摘要
用锰纤维富集-射气法测量了北黄海水体的224Ra,研究了该海域夏季和冬季2个季节224Ra比活度及其垂直分布,并对其进行了比较研究.北黄海夏季224Ra比活度为0.24～3.48Bq/m3,平均值为1.14Bq/m3;冬季224Ra比活度为0.37～6.68Bq/m3,平均值为0.94Bq/m3.北黄海的表层水有3个224Ra高值区,分别位于东北部海域、渤海海峡南部和北黄海中北部海区.30m水深将224Ra比活度的垂直分布分成上层和下层2层.在0～30m水层,夏季,随着水深增加224Ra比活度逐渐增加,比活度变化较小;冬季部分站位由表层向下224Ra比活度逐渐降低.30m水深以下,224Ra比活度随着水深的增加而增加,而且变化幅度较大.由224Ra比活度的垂直分布得出该海域的垂直涡动扩散系数为2.5～43.5cm2/s,夏季北黄海冷水团中心海域底层溶解态化学物质输运补给到上层所经历的时间为9～15d左右.
224 Ra in seawater of northern Yellow Sea were measured using Mn-fiber adsorption-emanation method. The horizontal and vertical distribution of 224 Ra in the sea in summer and winter were studied. The 224 Ra activities were 0.54 - 3.48Bq/m3 with an average of 1. 14Bq/m3 in summer and 0.37 ～ 6.68Bq/m3 with an average of 0. 94 Bq/m3 in winter. There were 3 high ^224 Ra areas in the northern Yellow Sea：northeast area, southern Bohai Strait, and central and northern area. 30m layer divided the 224 Ra vertical distribution into two parts ： upper layer and lower layer. The upper layer,0 - 30m 224Ra increased with the depth and varied slightly in summer and =4Ra decreased with depth for some stations in winter. The layer below 30m,224 Ra increased with depth and varied gready. The vertical eddy diffusion coefficients based on the vertical distributions of 224Ra were 2.5 ～43.5cm2/s. It took 9 ～ 15d for the dissolved chemical matters in central area of the Yellow Sea cold water mass to transporte from the bottom layer to the upper layer in summer time.
出处
《台湾海峡》
CAS
CSCD
北大核心
2010年第1期47-57,共11页
Journal of Oceanography In Taiwan Strait
基金
国家基础研究发展计划资助项目(2005CB422305)
关键词
海洋化学
同位素地球化学
224Ra
空间分布
浅海混合
垂直涡动扩散
北黄海
marine chemistry
isotope geochemistry
^224 Ra
spacial distribution
shallow sea mixing
vertical eddydiffusion
northern Yellow Sea
