西北太平洋春、秋季悬浮颗粒物的粒径变化与物质组分

Composition and particle size change of suspended particulate matter in spring and autumn in the northwest Pacific Ocean

为了解日本以东的西北太平洋200m以浅上层水体悬浮颗粒物的粒径变化与物质组分,分别于2015年5月和9月在该海区应用LISST-100X型现场激光粒度仪进行了悬浮体粒径分布的测量,并采集悬浮体水样采用扫描电镜及能谱分析悬浮颗粒物的物质组分.结果表明,研究区的悬浮颗粒物主要由大粒径颗粒(大于133μm)组成,并在100m以浅的上表层集中分布,其余层位颗粒含量较少.秋季悬浮体浓度远高于春季,但大粒径颗粒所占的比重明显降低,中等大小的颗粒(36~133μm)所占比重相应增加,中等粒径颗粒和细小粒径颗粒(小于36μm)在200m水层以浅分布较均匀,并有随着粒径的增大悬浮体浓度逐渐增加的趋势.悬浮颗粒物组成成分主要为单矿物碎屑、生物碎屑、絮凝体,主要来源于海洋浮游生物和陆源输入.悬浮体浓度及粒径分布特征主要受生物生长、大陆风尘和洋流输送等因素的影响.

To understand the composition and particle size distribution in spring and autumn in the northwest Pacific Ocean, east of Japan, LISST-100X instrument was used for the particle size distribution of suspended particulate matter（ SPM） in the top 200 m surface water in May and September, 2015. The major component of suspended par-ticulate matter was analyzed with Scanning Electron Microprobe （ SEM ） and Energy Dispersive Spectrometer （EDS）. The results shows that the SPM in the study area is mainly composed of large particle size greater than 133 （xm and concentrated in certain layers. Concentration of SPM in autumn is much higher than in spring. The proportion of large particle size particles is decreased while the proportion of medium-sized particles increase and medium and small-sized particles distribution is more uniform in the water column 〈 200m. Such trend is increas-ing with particle diameter. The main components of suspended particulate matter are single mineral particles, bio-logical particles and floes that mainly deprived from marine plankton and terrestrial material transport. Concentra-tion and particle size distribution of the suspended particulates are controlled by biological growth, the continental input of aeolian sediment, dust and ocean current conditions.