Biological productivity and carbon cycling in the Arctic Ocean  

作　　者：CHEN Min HUANG Yipu GUO Laodong CAI Pinghe YANG Weifeng LIU Guangshan QIU Yusheng 

机构地区：[1]Department of Oceanography,Xiamen University,Xiamen 361005,China [2]International Arctic Research Center,University of Alaska,Fairbanks,AK 99775,USA

出　　处：《Chinese Science Bulletin》2002年第12期1037-1040,共4页

基　　金：This work was supported by the Chinese First Arctic Expedition Foundation ; the National Natural Science Foundation of China (Grant No. 40076024).

摘　　要：Primary production, bacterial production, par-ticulate organic carbon fluxes and organic carbon burial rates were quantified during the summer period of 1999 in the Arctic Ocean via 14C uptake, 3H uptake, 234Th/238U disequilibrium and 210Pbex dating, respectively. The integrated primary production in the water column was as high as 197 mmolC/(m2·d) in the Chukchi shelf and was 3.8 mmolC/(m2·d) in the Canada Basin. These rates are higher than those reported previously. The ratios of bacterial production to primary production in the study region were higher than 0.5, indicating that microbial activity is not depressed but important in cold Arctic waters. 234Th/238U dis-equilibria were evident at the station in the Canada Basin. The presence of significant 234Th deficiency suggested that scavenging and removal processes are also important to bio-geochemical cycles of trace elements in the Arctic Ocean. Particulate organic carbon export flux was estimated to be 1.0 mmolC/(m2·d). Measurements of sedimentPrimary production, bacterial production, particulate organic carbon fluxes and organic carbon burial rates were quantified during the summer period of 1999 in the Arctic Ocean via14C uptake,3H uptake,234Th/238U disequilibrium and210Pbex dating, respectively. The integrated primary production in the water column was as high as 197 mmolC/(m2 · d) in the Chukchi shelf and was 3.8 mmolC/(m2 · d) in the Canada Basin. These rates are higher than those reported previously. The ratios of bacterial production to primary production in the study region were higher than 0.5, indicating that microbial activity is not depressed but important in cold Arctic waters.234Th/238U disequilibria were evident at the station in the Canada Basin. The presence of significant234Th deficiency suggested that scavenging and removal processes are also important to biogeochemical cycles of trace elements in the Arctic Ocean. Particulate organic carbon export flux was estimated to be 1.0 mmolC/(m · d). Measurements of sediment excess Pb profile in the Chukchi shelf allowed us to estimate the amount of organic carbon buried in the bottom sediment, which ranged from 25 to 35 mmolC/(m2 · d) and represented about 59%-82% of the mean primary production in the euphotic zone. Overall, our results indicated that the Arctic Ocean has active carbon cycling and is not a biological desert as previously believed. Therefore, the Arctic Ocean may play an important role in the global carbon cycle and climate change.

关 键 词：ARCTIC Ocean primary PRODUCTION bacterial PRODUCTION POC EXPORT flux organic carbon BURIAL rate ISOTOPIC tracer. 

分 类 号：P732[天文地球—海洋科学]