Tsakiyar Miocene Mafi kyawun Yanayi

Tsakiyar Miocene Climatic Optimum (MMCO), wani lokacin ana kiranta Tsakiyar Tsakiyar Moso ta Miocene Thermal Maximum (MMTM),  wani lokaci ne na yanayi mai dumi a lokacin zamanin Miocene, musamman Matakai Burdigalian da Langhian. 

 Tsawon lokaci 
Dangane da saukin kamuwa da magnetic na jerin sassan Miocene a cikin sashin Huatugou a cikin Qaidam Basin, MMCO ya kasance daga 17.5 zuwa 14.5 Ma; duwatsun da aka ajiye a wannan lokacin suna da saukin magnetic saboda samar da superparamagnetic da yanki ɗaya Magnetite a cikin yanayin zafi da zafi a lokacin da ke bayyana MMCO.

Kimanin da aka samo daga Mg / Ca palaeothermometry a cikin benthic foraminifer Oridorsalis umbonatus ya nuna farkon MMCO ya faru a 16.9 Ma, mafi girman zafi a 15.3 Ma, da ƙarshen MMCO a 13.8 Ma. 

 Yanayi 
Matsakaicin yanayin zafi na duniya a lokacin MMCO ya kasance kusan 18.4 ° C, game da 3 ° C mai dumi fiye da yau kuma 4 ° C mai zafi fiye da preindustrial. Yankin latitudinal na yanayin zafi ya karu sosai. Yanayin yanayi na latitudinal ya kasance game da 0.3 ° C a kowace digiri na latitude. A lokacin orbital eccentricity maxima, wanda ya dace da matakai masu dumi, lysocline na teku ya yi [bayyanawa da ake buƙata] da kusan mita 500.     

Arctic ba shi da kankara kuma yana da dumi don karɓar bakuncin gandun daji na dindindin a duk faɗin girmansa. Iceland tana da yanayi mai zafi da kuma yanayin zafi.Steinthorsdottir, M.; Coxall, H. K.; de Boer, A. M.; Huber, M.; Barbolini, N.; Bradshaw, C. D.; Burls, N. J.; Feakins, S. J.; Gasson, E.; Henderiks, J.; Holbourn, A. E.; Kiel, S.; Kohn, M. J.; Knorr, G.; Kürschner, W. M. (23 December 2020). "The Miocene: The Future of the Past". Paleoceanography and Paleoclimatology. 36 (4). doi:10.1029/2020PA004037. hdl:10852/85961. ISSN 2572-4517. Retrieved 24 December 2023 – via Wiley Online Library.

Matsakaicin zafin jiki na shekara-shekara (MAT) na Ƙasar Ingila ya kasance 16.9 ° C. A Tsakiyar Turai, mafi ƙarancin zafin watanni masu sanyi (mCMT) ya kasance aƙalla 8.0 °C kuma mafi ƙarancen zafin watanni mai zafi (mWMT) ya kasance kusan 18.3 °C, tare da MAT gaba ɗaya ba mai sanyi fiye da 17.4 °C ba. Yankin ruwan sama na shekara-shekara na Tsakiyar Turai ya kasance 1050-1600 mm, bisa ga bayanai daga Hevlín Quarry a Jamhuriyar Czech. Bayanan yanayi daga Poland da Bulgaria sun ba da shawarar ƙarancin yanayin zafi a Turai a lokacin MMCO .  Kyakkyawan gandun daji masu zafi sun rufe yawancin Faransa, Switzerland, da arewacin Jamus, yayin da kudanci da tsakiyar Spain sun bushe kuma suna dauke da wuraren budewa. A cikin Arewacin Alpine Foreland Basin (NAFB), keken ruwa ya kara karfi a lokacin MMCO. Garin Austrian na Stetten yana da matsakaicin zafin hunturu na 9.6-13.3 °C da matsakaitan zafin bazara na 24.7-27.9 °C, ya bambanta da -1.4 °C da 19.9 °C bi da bi a halin yanzu; yawan ruwan sama a wannan shafin ya kasance 9-24 mm a cikin hunturu da 204-236 mm a lokacin rani. Abin mamaki, ruwan kasa na Vienna Basin yana nuna alamar sanyaya a lokacin MMCO.          

Yanayin bazara na Arewacin Hemisphere na Yankin Intertropical Convergence Zone (ITCZ) ya koma arewa; saboda ITCZ shine yankin mafi yawan ruwan sama, ruwan sama da Gabashin Asiya Summer Monsoon (EASM) ya kawo ya karu a kudancin China yayin da yake raguwa a kan Indochina.  Filayen Tibet ya fi ruwan sama kuma ya fi zafi.Guan, Chong; Chang, Hong; Yan, Maodu; Li, Leyi; Xia, Mengmeng; Zan, Jinbo; Liu, Shuangchi (15 October 2019). "Rock magnetic constraints for the Mid-Miocene Climatic Optimum from a high-resolution sedimentary sequence of the northwestern Qaidam Basin, NE Tibetan Plateau". Palaeogeography, Palaeoclimatology, Palaeoecology. 532 109263. Bibcode:2019PPP...53209263G. doi:10.1016/j.palaeo.2019.109263. ISSN 0031-0182. S2CID 198407262. Retrieved 10 January 2024 – via Elsevier Science Direct.

Gabaɗaya, Yammacin Arewacin Amurka a arewacin 40 ° N ya fi ruwa fiye da kudancin 40 ° C. Yankin Pacific Northwest ya sami karuwar hazo a lokacin MMCO a kusa da 15.1 Ma. Sabanin haka, yankin Mojave na yammacin Arewacin Amurka ya nuna yanayin bushewa. Tare da shelf na New Jersey, MMCO bai haifar da wani siginar yanayi ba dangane da lokacin da ya gabata ko daga baya na Miocene; yanayin zafi a nan na iya kasancewa ƙasa ta hanyar hauhawar Dutsen Appalachian.

 Dalilan da suka haifar 
Rashin zafi na duniya na MMCO ya samo asali ne daga hauhawar carbon dioxide na yanayi dangane da sauran Neogene.

Ragewar albedo daga raguwar yankin duniya da hamada ta rufe da fadada gandun daji wani muhimmin ra'ayi ne mai kyau wanda ke inganta dumi na MMCO.

 Manazarta 
Rukuni:Shafuka masu fassarorin da ba'a duba ba