Carbonate system dynamics in coral reef

（1）对濑子岛珊瑚礁的碳酸盐体系组分进行了连续5年的系统观测。海水中PCO 2具有典型的日变化特征：白天低，夜间低，反映了白天高光合作用和高钙化作用，夜间高呼吸作用。（2）在考虑礁区水流的情况下，成功地建立了动力箱模型，计算了珊瑚礁碳酸盐体系组分的变化，解释了珊瑚礁PCO_2的日变化。（3）对珊瑚礁PCO_2变化的频率分析表明，其主要变化频率为26.7 h，这可能是月球系统控制珊瑚礁PCO_2变化的机制。还发现了另一种频率变化，如13或6.5小时。（4）排除短期变化，长期变化也表现为PCO_2的月阻塞变化，形成季节变化。长期PCO 2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具有重要意义（5）。本研究开发的动力箱模型成功应用于Re-Union珊瑚礁碳酸盐系统。（6）综上所述，本研究成功地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.