Summer Temperature over the Tibetan Plateau Modulated by Atlantic Multidecadal Variability

• Published in: Journal of Climate
• Main Authors: Shi, Chunming, Sun, Cheng, Wu, Guocan, Wu, Xiuchen, Chen, Deliang, Masson-Delmotte, Valérie, Li, Jianping, Xue, Jiaqing, Li, Zongshan, Ji, Duoying, Zhang, Jing, Fan, Zexin, Shen, Miaogen, Shu, Lifu, Ciais, Philippe
• Other Authors: Capital Normal University Beijing, University of Gothenburg (GU), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of Chinese Academy of Sciences Beijing (UCAS), Chinese Academy of Tropical Agricultural Sciences (CATAS), Institute of Tibetan Plateau Research, Chinese Academy of Sciences Beijing (CAS), Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, State Forestry Administration, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; North Atlantic; permafrost
• Online Access: https://hal.archives-ouvertes.fr/hal-02899707; https://hal.archives-ouvertes.fr/hal-02899707/document; https://hal.archives-ouvertes.fr/hal-02899707/file/%5B15200442%20-%20Journal%20of%20Climate%5D%20Summer%20Temperature%20over%20the%20Tibetan%20Plateau%20Modulated%20by%20Atlantic%20Multidecadal%20Variability.pdf; https://doi.org/10.1175/JCLI-D-17-0858.1

International audience Rapid warming has led to an aggregated environmental degradation over the Tibetan Plateau (TP) in the last few decades, including accelerated glacier retreat, early snowmelt, permafrost degradation, and forest fire occurrence. Attribution of this warming in recent decades has mainly been focused on anthropogenic forcing. Yet, linkages to the Atlantic multidecadal variability (AMV), an essential part of the climate system causing decadal to centennial fluctuations of temperature, remains poorly understood for the TP, especially at long time scales. Using well-replicated tree-ring width records, we reconstructed 358 years of summer minimum temperature (MinT) of the whole TP. This reconstruction matches the recent warming signal recorded since the 1980s, and captures 63% of the variance in 1950–2005 instrumental records. A teleconnection from the North Atlantic to the TP is further identified based in observations and simulations with an atmospheric general circulation model (AGCM). We propose that half of the multidecadal variability of TP summer MinT can be explained by the AMV over the past three and a half centuries. Both observations and AGCM simulations indicate that the AMV warm phase induces a zonal dipole response in sea level pressure across the Atlantic–Eurasia region, with anomalously high surface pressure and corresponding downward atmospheric motion over the TP. We propose that the descending motion during warm AMV phases causes negative rainfall and positive temperature anomalies over the TP. Our findings highlight that the AMV plays a role in the multidecadal temperature variability over the TP.