| 摘要: |
| 2002年8月，沿穿过黄海冷水团的青岛至济州岛断面，在4个站位放置沉积物捕获器采集沉降颗粒物。镜检发现无机颗粒物、生物粪球以及混杂聚合体是本断面沉降颗粒物主要类型。测定结果显示沉降颗粒物中的颗粒有机碳(POC)、颗粒有机氮(PON)、颗粒碳(PC)、颗粒氮(PN)和颗粒磷(PP)的百分含量均呈现从表层到底层逐渐下降的趋势。采用两个改进的模型对底层颗粒物再悬浮比率进行了计算，显示黄海海域夏季底层沉降颗粒物再悬浮比率为90％-96％，表明底层沉降颗粒物主要来源于沉积物的再悬浮。两模型所得结果一致，证明用温跃层底部颗粒物沉降通量代表水体中颗粒物净沉降通量的假设是合理的。水体中颗粒物、POC及PON的净沉降通量(±SE)分别为(12.65±3.55)g／(m2·d)、(0.29±0.04)g／(m2·d)和(O.06±O.01)g／(m2·d)。 |
| 关键词: 沉降颗粒物，颗粒物通量模型，沉降通量，再悬浮比率，温跃层，黄海 |
| DOI： |
| 分类号: |
| 基金项目:国家重点基础研究发展规划项目，G19990437号 |
附件 |
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| VERTICAL FLUX OF THE SETTLING PARTICULATE MATTER IN THE WATER COLUMN OF THE YELLOW SEA IN SUMMER |
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ZHANG Yan-Song1,2, ZHANG Fei-Jun1,3, GUO Xue-Wu1, ZHANG Man-Ping2
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1.Yellow Sea Fisheries Research Institute，Chinese Academy of Fishery Sciences，Key Laboratory for Sustainable Utilization of Marine Fisheries Resource，Ministry of Agriculture;2.College of Chemistry and Chemical Engineering，Ocean University of China;3.Fisheries College，Ocean University of China
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| Abstract: |
| Settling particulate matter (SPM) was collected using Bloesch multi-tube sediment traps at four stations through a transect from Qingdao to Chejudo Island in August 2002. The transect crossed the Yellow Sea Cold Water Mass, which has two cold centers during the survey. The sediment traps were surface tethered and planted in three layers at each station, the upper and lower layer of the thermocline above the Cold Water Mass, and the bottom layer of the water column. Of the SPM, the types, the contents of organic carbon, organic nitrogen, total carbon, total nitrogen, and total phosphorous, the fluxes, and the resuspension ratio in the bottom layer were analyzed in this paper. Two particulate flux models (Model Ⅰ and Model Ⅱ) were improved and used to calculate the resuspension ratio, with a key hypothesis in Model Ⅰ that the vertical flux of the SPM in the lower layer of the thermocline equals to the net vertical flux of SPM in the water column. A X value, i.e. the percent of total resuspension flux constituted by the resuspension flux from the bottom sediments surrounding the sampling station, was deduced from Model I to estimate the contribution of lateral current to the total resuspension flux. Microscopical examination showed that inorganic particulates, fecal pellets, and miscellaneous aggregates were the major types of SPM. Inorganic particulates dominated SPM in the bottom layer due to intensive sediment resuspension at whole stations. A large amount of fecal pellets were found in the lower layer of the thermocline, indicating that the thermocline is the main site of biogenic SPM production. As measured, content of organic carbon, organic nitrogen, total carbon, total nitrogen, and total phosphorous of SPM decreased with the depth of water column. Content of organic carbon and organic nitrogen in the upper layer of the thermocline was much higher at the outer stations in the Cold Water Mass than that at the middle stations. This may be because the coastal current and the warm current of the Yellow Sea influence the surface layer of the water column at the sides of the Cold Water Mass. The organic carbon fluxes in the lower layer of the thermocline were higher at stations in upwelling areas than those at stations where no upwelling existed. This may be because the upwelling drives a greater amount of nutrients upwards. The resuspension ratios were calculated from 90% to 96% among stations, and the values were not significantly different between the two particulate flux models mentioned above. This indicates that the hypothesis in Model I is acceptable, the vertical flux of SPM in the lower layer of thermocline can be taken as the net vertical flux of SPM in the water column when the latter was unavailable. As results, the mean(±SE)net vertical fluxes of SPM, particulate organic carbon, and particulate organic nitrogen were valued (12.65±3.55), (0.29±0.04), and(0.06±0.01)g/(m2?d), respectively. The X values were estimated from 47.1% to 79.6% among stations. The bottom lateral current contributed up to 52.9% of the total resuspension flux at the station between the two cold centers of the Cold Water Mass. |
| Key words: Settling particulate matter(SPM), Particulate flux model, Sedimentation flux, Resuspension ratio, Th ermocline, Yellow Sea |
