东海与黑潮海水中宇宙射线成因核素^(10)Be的研究  

^（10）Be behavior in the East China Sea and the influence from the Kuroshio Current

作　　者：杨永亮[1] Masashi Kusakabe John R.Southon 

机构地区：[1]青岛大学环境科学系,山东青岛266071 [2]日本海洋科学技术中心 [3]Lawrence-Livermore国家实验室

出　　处：《地球化学》2001年第4期305-314,共10页Geochimica

摘　　要：讨论了中日东海MASFLEX合作计划中调查的东海及冲绳海槽海水中溶解态10Be浓度水平及垂直剖面的结果。在这个海区影响10Be浓度的因素主要有生物生产力、悬浮颗粒物的再溶解,以及长江水与黑潮水的混合程度。在样品采集期间(夏季和秋季),东海水柱呈分层状态。通常10Be的垂直剖面可以分成三层,即表面混合层、10Be释放层和底层。表层水10Be的浓度从长江口到黑潮逐渐增大,在黑潮的边缘则剧烈增大。10Be的垂直分布表明,在夏季10Be富集在长江口附近和大陆架中部的底层水中,这两个富集海区是分开的,很可能是由大陆沿岸水所隔开。在秋季,10Be在底层水中的富集仅仅出现在东海大陆架的西部。这个现象是和受季风影响的东海海流的变化相一致的。黑潮分支在台湾东北外海向东海南部侵入对10Be的影响要比黑潮主干流本身更加重要显著。由箱式模型所得到的10Be质量平衡计算结果表明,来自黑潮的10Be输入要比长江及大气沉降的输入更为重要。输入东海的10Be大约81%进入到沉积物中,而19%的10Be则通过海流和水交换流出东海。在东海的10Be沉积通量是10Be全球平均大气生产率的5倍左右,因而东海是10Be的一个重要汇集地。Dissolved 10 Be concentration profiles in sea water of the East China Sea and the Okinaw a Trough in autumn 1993and summer 1994have been investigated.The results show that 10 Be concentrations in this area are mainly controlled by surface biological productivity,redissolution o f suspended particulate matter,and the degree of mixing of Changjiang River(the Yangtze River)with the Kuroshio waters.During the sampling periods(summer and autumn ),the East China Sea was well stratified.Generally the 10 Be water depth profiles can be divided into three layers:the surface mixing lay er,the particulate 10 Be regeneration layer and the bottom layer.The 10 Be concentrations in surface water increase gradually towards the kuroshi o and increase sharply at the edge of t he Kuroshio Current.Vertical distrib utions of 10 Be show that in the summer 10 Be is enriched in the bottom waters near the Yangtze River estuary and the cen tral continental shelf.The two enriched areas are separated,probably b y an intrusion of the continental coasta l water.In the autumn,10 Be enrichment in bottom water occurred only in the western part of the continent shelf.This phenomenon is consistent with t he seasonal circulation pattern change of the current induced by the monsoon.The i nfluence of the Kuroshio branch intr usion in the southern East China Sea f rom northeast waters of Taiwan on 10 Be may be more significant than the kuroshio mainstream.Box model results indicate that 10 Be input from the Kuroshio Current is more important than from Yangtze Riv er and from atmospheric precipitation.About 81%of 10 Be input to the East China Sea enters i nto the sediments and 19%of 10 Be flows out of the East China Sea by currents and water exchange.The 10 Be sedimentation flux in the East Chi na Sea is nearly five times of the average global 10 Be production rate.Therefore,the East China Sea may be an important sink for 10 Be.

关 键 词：大陆架 东海 黑潮 冲绳海槽 铍同位素 宇宙射线成因核素 季节变化 

分 类 号：P734.24[天文地球—海洋化学] P731.27[天文地球—海洋科学]