基于稳定同位素技术的典型区域大气CO2时空分异及其驱动机制研究

CO2 is the most important greenhouse gas whose carbon cycle and the source condition are not only fundamental to know and control global climate change, but also the core part of current global change research. The atmosphere as the final receptor of greenhouse gas emissions from all kinds of natural and human activity, the estimate for source amount of CO2 still exists a lot of uncertainty, and the carbon oxygen stable isotopes of CO2 in the atmosphere is important tracer used to distinguish CO2 released by photosynthesis from the relative share of the human activities, sea, biosphere as well as the overall breathe amount of ecological system. In the research, the atmospheric CO2 and its δ13C and δ18O were taken as the main research object, by sampling and online observation analysis of our country's five field sites (Waliguan in Qinghai, Shangdianzi in Beijing, Lin'an in Zhejiang, Longfegnshan in Heilongjiang, Heyuan in Guangdong) and Beijing city regions, it was explored that the spatial and temporal variation characteristics and the regional differentiation of δ13C and δ18O of atmospheric CO2 in our country different typical region, quantitative analysis was done for different ratio of the atmospheric CO2 source, it was further studied that atmospheric CO2 concentration in different areas and the drive mechanism of the isotopic composition with changing proportion and then scientific evaluation will be done for the present situation and development trend of atmospheric CO2 under China's current economic development level and a scientific foundation is provided for positive response to climate change.

CO2是最重要的温室气体，其碳循环过程和源汇收支状况是认识和控制全球气候变化的基础，也是当前全球变化研究的关键科学问题。大气作为各种自然及人为活动温室气体排放的最终受体，其CO2源汇量的估算仍存在很大的不确定性。CO2中的碳氧稳定同位素可区分陆地与海洋生物圈、生态系统呼吸与光合作用间的配比关系，为大气CO2源汇研究提供依据。本研究将以大气中CO2及其δ13C和δ18O相关关系为切入点，通过采样及在线观测分析，首次获得我国"京津冀"、"长三角"、"珠三角"及"东北平原"四大典型区域大气CO2浓度及其同位素观测数据，深入研究我国不同区域大气CO2时空变化特征及其源汇驱动机制；同时针对多种分析方法因原理不同可能引发的CO2浓度测量偏差，通过对不同CO2浓度及δ13C值梯度序列的分析测试，提出合理的同位素效应校正因子，推进大气CO2浓度观测方法之间的准确性和可比性，有效降低其源汇估算中的不确定性。

CO2是大气中最重要的温室气体，其碳循环过程和源汇收支状况是认识和控制全球气候变化的基础，也是当前全球变化研究的关键科学问题。大气作为各种自然及人为活动温室气体排放的最终受体，其CO2源汇量的估算仍存在很大的不确定性。. 本项目以全球气候变化和温室气体排放为主题，以大气中CO2及其稳定同位素的相关关系为切入点，通过采样及在线观测分析，首次获得我国“京津冀”、“长三角”、“珠三角”及“东北平原”四大典型区域大气CO2浓度及其同位素观测数据，得到基于不同分析系统的CO2浓度及其同位素变化规律，提取出CO2浓度同位素效应校正因子；获得了国际可比的我国多站点同期大气CO2及其同位素观测资料；初步了解了我国典型区域大气CO2浓度及其稳定同位素时空分布、地区间差异、相互比例关系及源汇输送特征。这些研究成果可以为尽快全面掌握我国不同区域大气温室气体浓度水平差异及源汇变化机理，进而客观准确地评估我国温室气体排放、吸收现状及发展趋势，为我国积极应对气候变化内政、外交提供科学基础。. 本项目经过团队成员的共同努力，按期保质保量完成了项目预定任务和目标。此外，结合其他项目支持，出版技术手册和气象行业标准各1份，满足了我国观测站网业务化运行的需求，并进一步规范了科研、业务人员对业务系统的日常操作和运行维护。同时，完成了《中国温室气体公报2015》和《中国温室气体公报2016》，中国气象局专门召开新闻发布会对公报内容进行解读，国内多家权威媒体对公报内容进行了报道和转载，中央电视台也进行了相关报道，引起了相关学者和社会公众的极大关注，可以进一步加快和推动中国气候变化领域的学术研究和社会认可度。