台湾海峡南部海域夏季上升流颗粒有机碳含量的逐日变化特征

Abstract

根据2004~2006年夏季台湾海峡南部海域上升流区追踪过程中观测的颗粒有机碳(POC)、叶绿素A(CHl-A)、总悬浮颗粒物(TSM)含量数据,3个年份夏季上升流区POC含量范围分别为0.115 0~0.244 4、0.139 1~0.650 8、0.106 8~0.535 0 Mg/dM3,其平均值比同年份其他断面POC含量的平均值高.POC含量及CCHl-A/CPOC值的逐日变化对上升流事件的响应较好,反映出现场生产力对颗粒态有机碳的贡献与上升流发生过程的耦合;CCHl-A/CPOC值与CHl-A含量呈正相关,在上升流的稳定期和衰减期,二者关系表现形式有所不同,能细分上升流事件的过程;上升流区的CCHl-A/CPOC值相对偏小,反映了上升流区浮游生物的高营养转换效率.POC和TSM含量的逐日变化关系在不同年份有不同表现,TSM含量对POC含量的影响存在促进和限制的可能;颗粒有机质含量占TSM比例的变化规律不明显,CPOC/CTSM值的逐日变化不能较好地响应上升流事件;CPOC/CTSM值与TSM含量关系均呈负相关;受陆源有机物的补充及现场有机物的生物地球化学过程的影响,CPOC/CTSM值与TSM含量关系更为复杂.

Particulate organic carbon(POC),chlorophyll a(chl-a)and total suspended matter(TSM)were analysed in the Taiwan Strait in the summer upwelling period in the cruises of 2004--2006.POC concentrations were found as 0.115 0--0.244 4,0.139 1--0.650 8,0.106 8--0.535 0 mg/dm3 in summer of 2004--2006,respectively.The average concentrations of POC in upwelling area were higher than other summer cruises.The ratio Cchl-a/CPOC was 0.002--0.024.The day-to-day changes in the concentration of POC and Cchl-a/CPOC reflected the in situ productivity contributed by POC and a well coupling with the upwelling process.The positive correlation between ratio Cchl-a/CPOC and chl-a was found in this three years.The relation of Cchl-a/CPOC,which was low in the upwelling area,and chl-a was different between the stable phase and decline phase.It suggests that there is a high trophic transfer efficiency along the food chain in upwelling dominated area.The relationship of day-to-day change in POC and TSM concentration was different in the summer of 2004--2006.The possibility of promotion and limitation on POC both existed by the influence of TSM,which varied from 0.80 to 12.50 mg/dm3 in the upwelling area.The variation of the ratio of organic matter in TSM was not clear.The day-to-day change in CPOC/CTSM didn't responded obviously to upwelling event.The negative correlation between ratio CPOC/CTSM and TSM was found,indicating that the contribution of POC to TSM decreased with increasing TSM.Because of the supply of terrestrial matter and the influence of biogeochemical processes of organic matter,the relation between CPOC/CTSM and CTSM became much complicated.