananan albedo yana nufin cewa ƙarin hasken rana yana sha kuma yana ƙara narkewa.  Abubuwan da ke haifar da duhu sun haɗa da baƙin carbon da ƙurar ma'adinai .   Ci gaban ƙananan ƙwayoyin cuta, irin su dusar ƙanƙara a kan glaciers da kankara algae akan kankara na teku kuma na iya haifar da tasirin duhun dusar ƙanƙara.  Narkewar da algae ke haifarwa yana ƙaruwa da kasancewar ruwa mai ruwa a cikin dusar ƙanƙara da saman kankara, wanda hakan zai haifar da haɓakar yawan dusar ƙanƙara da algae na kankara kuma yana haifar da raguwa a cikin albedo, yana samar da ra'ayi mai kyau. 

## Ra'ayin Ice-albedo akan exoplanets
A duniya, yanayin yana da tasiri sosai ta hanyar hulɗa tare da hasken rana da matakan amsawa. Mutum na iya tsammanin exoplanets a kusa da sauran taurari kuma su fuskanci matakan amsawa ta hanyar hasken rana wanda ke shafar yanayin duniya. A cikin yin ƙirar yanayi na sauran taurari, bincike ya nuna cewa ra'ayin kankara-albedo ya fi karfi a kan taurari na duniya waɗanda ke kewaye da taurari (duba: rarrabuwa na taurari ) waɗanda ke da radiation kusa da ultraviolet . 

## Duba kuma

* Abubuwan da ke haifar da sauyin yanayi
* Hankalin yanayi
* Duhun Dusar ƙanƙara Project
* Polar gani-saw

## Manazarta