东海内陆架夏季台风与冬季寒潮沉积动力过程的差异——基于现场观测的认识  

Differences in sedimentary dynamic processes between summer typhoons and winter cold waves on the inner shelf of the East China Sea:Insights from in-situ observations

作　　者：卢健[1] 姜静波[2] 李安春[1] 马小川[1] LU Jian;JIANG Jingbo;LI Anchun;MA Xiaochuan(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences,Qingdao,266071,China)

机构地区：[1]中国科学院海洋研究所海洋地质与环境重点实验室,青岛266071 [2]中国科学院海洋研究所海洋环流与波动重点实验室,青岛266071

出　　处：《海洋地质与第四纪地质》2023年第5期96-105,共10页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目“近五千年来西北太平洋台风活动在东海内陆架的沉积记录研究”(42276052);山东省自然科学基金面上项目(ZR2020MD066);国家自然科学基金重点项目(41430965)。

摘　　要：在全球变暖的背景下,台风活动在未来如何发展是关系到人类社会安全的重大问题之一。受器测记录时间长度的限制,我们对于台风长期的发展与演化机制的认识还不充分。从东海内陆架泥质区的沉积记录中提取台风信息,是了解几千年来影响我国的台风演变规律的有效手段。但是,其他极端事件,尤其是冬季寒潮,会影响台风沉积事件识别的准确性。台风与冬季寒潮大风沉积事件的辨识也是台风活动重建的难点之一。利用布放在东海内陆架泥质区的四脚架观测系统,分别获取了台风“天鹅”和冬季寒潮大风期间的海水温度、盐度、悬浮体浓度和海流等数据,并结合近海观测浮标的风速、风向和波浪等数据,探讨了台风与冬季寒潮沉积动力过程的差异。结果表明,台风与冬季寒潮在风向、有效波高和近底层流速变化上有一定的相似性,但是台风较高的强度更容易引起近底层沉积物的再悬浮;台风经过时,高浓度悬浮体主要来自海底沉积物的再悬浮,而冬季寒潮期间高浓度悬浮体与长江入海物质的输入有关。由于台风和冬季寒潮近底层海流流向的差异,在东海内陆架泥质区向海一侧边缘沉积记录中的砂层可能代表了台风事件沉积,是研究台风活动规律的良好研究材料。研究结果为从东海泥质区沉积记录中提取更准确的台风信息提供了科学参考。One of the major challenges addressing human life safety in the context of global warming is how typhoon activity may develop in the future.Our understanding of typhoon long-term development and evolution mechanisms is limited by the duration of instrumental recording.Extraction of typhoon information from sedimentary records in the muddy area of the East China Sea inner shelf is an effective method for understanding the evolution patterns of typhoons that have impacted China over the past thousands of years.The precision of typhoon event detection,however,might be affected by other extreme events,such as winter cold waves.One of the difficulties in reconstructing typhoon activity is to identify typhoon and winter cold wave deposition events.Using a quadripod observation system placed in the muddy area of the East China Sea inner shelf,seawater temperature,salinity,suspended sediment concentration,and currents during Typhoon Goni and winter cold waves were measured,and the differences in sedimentary dynamic processes between typhoons and winter cold waves were then discussed by combining wind speed,wind direction,and wave data from offshore observation buoys.Observations on typhoons and winter cold waves showed certain similarities in the changes in wind direction,significant wave height,and near-bottom current velocity,but typhoons′higher strength made it easier to resuspend seabed sediments.Typhoon-related high suspended sediment concentrations are mostly caused by the resuspension of seabed sediments,whereas high suspended sediment concentrations during winter cold waves are primarily caused by Yangtze River discharge.Sand layers in the sedimentary record of the seaward side edge of the inner shelf muddy area in the East China Sea are likely to represent typhoon event deposition because of the difference in the direction of the near-bottom current between typhoons and winter cold waves.Therefore,event deposition layers are good research materials for studying the variation patterns of typhoon activity.The fi

关 键 词：台风 冬季寒潮 现场观测 东海 

分 类 号：P736.2[天文地球—海洋地质]