基于WRF模式的京津冀地区地表大气CO2浓度的模拟研究

在“双碳”目标背景下，从国家层面到地方层面，区域、城市、行业企业都在制定和实施双碳目标行动计划。CO₂模拟因其客观性和高时空分辨率等优势，在城市碳排放研究中深受重视。本研究以京津冀地区为研究区域，采用Picarro仪器高精度观测的2019—2020年CO₂数据，利用WRF模式进行CO₂传输模拟，分析了CO₂浓度变化的季节特征，评估了模式在城区中心、城郊及背景3个观测站点的模拟效果，并对边界层高度及化石燃料碳排放等可能影响CO₂浓度的因素进行了研究。3个观测站点分别为北京中国科学院大气物理研究所325 m气象塔观测站（北京站）、河北香河观测站（香河站）和上甸子区域本底观测站（上甸子站）。模拟结果表明：上甸子站优于香河站，香河站优于北京站，在冬季尤其明显；CO₂浓度的高值区主要分布在城区、电厂和工业区，尤其是唐山、石家庄和邯郸地区，大量交通、工业排放导致CO₂浓度明显上升，且高值区的范围在冬季最大；就日平均变化和日变化而言，边界层高度与CO₂浓度存在相反变化趋势；3个站点的化石燃料碳排放（FFECO2）与近地面总CO₂浓度存在正相关关系，冬春季的相关性高于夏秋季，且FFECO2的占比从大到小依次为北京站、香河站、上甸子站；CO₂传输模拟的不确定性存在空间差异和季节变化。

Simulation of surface atmospheric CO2 concentration in Beijing-Tianjin-Hebei region based on WRF model

Under the background of "dual-carbon" goals, regional, urban and industrial enterprises are formulating and implementing the "dual-carbon" goals action plan from the national level to the local level.Because of its objectivity and high temporal and spatial resolution, CO₂ simulation is deeply valued in the research of urban carbon emission.This paper took Beijing-Tianjin-Hebei region as the research area, used the high-precision CO₂ data observed by Picarro instrument from 2019 to 2020, used WRF model to simulate CO₂ transmission, analyzed the seasonal characteristics of CO₂ concentration change, evaluated the simulation effect of the model in the urban center, suburbs and background stations, and studied the factors that may affect CO₂ concentration, such as planetary boundary layer height and fossil fuel carbon emission.The three observation stations are the 325 m meteorological tower observation station at Institute of Atmospheric Physics, Chinese Academy of Sciences (Beijing station), Hebei Xianghe observation station (Xianghe station) and Shangdianzi regional background observation station (Shangdianzi station).The simulation results show that:The effect of Shangdianzi station is better than that of Xianghe station, and the effect of Xianghe station is better than that of Beijing station, especially in winter.The high value areas of CO₂ concentration are mainly distributed in urban areas, power plants and industrial areas, especially in Tangshan, Shijiazhuang and Handan areas.A large number of traffic and industrial emissions lead to a significant increase in CO₂ concentration, and the range of high value area is the largest in winter.In terms of daily and diurnal variations, there is an opposite trend between the planetary boundary layer height and CO₂ concentration.There is a positive correlation between fossil fuel carbon emissions (FFECO2) and total CO₂ concentration near the surface at the three stations.The correlations in winter and spring are higher than that in summer and autumn, and the proportion of FFECO2 is Beijing station, Xianghe station and Shangdianzi station from large to small.There are spatial differences and seasonal variations in the uncertainty of CO₂ transport simulation.