Lokacin hunturu na dutsen wuta
 Lokacin hunturu na dutsen wuta | |
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| Bayanai | |
| Ƙaramin ɓangare na |
volcanic phenomenon (en)  |
Lokacin hunturu na dutsen wuta shine raguwar yanayin zafi na Duniya wanda ya haifar da ɗigon sulfuric acid wanda ke rufe Rana da kuma tada albedo na Duniya (ƙara hasken rana) bayan babban, mai wadataccen sulfur, musamman fashewar dutsen wuta. Tasirin yanayi ya dogara da adadin allurar H2 a cikin stratosphere inda suke amsawa tare da OH da H2O don samar da H2SO4 a kan lokaci na mako, kuma sakamakon H2SO9 aerosols yana samar da tasirin radiative. Aerosols na stratospheric na volcanic suna sanyaya farfajiyar ta hanyar nuna hasken rana da dumi stratosphere ta hanyar shan radiation na duniya na shekaru da yawa. Bugu da ƙari, yanayin sanyaya na iya kara fadadawa ta hanyar hanyoyin amsawar yanayi-ice-ocean. Wadannan ra'ayoyin zasu iya ci gaba da kula da yanayin sanyi na dogon lokaci bayan da aerosols na dutsen wuta suka ɓace.
Tsarin jiki
[gyara sashe | gyara masomin]Wani fashewar dutsen mai fashewa ya saki kayan a cikin nau'in toka da iskar gas a cikin yanayi. Duk da yake mafi yawan ya zauna a ƙasa a cikin 'yan makonni bayan fashewar, yana tasiri ne kawai a yankin na ɗan gajeren lokaci, SO2 da aka fitar na iya haifar da kafa H2SO4 a cikin stratosphere.[1][2] Wadannan aerosols na iya kewaye da hemisphere na tushen fashewa a cikin makonni kuma suna ci gaba tare da lokacin lalacewa na e-folding na kimanin shekara guda. A sakamakon haka, suna da tasirin radiative wanda zai iya dadewa na shekaru da yawa.[1]
Rarraba girgije mai tsauri na gaba a cikin stratosphere da tasirinsa akan yanayi yana da tasiri mai ƙarfi da dalilai da yawa, gami da lokacin fashewa, [3] latitude na dutsen mai aman wuta, [4] da tsayin allura. [2] Idan tsayin allura na SO 2 ya kasance a tsare ga troposphere, sakamakon H 2 SO 4 aerosols yana da lokacin zama na 'yan kwanaki kawai saboda ingantaccen cirewa ta hanyar hazo. [2] Rayuwar H 2 SO 4 aerosols da ke haifar da fashewar yanayi ya fi guntu idan aka kwatanta da wadanda ke fitowa daga wurare masu zafi, saboda hanyar sufuri mai tsawo daga wurare masu zafi don cirewa a cikin tsakiyar ko babban latitude tropopause, amma ƙananan wurare masu zafi suna ƙarfafa tasirin yanayi na hemispheric ta hanyar taƙaita amisphere zuwa guda ɗaya. [4] Injections a cikin hunturu kuma ba su da ƙarfi sosai fiye da alluran lokacin bazara don fashewar dutsen mai tsayi mai tsayi, lokacin da aka haɓaka kawar da iska mai iska a cikin yankuna na polar. [3]
Sulfate aerosol yana hulɗa sosai tare da Hasken rana ta hanyar warwatsewa, yana haifar da abubuwan gani na yanayi a cikin stratosphere. Wadannan abubuwan da suka faru sun hada da Hasken rana, coronae ko zoben Bishop, launi na musamman, da duhu na duhu.[1] Tarihin tarihi da suka rubuta waɗannan abubuwan da suka faru a sararin samaniya alamun hunturu ne na dutsen wuta kuma sun koma lokutan da suka gabata kambin zamanin yau da kullun[5]
Binciken zafin jiki na ƙasa bayan fashewar tarihi ya nuna cewa babu wata alaƙa tsakanin girman fashewa, kamar yadda aka wakilta ta VEI ko girman fashewar, da tsananin sanyaya yanayi. Wannan shi ne saboda girman fashewa ba ya da alaƙa da adadin SO2 da aka fitar.[6]