Carbonate system dynamics in coral reef

(1)对雪子岛珊瑚礁的碳酸盐系统组分进行了5年的系统观测。海水PCO2表现出典型的日变化规律：白天低，夜间低，反映了白天光合作用和钙化作用旺盛，而夜间呼吸速率较高。考虑到礁区水流，成功构建了动力盒模型，以计算碳酸盐岩体系组分的变化，解释珊瑚礁内PCO2的日变化。对珊瑚礁PCO2变化的频率分析表明，主要变化频率为26.7 h，提示了月球系统控制珊瑚礁PCO2的可能机制。另一种频率变化，如13或6.5小时也被发现。除短期变化外，PCO2的长期变化也表现为PCO2的逐月阻塞变化，并形成季节变化。长期PCO2变化的数值分析对于验证珊瑚礁碳酸盐系统变化与全球环境变化之间的关系至关重要(5)。本研究建立的动力箱模型成功地应用于复联珊瑚礁碳酸盐体系。如上所示，本研究项目成功建立了评价珊瑚礁碳酸盐体系变化的基本方法。

(1).Carbonate system components are systematically observed for 5 years at coral reef of Sesoko-jima Island. PCO2 in sea water showed typical diurnal patterns : low in daytime and low in night time, which reflected the high photosynthesis and calcification in daytime, and high respiration rate at night time.(2).Considering the water flow in reef area, dynamical Box model was successfully constructed in order to calculate the carbonate system component variation and to explain the diurnal PCO2 variation in coral reef.(3).Frequency analysis of PCO2 variation in coral reef revealed that the main variation frequency was 26.7 hours, which suggested the possible mechanism of lunar system to control PCO2 in coral reef. Another frequencies variation such as 13 or 6.5 hours are also found.(4).Eliminating the short term variations, longer term variation of PCO2 also showed monthly blockage change of PCO2 and forms seasonal variation. Numerical analysis of long term PCO2 variation is important to verify the relationship between carbonate system variation in coral reef and the global environmental change(5).Dynamical Box model developed in this study is successfully applied to the carbonate system of Re-Union coral reef.(6).As shown above, fundamental methods to evaluate the carbonate system variation in coral reef are successfully established in this research project.