西沙大气二氧化碳浓度变化特征研究  

Study on the concentration variation of CO_2 in the background area of Xisha

作　　者：吕洪刚[1,2] 王海燕[1] 姜亦飞[1,2] 陈海南[3] 乔然[1,2] 王彰贵[1] 

机构地区：[1]国家海洋环境预报中心,北京100081 [2]国家海洋环境预报中心海洋灾害预报技术研究国家海洋局重点实验室,北京100081 [3]国家海洋局三沙海洋环境监测中心站,海南海口570311

出　　处：《海洋学报》2015年第6期21-30,共10页

基　　金：青年科学基金项目(41406036);十二五国家科技支撑项目(2012BAC19B08);海洋公益专项(20120518-2)

摘　　要：CO2是引起全球气候变暖的最重要温室气体。大气中过量CO2被海水吸收后将改变海水中碳酸盐体系的组成,造成海水酸化,危害海洋生态环境。本文采用局部近似回归法对2013年12月—2014年11月期间西沙海洋大气CO2浓度连续监测数据进行筛分,得到西沙大气CO2区域本底浓度。结果表明,西沙大气CO2区域浓度具有明显的日变化和季节变化特征。4个季节西沙大气CO2区域本底浓度日变化均表现为白天低、夜晚高,最高值405.39×10-6(体积比),最低值399.12×10-6(体积比)。西沙大气CO2区域本底浓度季节变化特征表现为春季和冬季高,夏季和秋季低。CO2月平均浓度最高值出现在2013年12月,为406.22×10-6(体积比),最低值出现在2014年9月,为398.68×10-6(体积比)。西沙大气CO2区域本底浓度日变化主要受本区域日照和温度控制。季节变化主要控制因素是南海季风和大气环流,南海尤其是北部海域初级生产力变化和海洋对大气CO2的源/汇调节作用。CO2 is the most important greenhouse gases that cause global warming.After the sea absorb excess CO2 , the composition of carbonate system changes.Consequently,the pH of the seawater will reduce and damage the marine ecological environment.The atmospheric carbon dioxide （CO2 ）was observed at Xisha in the South China Sea from December 2013 to November 2014.A mathematical procedure based on robust local regression was ap-plied to distinguish background and non-background concentration.The CO2 background concentration shows large diurnal and seasonal variations.The CO2 concentration shows lower during daytime and higher during nighttime in four seasons.The maximum is 405.39x10-6 （V/V）and minimum is 399.12x10-6 （V/V）.The CO2 seasonal cy-cle shows higher in spring and winter,lower in summer and autumn.The monthly maximum appears in November 2013 （i.e.,406.22x10-6 （V/V））and the minimum appears in September 2014 [i.e.,398.68x10-6 （V/V）].The diurnal variation of background concentration is mainly affected by sunlight and temperature in the region.And the seasonal variation is controlled by monsoon,atmospheric circulation,photosynthesis,and source or sink of the sea to air.

关 键 词：西沙 南海 大气CO2 本底浓度 

分 类 号：P734.4[天文地球—海洋化学]