Yanayin Alpine
Sauyin yanayi mai tsayi shine yanayi na yau da kullum don hawa sama da layin bishiyar,inda bishiyoyi suka kasa girma saboda sanyi. Ana kuma kiran wannan yanayi da yanayin tsaunuka ko yanayin tsaunuka.
Ma'anarsa[gyara sashe | gyara masomin]
Akwai ma'anoni da yawa na yanayi mai tsayi.
Acikin rarrabuwar yanayi na Köppen,yanayin tsaunuka da tsaunuka suna cikin rukuni na E,tare da yanayin polar,inda babu wata yana da ma'anar zafin jiki sama da 10 °C (50 °F).
Dangane da tsarin yankin rayuwa na Holdridge,akwai yanayin tsaunuka guda biyu waɗanda ke hana haɓɓakar bishiyoyi :
a) yanayi mai tsayi,wanda ke faruwa a lokacin da ma'anar yanayin yanayin yanayi ya kasance tsakanin 1.5 and 3 °C (34.7 and 37.4 °F). Yanayin tsayin daka acikin tsarin Holdridge yayi kusan dai-dai da yanayin tundra mafi zafi (ET) acikin tsarin Köppen.
b) yanayin alvar, yanayin tsaunuka mafi sanyi tun lokacin da yanayin zafin jiki ke tsakanin 0 °C da 1.5 °C (biotemperature bazai taɓa zama ƙasa da 0 ba °C). Yayi dai-dai fiye ko žasa da yanayin tundra mafi sanyi da kuma yanayin ƙanƙara(EF) kuma.
Holdrige yayi tunanin cewa shuke-shuken kayan aikin farko sun daina aiki tare da tsire-tsire suna barci a yanayin zafi ƙasa 0 °C (32 °F) da sama da 30 °C (86 °F).[1] Saboda haka, ya ayyana biotemperature a matsayin ma'anar duk yanayin zafi amma tare da duk yanayin da ke ƙasa da daskarewa kuma sama da 30. °C ya dai-daita zuwa 0 °C; wato jimlar yanayin zafi da ba a daidaita ba an raba ta da adadin duk yanayin zafi(ciki har da waɗanda aka dai-daita da waɗanda ba a dai-daita su ba).
Bambance-bambancen yanayi mai tsayi a duk shekara ya dogara da latitude na wurin.Don wurare masu zafi na teku, irin su koli na Mauna Loa, zafin jiki yana da tsayi a cikin shekara.Don wuraren tsakiyar latitude, irin su Dutsen Washington a New Hampshire, zafin jiki yana bambanta lokaci-lokaci, amma baya samun ɗumi sosai.
Dalili[gyara sashe | gyara masomin]
Bayanin yanayi shine sakamakon hulɗa tsakanin radiation da convection. Hasken rana acikin bakan da ake iya gani yana bugi ƙasa yana ɗumama shi. Sannan ƙasa tana ɗumama iska a saman. Idan radiation ita ce hanya daya tilo don canja wurin zafi daga ƙasa zulwa sararin samaniya, tasirin iskar gas a cikin yanayi zai kiyaye ƙasa a kusan 333 K (60 °C; 140 °F), kuma zafin jiki zai lalace sosai tare da tsayi.
Duk da haka, lokacin da iska ya yi zafi,yakan yi girma, wanda ya rage yawan nauyinsa.Don haka,iska mai zafi tana ƙoƙarin tashi da canja zafi zuwa sama. Wannan shine tsarin convection. Convection yana zuwa ga dai-daito lokacin da gunkin iska a wani tsayin da aka ba shi yana da yawa iri ɗaya da kewayensa.Iskar zafi ce mara kyau,don haka gunkin iska zai tashi ya faɗi ba tare da musayar zafi ba. Ansan wannan a matsayin tsarin adiabatic,wanda ke da yanayin yanayin matsa lamba-zazzabi.Yayin da matsa lamba ya ragu,zafin jiki yana raguwa.Adadin raguwar zafin jiki tare da haɓɓaka ana san shi da ƙimar lapse adiabatic,wanda shine kusan 9.8 °C a kowace kilomita (ko 5.4 °F akan 1000 ƙafa) na tsayi.
Kasancewar ruwa a cikin yanayi yana rikitar da tsarin convection. Turin ruwa yana ƙunshe da latent zafi na vaporization . Yayin da iska ke tashi da sanyi, a ƙarshe ya zama cikakke kuma ba zai iya ɗaukar yawan tururin ruwa ba. Turin ruwa yana takushe (farar gajimare ), kuma yana fitar da zafi, wanda ke canza adadin lapse daga busasshen adadin adiabatic busasshen zuwa madaidaicin ƙarancin adiabatic (5.5). °C a kowace kilomita ko 3 °F akan 1000 ƙafa). Matsakaicin raguwa na ainihi, wanda ake kira ƙimar ƙarancin muhalli, ba koyaushe ba ne (zai iya canzawa cikin yini ko yanayi da kuma yanki), amma ƙimar al'ada ita ce 5.5. °C da 1,000 m (3.57 °F akan 1,000 ft). Don haka, motsi sama da 100 metres (330 ft) akan dutse yayi daidai da motsi 80 kilomita (50 mil ko 0.75 ° na latitude ) zuwa sandar sanda. Wannan dangantakar kusan kusan ce kawai, duk da haka, tunda abubuwan gida, kamar kusancin tekuna, na iya canza yanayin sosai. Yayin da tsayin daka ya karu, babban nau'i na hazo ya zama dusar ƙanƙara kuma iskoki suna karuwa. Zazzabi yana ci gaba da faɗuwa har zuwa lokacin da aka rufe, a 11,000 metres (36,000 ft), inda ba ya kara raguwa. Wannan ya fi koli mafi girma .
Rarrabawa[gyara sashe | gyara masomin]
Ko da yake wannan rarrabuwar yanayi ya ƙunshi ɗan ƙaramin yanki na saman duniya, yanayin tsaunukan tsaunuka suna yaduwa sosai. Sun kasance a cikin Himalayas, Tibet Plateau, Gansu, Qinghai, Alps, Pyrenees, Cantabrian tsaunin da Saliyo Nevada a cikin Eurasia, Andes a Kudancin Amirka, Saliyo Nevada, Cascade Mountains, Dutsen Rocky, da arewacin Appalachian Mountains (Adirondacks da White Mountains), da kuma Trans-Mexican volcanic bel a Arewacin Amirka, Kudancin Alps a New Zealand, dusar ƙanƙara a Ostiraliya, manyan tuddai a cikin tsaunukan Atlas da Gabashin tsaunukan Afirka, da tsakiyar tsakiyar Afirka. sassa na Borneo da New Guinea da koli na Dutsen Pico a cikin Tekun Atlantika da Mauna Loa a cikin Pacific .
Mafi ƙanƙancin tsayin yanayin tsaunuka ya bambanta sosai ta wurin latitude. Idan an ayyana yanayin yanayi mai tsayi ta layin bishiyar, to yana faruwa a ƙasan 650 metres (2,130 ft) a 68°N a Sweden, [2] yayin da yake kan Dutsen Kilimanjaro a Tanzaniya, layin bishiyar yana kan 3,950 metres (12,960 ft) . [2]
Duba kuma[gyara sashe | gyara masomin]
- Alpine shuka
- Yanayi na Alps
- Jerin wuraren yanayi mai tsayi