Gidan kankara na Arctic

Kunshin kankara na Arctic shine murfin kankara na Tekun Arctic da kuma kusancinsa. Fakitin kankara na Arctic yana jure yanayin yanayi na yau da kullun wanda kankara ke narkewa a bazara da bazara, ya kai mafi ƙarancin kusan tsakiyar Satumba, sannan yana ƙaruwa a lokacin kaka da hunturu. Murfin kankara na bazara a cikin Arctic shine kusan kashi 50% na murfin hunturu.[1] Wasu daga cikin kankara suna rayuwa daga shekara ɗaya zuwa gaba. A halin yanzu, kashi 28% na ƙanƙaramar tekun Arctic ƙanƙara ce ta shekaru da yawa, [2] ta fi ƙanƙara mai kauri: har zuwa mita 3-4 (9.8-13.1 ft) mai kauri sama da manyan wurare, tare da kauri har zuwa mita 20 (65.6 ft). Bayan zagayowar yanayi na yau da kullun an sami ci gaba na raguwar ƙanƙara ta teku a cikin Arctic a cikin 'yan shekarun nan kuma.

 Muhimmancin yanayi 

 Sakamakon ma'aunin makamashi 
Gishiri na teku yana da muhimmiyar tasiri a kan ma'aunin zafi na tekun polar, tunda yana rufe teku mai dumi (da ɗan gajeren lokaci) daga iska mai sanyi a sama, don haka rage asarar zafi daga tekuna. Gishiri na teku yana nuna Hasken rana sosai, yana nuna kusan 60% na hasken rana mai shigowa lokacin da ba shi da komai kuma kusan 80% lokacin da aka rufe shi da dusar ƙanƙara. Wannan ya faru ne saboda ra'ayi da aka sani da tasirin albedo. Wannan ya fi girma fiye da hasken teku (kimanin 10%) kuma ta haka ne kankara kuma yana shafar shawo kan hasken rana a farfajiyar.

 Tasirin ruwa 
Tsarin kankara na teku kuma muhimmiyar tushe ce ta "ruwa mai zurfi". Lokacin da ruwan teku ya daskare ya bar mafi yawan gishiri a baya. Ragowar ruwa, wanda aka yi da yawa ta hanyar ƙarin gishiri, yana nutsewa kuma yana samar da ruwa mai yawa kamar Arewacin Atlantic Deep Water. Wannan samar da ruwa mai yawa yana da mahimmanci wajen kula da yaduwar thermohaline, kuma daidaitattun wakilcin waɗannan matakai suna da mahimmanci a cikin ƙirar yanayi.

 Odden 
A cikin Arctic, wani muhimmin yanki inda kankara ta pancake ta samar da nau'in kankara mafi rinjaye a duk yankin shine abin da ake kira harshen kankara na Odden a cikin Tekun Greenland. Odden (kalmar ita ce Norwegian don tudun) tana girma zuwa gabas daga babban gefen kankara na Gabashin Greenland a kusa da 72-74 ° N a lokacin hunturu saboda kasancewar ruwan sanyi sosai a cikin Jan Mayen Current, wanda ke karkatar da wasu ruwa zuwa gabas zuwa Gabashin Greenlands Current a wannan latitude. Yawancin tsoffin kankara suna ci gaba da kudu, iska ce ke fitar da su, don haka ana nuna ruwan sanyi wanda sabon kankara ke kama da frazil da pancake a cikin teku mai tsanani.

 Girman da girman kankara na teku da abubuwan da ke faruwa 

Rubuce-rubucen kankara ta teku Arctic daga Cibiyar Hadley ta Burtaniya don Tsinkaya da Bincike sun koma zuwa farkon karni na 20, kodayake ingancin bayanan kafin 1950 yana da muhawara. Ma'aunin da za a iya dogara da shi na gefen kankara na teku ya fara ne a cikin zamanin tauraron dan adam. Daga ƙarshen 1970s, Scanning Multichannel Microwave Radiometer (SMMR) a kan Seasat (1978) da Nimbus 7 (1978-87) tauraron dan adam sun ba da bayanin da ya kasance mai zaman kansa daga hasken rana ko yanayin yanayi. Matsakaicin da daidaito na ma'aunin microwave ya inganta tare da ƙaddamar da DMSP F8 Special Sensor Microwave / Image (SSMI) a cikin 1987. Dukkanin Yankin kankara na teku da girmansa an kiyasta su, tare da ƙarshen ya fi girma, kamar yadda aka bayyana shi a matsayin yankin teku tare da akalla 15% kankara na ruwa.

Binciken samfurin shekaru 52 daga 1947 zuwa 1999 ya sami wani muhimmin yanayin kididdiga a cikin ƙarancin kankara na Arctic na -3% a kowace shekara goma; raba wannan zuwa iska da zafin jiki ya tilasta abubuwan da aka tilasta ya nuna cewa duk abin da ya haifar da ƙarfin zafin jiki. Wani lissafi na kwamfuta, wanda aka warware lokaci na girman kankara na teku, wanda ya dace da ma'auni daban-daban, ya bayyana cewa saka idanu kan girman kankara ya fi mahimmanci don kimanta asarar kankara na ruwa fiye da la'akari da yanki mai tsabta.Zhang, Jinlun and D.A. Rothrock: Modeling global sea ice with a thickness and enthalpy distribution model in generalized curvilinear coordinates, Mon. Wea. Rev. 131(5), 681–697, 2003. 

Matsayin ƙanƙara daga 1979 zuwa 2002 sun kasance raguwar ƙanƙarar tekun Arctic mai mahimmanci -2.5% ± 0.9% a kowace shekara goma a cikin waɗannan shekaru 23.  Samfuran yanayi sun kwaikwayi wannan yanayin a cikin 2002.  Mafi ƙarancin yanayin ƙanƙara na Satumba na 1979-2011 ya ƙi da 12.0% a cikin shekaru goma a cikin shekaru 32.  A cikin 2007, mafi ƙaranci ya faɗi da fiye da murabba'in kilomita miliyan, raguwa mafi girma tun lokacin da aka samu cikakkun bayanan tauraron dan adam, zuwa    . Wani sabon bincike ya nuna kankarar Tekun Arctic yana narkewa da sauri fiye da yadda kowane nau'in na'ura mai kwakwalwa 18 ya yi amfani da shi wajen shirya kimarsa na 2007.  A cikin 2012, sabon rikodin ƙarancin kusan    ya isa.  

A cikin ma'auni na duka, girman kankara ta teku ya dogara da kaurin kankara da kuma girman yankin. Duk da yake zamanin tauraron dan adam ya ba da damar inganta ma'auni na abubuwan da ke faruwa a cikin yanki, daidaitattun ma'aunin kaurin kankara ya kasance ƙalubale. "Duk da haka, matsanancin asarar murfin kankara na wannan lokacin rani da kuma jinkirin farawa na daskarewa yana da ƙarancin ƙanƙara fiye da yadda aka saba a duk lokacin kaka da hunturu, kuma kankara da ke girma zai iya zama mai laushi". Kamar yadda yawancin kankara na teku ya fi ƙanƙanta a shekara ta farko babban tasirin guguwa yana da shi akan kwanciyar hankali tare da rikice-rikice wanda ya haifar da manyan Guguwa ta extratropical wanda ke haifar da raguwar kankara na ruwa.

 Manazarta