摘要
对北太平洋西部海域、苏禄海及印尼海、中国南海、印度洋东部海域、孟加拉湾及安达曼海等表层水体中放射性核素137Cs的活度进行了测定。结果表明,上述海域表层水体中137Cs活度显示了较大的变化范围,最低值出现在南极附近的南大洋(1.1Bqm-3),较高的活度值则出现在北太平洋西部海域及中国南海(3Bqm-3)。在所研究水域范围内,137Cs活度的纬度分布特征并没有完全有效地反映出137Cs的全球理论大气沉降趋势及其纬度效应。综合本研究及Miyake等人(1988)的测定结果,我们计算出137Cs自表层海水中的析出速率在苏禄海及印尼海约为0.016/a,在孟加拉湾及安达曼海约为0.033/a,在中国南海约为0.029/a,这一结果明显低于西北太平洋日本沿海表层水体中137Cs的析出速率。这可能是因为在这些海域,横向及纵向的水体混合过程相对都较慢,而且颗粒物对137Cs的吸附析出过程也比较弱所致。
The ^137Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The ^137Cs activities showed a wide range of variation with values ranging from 1.1 Bq m^-3 in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m^-3 in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of ^137Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of ^137Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. （ 1988 ） and this study to be 0.016 yr^-1 in the Sulu and Indonesian Seas, 0. 033 yr^-1 in the Bay of Bengal and Andaman Sea, and 0.029 yr^-1 in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to the less horizontal and vertical mixing of water masses and less scavenging.
出处
《海洋通报》
CAS
CSCD
北大核心
2006年第6期85-90,共6页
Marine Science Bulletin
基金
国家自然科学基金面上项目(40573005)
日本文部省科技振兴基金(MASFLEX和GCMAPS)联合赞助
