夏季南极普里兹湾氮吸收受融冰调控

本研究将稳定同位素（¹⁵N）与放射性核素（²²⁶Ra）示踪相结合，探讨了2006年夏季南极普里兹湾融冰过程对氮吸收的调控作用。硝酸盐及铵盐的比吸收速率均与浓度呈正相关关系，表明底物浓度效应的存在。开阔洋区具有较高的f比值，而在埃默里冰架附近f比值低得多。f比值与冰融水份额之间存在负相关关系，暗示融冰过程在调控水体氮吸收方面起着重要作用。融冰改变了当地上层水体的层化条件，显著地影响南大洋的生物泵效率及对大气二氧化碳的吸收。本研究为南大洋上层水体碳、氮动力学的调控机制提供了新的认识，且有助于对历史记录的解读及对未来气候变化的预测。

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

Using a combination of stable isotope(~(15)N) and radionuclide(~(226)Ra) 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 CO_2 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.