依据国家自然科学基金委公共航次2010年和2012年4个航次在渤黄海海域获得的现场悬浮体浓度数据及CTD海洋水文观测数据,结合MODIS L1B数据第4波段反射率值,建立了悬浮体浓度(SSC)与反射率强度的反演模型,反演了渤黄海海域表层悬浮体的月均分布。综合现场实测数据和遥感反演结果,研究渤黄海海域悬浮体的季节性变化特征。利用HYCOM数值模拟得到的各个层位流速数据,分析渤黄海海域主要断面的悬浮体扩散通量。结果表明,渤黄海海域表层悬浮体浓度高值区主要分布在黄河口莱州湾及渤海湾附近沿岸海域、山东半岛沿岸、苏北浅滩至长江口一带、罗洲群岛附近海域以及沿岸其他小河流入海口。渤黄海海域水体结构具有季节性变化特征。夏季,水体上下温差大、层化较强、水动力条件较弱,海域悬浮体浓度相对较低。而在冬季,海域气温较低,水体上下温差小,同时,渤黄海海域强劲的东北风盛行,水体混合强烈,海域悬浮体浓度较高。同时,黄海暖流和山东半岛沿岸流等流系加强,携带悬浮体的能力和效率均大大提高,冬季成为海域悬浮体输运的主要季节。在冬季,黄河三角洲沿岸、山东半岛沿岸以及苏北海岸等区域在强动力作用下的再悬浮成为海域的悬浮体主要来源。黄河三角洲沿岸再悬浮的沉积物通过渤海海峡的南端输入北黄海,在沿岸流的作用下悬浮体输送通量沿程增大,经过成山头海域后转向南输送,输送通量沿程减少,沉积物在黄海中部泥质沉积区汇聚。沉积动力的分析结果显示,冬春季节在山东半岛区域形成的混合锋面对悬浮体的输运路径有重要的影响。
Based on the observed data of suspended sediment concentration(SSC)and hydrographical data in the Bohai and Yellow Sea in different seasons of 2010 and 2012,in combination with the MODIS data,this paper presented the seasonal distribution of suspended sediment in the Bohai and Yellow Sea.The correlation between the observed surface SSC and the reflectance obtained from MODIS presented the seasonal distributions of regional surface SSC.The results indicated that the high SSC mostly distributed in areas around the Yellow River Delta,the coastal area of the Shandong Peninsula and the Jiangsu Province.The regional distribution of SSC presented strong seasonal variability as high SSC was found in wintertime while low SSC in summertime,corresponding to the seasonal variation of hydrodynamics.In wintertime,the resuspended sediment from the subaqueous Yellow River Delta was exported to the northern Yellow Sea through the souther Bohai Strait and was transported along the coast of Shandong Peninsula by the monsoon-enhanced coastal currents,as the sediment flux increased along the pathway.At the headland of Shandong Peninsula,the sediment was transported southwards to the southern Yellow Sea together with decreasing sediment flux,which indicated that the suspended sediment mostly accumulated the muddy area of central Yellow Sea.The mixing front identified in the winter-spring season around the Shandong Peninsula constrained the sediment transport within the shallow coastal area,which might play a important role in dominating the sediment transport pathway.