Rashin daidaituwa na Arctic dipole

Arctic dipole anomaly tsari ne na matsin lamba wanda ke nuna babban matsin lamba a yankunan arctic na Arewacin Amurka da ƙananan matsin lamba akan na Eurasia. Wannan tsari wani lokacin yana maye gurbin oscillation na Arctic da oscillation ta Arewacin Atlantic. An lura da shi a karo na farko a cikin shekaru goma na farko na 2000s kuma watakila yana da alaƙa da Canjin yanayi na baya-bayan nan. Arctic dipole yana barin karin iskõki na kudanci zuwa cikin Tekun Arctic wanda ke haifar da karin narkewar kankara. A lokacin rani na shekara ta 2007 ya taka muhimmiyar rawa a cikin rikodin ƙananan kankara na teku wanda aka rubuta a watan Satumba. Har ila yau, an haɗa dipole na Arctic da canje-canje a cikin tsarin yaduwar arctic wanda ke haifar da hunturu mai bushewa a Arewacin Turai, amma hunturu mai zafi a Kudancin Turai da hunturu masu sanyi a Gabashin Asiya, Turai da gabashin rabin Arewacin Amurka.

 Bayyanawa 
A cikin shekarun 1990s da farkon 2000s, yawancin nazarin fitar da kankara na teku na Arctic sun mayar da hankali kan Arctic da Arewacin Atlantic oscillations a matsayin manyan direbobi na fitarwa. Koyaya, wasu binciken, kamar waɗanda Watanabe da Hasumi suka yi  da Vinje,  sun ba da shawarar cewa oscillations na Arctic da Arewacin Atlantic ba koyaushe suke bayyana bambancin fitar da kankara na teku ba.

A shekara ta 2006, Bingyi Wu, Jia Wang, da John Walsh ne suka gabatar da anomaly na dipole na Arctic, ta amfani da bayanan NCEP / NCAR da suka shafi 1960-2002.  An bayyana shi azaman rarraba sararin samaniya na matsayi na biyu na yanayin aiki na orthogonal na matsakaicin matsakaicin matakin teku na kowane wata a arewacin 70 ° N, inda yanayin farko ya dace da oscillation na Arctic. Lokacin da aka ayyana don lokacin hunturu (Oktoba zuwa Maris), yanayin farko na gaba (Arctic oscillation) yana da asusun 61% na jimlar bambancin, yayin da yanayin na biyu na gaba (Anomaly na dipole na Arctic) yana da alhakin 13%. 

Duk da yake oscillation na Arctic yana da tsarin da ke tsakiya kuma yana rufe duk Arctic,  Arctic dipole anomaly yana da sanduna biyu na alamar da ba daidai ba: ɗaya a kan Canadian Arctic Archipelago da arewacin Greenland, ɗayan a kan Kara da Laptev seas.  Wannan tsarin dipole yana haifar da matsin lamba tare da isopleth sifili wanda aka tsara daga Bering Strait, a fadin Arctic zuwa tekun Greenland da Barents. A sakamakon haka, ana amfani da iskõki masu banƙyama a layi daya zuwa isopleth ko dai zuwa ga tekun Greenland da Barents (mahimmanci na dipole na Arctic) ko zuwa ga Bering Strait (mahimmancin dipole nactic). 

 Tasirin kankara na teku na Arctic 
Kodayake oscillation na Arctic yana da alhakin ƙarin bambancin matsakaicin matsin lamba a kan Arctic, iska mai iska wanda ke tasowa sakamakon tsarin sararin samaniya na anomaly na dipole Arctic ya sa shi babban direba na bambancin fitar da kankara na Arctic. A lokacin kyakkyawan lokaci na anomaly na dipole na Arctic, iskõki marasa kyau suna fitar da kankara na teku daga tsakiyar Arctic ta hanyar Fram Strait kuma zuwa cikin Tekun Greenland ta hanyar Transpolar Drift Stream. Sabanin haka, a lokacin mummunan lokaci, iskõki marasa kyau sun rage cire kankara ta teku ta hanyar Fram Strait. Wannan yana tallafawa Watanabe et al.,  da Wang et al.,  wanda ke nuna cewa fitar da kankara na teku yana ingantawa a lokacin kyakkyawan lokaci na anomaly na dipole Arctic, yayin da fitarwa ke raguwa a lokacin mummunan lokaci.

Koyaya, ba za a iya watsi da oscillation na Arctic ba yayin la'akari da fitar da kankara na teku daga Arctic. Da kansa, yaduwar da ke da alaƙa da wani lokaci mai kyau na Arctic Oscillation yana haifar da karuwa a fitar da kankara na teku, yayin da mummunan lokaci na oscillation na Arctic yana da alaƙa tare da rage fitar da kansar teku na Arctic.[1][2] Lokacin la'akari da fitar da kankara na teku dangane da anomaly na Arctic dipole, oscillation na Arctic yana ƙayyade alamar alamar matsakaicin matsakaicin matakin teku, yayin da anomaly din dipole na Arctic ke ƙayyade wurin da ya fi dacewa a matakin matsin teku (a kan tsibirin Arctic na Kanada da arewacin Greenland, ko a kan tekun Kara da Laptev). Sabili da haka, yayin da Arctic dipole anomaly ya ƙayyade ko za a inganta ko ƙuntata fitar da kankara ta teku gaba ɗaya, Arctic oscillation zai inganta ko rage tasirin Arctic dipoleanomaly.[3]

 Haɗin zuwa matsanancin lokacin rani na kankara 
An kuma ba da shawarar cewa Arctic dipole anomaly ya taka muhimmiyar rawa a cikin faruwar ƙananan kankara na teku da yawa waɗanda suka faru tun daga tsakiyar shekarun 1990, gami da mafi ƙanƙanta a cikin 2007. Wang da sauransu. ya ba da shawarar cewa ban da iskõki marasa kyau da ke fitar da kankara na teku daga cikin Arctic ta hanyar Fram Strait, kyakkyawan lokaci na anomalies na dipole na Arctic na iya ƙara yawan ruwan dumi daga Arewacin Pacific ta hanyar Bering Strait zuwa cikin Tekun Arctic. Ruwa mai zafi, ban da karuwar fitar da kankara na teku, na iya haifar da rage girman kankara na ruwa. Bugu da ƙari, ƙaddamarwa da kankara na teku daga lokutan hunturu da na rani na baya, da kuma yanayin da ya faru da yawa, yana taka rawa wajen ƙayyade mafi ƙarancin kankara na shekara guda.

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