Simulations of summertime fossil fuel CO2 in the Guanzhong basin, China
Simulations of summertime fossil fuel CO2 in the Guanzhong basin, China
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中国关中盆地夏季化石燃料二氧化碳的模拟
DOI：
10.1016/j.scitotenv.2017.12.021
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发表时间：
2018
影响因子：
9.8
通讯作者：
Guohui Li
中科院分区：
文献类型：
--
作者：
Tian Feng;Weijian Zhou;Shugang Wu;Zhenchuan Niu;Peng Cheng;Xiaohu Xiong;Guohui Li
最近，与Δ14CO2measurements相关的化石燃料二氧化碳模拟研究相当有限，特别是在中国。本研究采用改进的WRF-CHEM模式，在实测co2混合比和Δ14CO2约束下，模拟了2012年夏季关中盆地大气中化石燃料co2的δCO2ff。模型较好地捕捉了观测到的co2混合比和Δ14CO2的时间变化，合理地再现了观测到的Δ14CO2的分布。夏季δCO2ff变化显著，变化范围在< 5 ~ ~ 100 ppmv之间，6、7、8月δCO2ff变化趋势不显著。δCO2ff水平与大气扩散条件密切相关。δCO2ff的日周期表现为夜间和高峰双峰型，与行星边界层的发育和车辆co2的排放有关。夏季盆地内δCO2ff的空间分布明显高于盆地外，西安市市区最高可达40 ppmv，西安市周边地区最高可达15 ppmv，表明当地化石燃料排放较大。此外，我们发现忽略夏季陆地生物圈异养呼吸的影响会略微低估盆地计算的δCO2ff约0.38 ppmv。
Recent studies on fossil fuel CO2simulation associated with Δ14CO2measurements is quite limited, particularly in China. In this study, the fossil fuel CO2recently added to the atmosphere (δCO2ff) over the Guanzhong basin, central China, during summer 2012 is simulated using a modified WRF-CHEM model constrained by measured CO2mixing ratio and Δ14CO2. The model well captures the temporal variation of observed CO2mixing ratio and Δ14CO2, and reasonably reproduces the distribution of observed Δ14CO2. The simulation shows a significant variation of δCO2ff during summertime, ranging from < 5 ppmv to ~ 100 ppmv and no remarkable trend of δCO2ff is found for June, July, and August. The δCO2ff level is closely associated with atmospheric diffusion conditions. The diurnal cycle of δCO2ff presents a double-peak pattern, a nocturnal one and a rush-hour one, related to the development of planetary boundary layer and CO2emission from vehicles. The spatial distributions of summertime δCO2ff within the basin is clearly higher than the outside, reaching up to 40 ppmv in urban Xi'an and 15 ppmv in its surrounding areas, indicative of large local fossil fuel emissions. Furthermore, we find that neglecting the influence of summer heterotrophic respiration in terrestrial biosphere would slightly underestimate the calculated δCO2ff by about 0.38 ppmv in the basin.