南沙海域基于^234Th-^238U不平衡的颗粒态有机碳输出通量研究  

Particulate organic carbon export fluxes in Nansha Islands sea area estimated from ^(234)Th-^(238)U disequilibria

作　　者：尹明端[1,2] 马豪[1,2,3] 何建华[1,2] 曾宪章[1,2] 曽文义 

机构地区：[1]国家海洋局海洋-大气化学与全球变化重点实验室 [2]国家海洋局第三海洋研究所,福建厦门361005 [3]清华大学工程物理系,北京100084

出　　处：《热带海洋学报》2008年第2期64-69,共6页Journal of Tropical Oceanography

基　　金：南沙群岛及其邻近海区综合调查,国家海洋局海洋生态系统与生物地球化学重点实验室开放研究基金项目(LMEB200705);基本科研业务费专项资金项目(海三科200703);国家资源勘查专项基金项目(118-03-02-02)

摘　　要：利用234Th-238U不平衡方法研究南沙群岛海域春季真光层颗粒动力学性质,测定了4个站位水柱中颗粒态有机碳(POC)、溶解态及颗粒态234Th和238U的含量,讨论了各站位水柱中234Th/238U)A.R.的垂直分布。运用稳态箱式模型计算各站位不同水层中溶解态234Th相对于清除至颗粒物的平均停留时间和颗粒态234Th相对于迁出作用的平均停留时间。结合POC/234ThP比值,用两种方法估算出各站位的颗粒态有机碳输出通量分别为8.51—34.94和13.28—50.06mmol.(m2.d)-1。两种方法结果一致,说明234Th是表征POC循环的良好示踪剂。Particle dynamics in the euphotic zone was studied at four stations in the Nansha Islands sea area during the 2002 spring cruise by the application of ^234Th-^238U disequilibria. The contents of the particulate organic carbon （POC）, ^234Th （dissolved and particulate） and ^238U were determined and the profiles of ^234Th/^238U）A.R. were discussed at the four stations. The profiles of dissolved and particulate 234Th and a steady state box model were used to quantify the dissolved ^234Th scavenging fluxes, particulate ^234Th re moval fluxes and their resident times. According to Poe/TM Thp ratios, the POC export fluxes at the four stations derived from the two different approaches ranged from 8.51 to 34.94 mmol/ ·（m^2·d）^-1 and 13.28 to 50.06 mmol/ ·（m^2·d）^-1, respectively.

关 键 词：南沙海域 ^234Th-^238 U不平衡 POC输出通量 

分 类 号：P734[天文地球—海洋化学]