Nitrogen uptake regime regulated by ice melting during austral summer in the Prydz Bay, Antarctica  

作　　者：Run Zhang Qiang Ma Min Chen Minfang Zheng Jianping Cao Yusheng Qiu 

机构地区：[1]College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China [2]Key Laboratory of Estuarine Ecological Security and Enviromental Health, Xiamen University Tan Kah Kee College, Zhangzhou 363105, China

出　　处：《Acta Oceanologica Sinica》2019年第8期1-7,共7页海洋学报（英文版）

基　　金：The National Natural Science Foundation of China under contract No.41676174;the Foundation for Innovative Research Groups of the National Natural Science Foundation of China under contract No.41721005;the Science and Technology Basic Resources Investigation Program of China under contract No.2017FY201403

摘　　要：Using a combination of stable isotope(15N) and radionuclide(226Ra) analyses, we examine possible controls on the interactions between melting ice and the uptake of nitrogen in the Prydz Bay during the 2006 austral summer.We find that specific rates of uptake for nitrate and ammonium correlate positively to their concentrations, thus suggesting a substrate effect. In the study area, we observe that regions along open, oceanic water have high fratios(nitrate uptake/nitrate+ammonium uptake), while areas near the Amery Ice Shelf have significantly low fratios. Further analysis reveals a negative correlation between the f-ratio and the melt water fraction, thus implying that the melting of ice plays an essential role in regulating pelagic N dynamics in the Southern Ocean(SO). Stratification, produced by melting ice, should profoundly affect the efficiency of the SO’s biological pump and consequently affect the concentration of CO2 in the atmosphere. Results presented in this study add information to an already significant base of understanding of the controls on pelagic C and N dynamics in the SO. This provides unique insights for either interpreting past changes in geologic records or for predicting future climate change trends.Using a combination of stable isotope(15N) and radionuclide(226Ra) analyses, we examine possible controls on the interactions between melting ice and the uptake of nitrogen in the Prydz Bay during the 2006 austral summer.We find that specific rates of uptake for nitrate and ammonium correlate positively to their concentrations, thus suggesting a substrate effect. In the study area, we observe that regions along open, oceanic water have high fratios（nitrate uptake/nitrate+ammonium uptake）, while areas near the Amery Ice Shelf have significantly low fratios. Further analysis reveals a negative correlation between the f-ratio and the melt water fraction, thus implying that the melting of ice plays an essential role in regulating pelagic N dynamics in the Southern Ocean（SO）. Stratification, produced by melting ice, should profoundly affect the efficiency of the SO’s biological pump and consequently affect the concentration of CO2 in the atmosphere. Results presented in this study add information to an already significant base of understanding of the controls on pelagic C and N dynamics in the SO. This provides unique insights for either interpreting past changes in geologic records or for predicting future climate change trends.

关 键 词：nitrogen UPTAKE REGIME ICE MELTING PRYDZ Bay ANTARCTICA 

分 类 号：P[天文地球]