基于O2/Ar比值估算海洋混合层群落净生产力的研究进展

群落净生产力(NCP)是海洋混合层中光合作用和群落呼吸作用的差值,代表了从表层海水向深层海洋输送的最大有机质量,是衡量生物活动对上层海洋碳循环影响的有效指标。海洋混合层的溶解氧浓度主要受物理过程和生物过程控制,而惰性气体氩(Ar)的分布主要受物理过程以及温度和盐度对溶解度的影响,由于O2和Ar具有相似的物理特性,因此氧氩比值(O2/Ar)消除了物理过程对海水中溶解氧的影响,其偏离平衡值的量(ΔO 2/Ar)可表征生物过饱和氧,并可据此估算群落净生产力。随着质谱技术的发展,连续走航测定O2/Ar比值技术得到广泛应用并可以获得高时空分辨率NCP分布,因此成为估算海洋混合层NCP的重要方法。本文介绍了基于O2/Ar比值法估算群落净生产力的原理,综述了用O2/Ar比值法估算海洋混合层中群落净生产力的研究进展,探讨了估算模型中存在的不足及解决办法,并对其未来发展方向做了展望。

Advances in Studies of Net Community Production Based on Oxygen/Argon Ratio

Net community production(NCP)is the difference between gross primary production and the community’s combined autotrophic and heterotrophic respiration,representing the largest organic matter transported from surface waters to the deep ocean,and is a good indicator of the impact of biological activity on the upper ocean carbon cycle.Mixed layer Ar is only affected by physical saturation mechanisms whereas O2 responds to both biological and physical mechanisms.Simultaneous O2 and Ar measurements in surface seawater allow one to estimate oceanic O2 outgassing and to probe oceanic productivity.With the progress in mass spectrometer,continuous underway measurement systems have been developed for high resolution measurement of O2/Ar ratio and subsequent estimation of NCP.The authors introduced the principle of estimating net community production based on oxygen/argon ratio,reviewed the advances on the studies of net community production based on oxygen/argon ratio,discussed the problems existed in its estimating model and possible solutions,and its development direction is prospected in the future.