GOSAT卫星数据监测中国大陆上空CO2浓度时空变化特征

中国地区大气CO2浓度对全球气候变化有重要的影响。本文基于日本GOSAT卫星短波红外CO2的长期观测数据,对2010年-2016年中国大陆上空CO2浓度的分布特征和变化趋势进行分析研究。利用高精度的地基TCCON站点CO2观测对GOSAT CO2数据进行精度验证,结果表明,GOSAT CO2具有较高的精度,相对TCCON CO2的偏差为-1.04±2.10 ppm,两者的相关系数高达0.90;利用中国地区7年的GOSAT CO2观测数据分析研究显示,CO2浓度高值主要分布在中国的浙江-江苏-安徽地区、京津冀地区和湖南-湖北-河南-陕西地区;截至2016年,中国大部地区CO2浓度超过400 ppm;中国大陆CO2平均浓度呈现明显的逐年增长趋势,从2010年的387.76 ppm增长到2016年的402.18 ppm,年增长率约为2.31 ppm/a,略高于同期全球平均水平。

Temporal and distribution characteristic of CO2 concentration over China based on GOSAT satellite data

Atmospheric CO ₂ concentration over China has significant effects on the global climate change. To reliably predict the impact of atmospheric CO ₂ on global climate change, it is necessary to clarify the distribution and variation of atmospheric CO ₂ concentration. Based on long term short-wavelength infrared CO ₂ dataset observed by GOSAT, the temporal variation and spatial distribution characteristics and variation trend of atmospheric CO ₂ concentration was investigated and analysed over China during 2010 to 2016. To ensure the quality of GOSAT CO ₂ dataset used in this paper, the GOSAT XCO ₂ dataset was validated with high precise XCO ₂ from ground-based TCCON sites. Multi-year mean of XCO ₂ was illustrated to show the spatial heterogeneity of CO ₂ concentration over China. Interannual variation and annual growth of XCO ₂ was also presented and discussed. The results showed that GOSAT XCO ₂ dataset was biased by -1.04±2.10 ppm with respect to TCCON XCO ₂, and the correlation coefficient was 0.90 between them. Seven years (2010~2016) of GOSAT CO ₂ dataset showed that high CO ₂ concentrations were mainly located in Zhejiang-Jiangsu-Anhui region, Beijing-Tianjin-Hebei region, and Hunan-Hubei-Henan-Shanxi region in China. The CO ₂ concentration reached 400 ppm over most regions in China until 2016. The annual average of CO ₂ concentration showed an increase trend year by year over China, increasing from 387.76 in 2010 to 402.18 ppm in 2016. The annual growth rate of CO ₂ concentration was evaluated to be 2.31 ppm/a during this period over China, which was slightly higher than the average in the world. This paper shows that the CO ₂ concentration observations from satellites could provide some references for the climate change response strategies and atmospheric environment control.