全新世北大西洋海面温度变化趋势：观测-模拟对比研究  

CHANGING TRENDS OF SEA SURFACE TEMPERATURES IN THE NORTH ATLANTIC DURING THE HOLOCENE： A STUDY OF MODEL-DATA COMPARISON

作　　者：焦腾腾 李佳瑞[1] 陈婕[1] 张肖剑[1] 靳立亚[1] 

机构地区：[1]兰州大学资源环境学院,西部环境教育部重点实验室,兰州730000

出　　处：《第四纪研究》2016年第3期747-757,共11页Quaternary Sciences

基　　金：国家自然科学基金项目（批准号：41275071和41130102）和兰州大学中央高校基本科研业务费专项资金（批准号：lzujbky-2015-218）共同资助

摘　　要：摘要本文利用KielClimateModel（KCM模式）对全新世气候的模拟结果及其与北大西洋表层海水温度（sea surface temperature，简称SST）重建记录的对比，探讨了全新世北大西洋SST的变化趋势。浮游植物的长链烯酮不饱和度显示低纬北大西洋SST在全新世期间有升高趋势，而在中纬和高纬地区表现为显著的下降趋势，尤其是在中纬北大西洋西部，最大降温幅度达到7．9℃／9．5ka。浮游有孔虫壳体的镁钙比值显示中纬北大西洋东部及高纬北大西洋有增温趋势，而在中纬北大西洋西部及低纬北大西洋则有降温趋势，但变化幅度均比较小，绝大部分在2℃／9．5ka以下。气候模拟结果显示全新世北大西洋SST变化呈现明显的“三核型”经向模态，在冬春季以增温为主，降温限于拉布拉多海东南部的北大西洋海域；在夏秋季以降温为主，增温限于低纬和高纬北大西洋海域。模拟与重建的对比显示，中纬和低纬北大西洋的长链烯酮不饱和度指标以及低纬西部的镁钙比指标可能反映夏秋季海温，中纬北大西洋东部的镁钙比指标可能反映冬春季海温，而中纬西部和高纬的镁钙比指标可能对4个季节的SST都有所反映。Changing trends of the sea surface temperatures （SSTs） in the North Atlantic were analyzed in this study through comparing proxy records and climatic simulation results. Paleo-SST proxy records, including 27 alkenone records and 12 Mg/Ca records, are from the extended global database for alkenone-derived Holocene SST records （GHOST database）. Climatic simulation results are from a long-term transient simulation performed with a coupled atmosphere-ocean-sea ice general circulation model, the Kiel Climate Model （KCM） , forced by the Earth＇s orbital variations for the last 9500 years. Other forcing factors such as Greenhouse gas and continental ice sheets have been neglected. Alkenone-derived SSTs exhibit a warming trend in the low-latitude North Atlantic （0-15~N） and a cooling trend in the middle-and high-latitude North Atlantic during the Holocene. The greatest variability in SSTs is seen in the middle-latitude western North Atlantic, with a trend reaching -7.9~C/9.5ka. Mg/Ca-based SSTs show distinct trends from alkenone records with an increasing trend over the middle-latitude eastern and high-latitude North Atlantic and a decreasing trend over middle-latitude western and low-latitude North Atlantic. SST trends derived from Mg/Ca records are much smaller than that from alkenone records. Model results suggest a longitudinal tripole pattern in the linear trends of North Atlantic SSTs during the Holocene for all four seasons, with a center of decreasing trend sandwiched between two centers of increasing trend. North Atlantic SSTs were dominated by a warming trend in winter and spring and a cooling trend in summer and autumn. The cooling trend in winter and spring is distributed only over the southwest of the Labrador Sea, while the warming trend in summer and autumn is mainly distributed in the low-and high-latitude North Atlantic. Model-data comparisons suggest that alkenone records may reflect summer and autumn SSTs in the low-and middle-latitude North Atlantic. Mg/Ca records may represent summer

关 键 词：全新世 北大西洋 海温 代用记录 气候模拟 季节信号 

分 类 号：P725.1[天文地球—海洋科学] P532