Model–proxy comparison for overshoot phenomenon of Atlantic thermohaline circulation at Bφlling–Allerφd  

作　　者：Jun Cheng Zhengyu Liu Feng He Bette Otto-Bliesner Esther Brady Jean Lynch-Stieglitz 

机构地区：[1]Polar Climate System and Global Change Laboratory and Earth System Modeling Center (ESMC), Nanjing International Academy of Meteorological Sciences (NIAMS), Nanjing University of Information Science and Technology [2]Department of Atmospheric and Oceanic Sciences, Center for Climatic Research, University of Wisconsin-Madison [3]LaCOAS/Department of Atmospheric and Oceanic Sciences,Peking University [4]Climate and Global Dynamics Division, National Center for Atmospheric Research [5]School of Earth and Atmospheric Sciences, Georgia Institute of Technology

出　　处：《Chinese Science Bulletin》2014年第33期4510-4515,共6页

基　　金：supported by National Natural Science Foundation of China(41206024,41130105);the National Science Foundation and Department of Energy of USA;Earth System Modeling Center(ESMC)contribution number ESMC-007

摘　　要：The overshoot phenomenon of the Atlantic thermohaline circulation(THC) is a transient climate response to meltwater forcing and could induce intense climate change by increasing the magnitudes of Atlantic THC changes at the end of meltwater discharges. This phenomenon was formally presented with the successfully simulated Bφlling–Allerφd(BA) event in the first transient simulation of the last deglaciation with fully coupled model NCAR-CCSM3(TraCE-21K). Currently, not all proxy records of Atlantic THC support the occurrence of the THC overshoot at BA. Commonly used THC proxy from Bermuda Rise(GGC5) does not exhibit THC overshoot at BA but other proxies such as TTR-451 at Eirik Drift do. How to interpret this regional discrepancy of proxy records is a key question for the validation of the Atlantic THC overshoot at BA. Here, we show that the vigor of deep circulation varies regionally during the Atlantic THC overshoot at BA in TraCE-21 K simulation, and this regional discrepancy in the simulation is consistent with that in the marine sediment records in North Atlantic. The consistent model–proxy evidence supports the occurrence of Atlantic THC overshoot at BA.The overshoot phenomenon of the Atlantic thermohaline circulation （THC） is a transient climate response to meltwater forcing and could induce intense climate change by increasing the magnitudes of Atlantic THC changes at the end of meltwater discharges. This phenomenon was formally presented with the successfully simulated Bolling-Allerod （BA） event in the first transient simulation of the last deglaciation with fully coupled model NCAR-CCSM3 （TraCE-21K）. Currently, not all proxy records of Atlantic THC support the occurrence of the THC overshoot at BA. Commonly used THC proxy from Bermuda Rise （GGC5） does not exhibit THC overshoot at BA but other proxies such as TTR-451 at Eirik Drift do. How to interpret this regional discrepancy of proxy records is a key question for the validation of the Atlantic THC overshoot at BA. Here, we show that the vigor of deep circulation varies regionally during the Atlantic THC overshoot at BA in TraCE-21K simulation, and this regional discrepancy in the simulation is consistent with that in the marine sediment records in North Atlantic. The consistent model-proxy evidence supports the occurrence of Atlantic THC overshoot at BA.

关 键 词：北大西洋 过冲现象 温盐环流 代理 模型 模拟过程 THC 气候变化 

分 类 号：P731.2[天文地球—海洋科学]