Analysis of time variation characteristics of CO2 mass concentration and flux in urban green space

doi:10.3969/j.issn.1673-6141.2025.06.004

Abstract

Abstract: In recent years, climatic and environmental problems such as global warming have attracted more and more attention. Cities are the main emission source of CO2, therefore monitoring the mass concentration and flux of urban CO2 and analyzing of their characteristics are of great significance in the study of global warming and greenhouse gas monitoring. Based on the eddy covariance method, the flux observation of urban green space environment was carried out at the meteorological tower of the East Campus of University of Science and Technology of China (USTC) from July 2017 to July 2021, and the diurnal variation characteristics and influencing factors of CO2 mass concentration and flux near the observation site were mainly studied. The results show that during the observation period, the CO2 mass concentration near USTC campus showed a slight increasing trend, with an average annual increase rate of 4.47 (mg∙m-3 )/a. All of CO2 mass concentration and its daily peak time and valley time showed obvious seasonal characteristics, as well as CO2 flux and its daily valley time. However, the variation trend of the daily peak time of CO2 flux did not have obvious seasonal characteristics, but showed a significant correlation with human commuting time. It can be concluded that the change of CO2 near the campus of USTC was closely related to natural vegetation and human activities.

Key words: urban green space, CO2 mass concentration, CO2 flux, daily variation, peak and valley time

CLC Number:

P416

CHEN Yuemeng , HUA Jiajia , LI Zhuoyuan , SUN Lijun , YUAN Renmin . Analysis of time variation characteristics of CO2 mass concentration and flux in urban green space[J]. Journal of Atmospheric and Environmental Optics, 2025, 20(6): 726-738.

References

[1] 王跃思, 王长科, 刘广仁等.北京大气CO2浓度日变化、季变化及长期趋势[J]. [J].科学通报, 2002, 14:1108-1112 [2]Wigley T, Jones P D.Detecting CO2-induced climatic change [J].Nature, 1981, 292(5820):205-208 [3] Houghton J.The IPCC report 2001[C]. 1st Solar and Space Weather Euroconference on the Solar Cycle and Terrestrial Climate, 2000: 255-259. [4]Gu L H, Baldocchi D.Fluxnet 2000 synthesis-Foreword [J].Agricultural and Forest Meteorology, 2002, 113(1-4):1-2 [5] Yu G R, Wen X F, Sun X M, et al.Overview of ChinaFLUX and evaluation of its eddy covariance measurement[J], Agricultural and Forest Meteorology, 2006, 137:125-137. DOI:10.1016/j.agrformet.2006.02.011. [6]He H L, Liu M, Sun X M, et al.Uncertainty analysis of eddy flux measurements in typical ecosystems of ChinaFLUX [J].Ecological Informatics, 2010, 5(06):492-502 [7]Sun X M, Zhu Z L, Wen X F, et al.The impact of averaging period on eddy fluxes observed at ChinaFLUX sites [J].Agricultural and Forest Meteorology, 2006, 137(3-4):188-193 [8] Chang X Q, Xing Y Q, Gong W S, et al.Evaluating gross primary productivity over 9 ChinaFlux sites based on ran- dom forest regression models[J]. Science of the Total Environment, 2023, 875. DOI: 10.1016/j.scitotenv.2023.162601. [9]Liu Z J, Wang L C, Wang S S.Comparison of Different GPP Models in China Using MODIS Image and ChinaFLUX Data [J].Remote Sensing, 2014, 6(10):10215-10231 [10]Leuning R, Yu G R.Carbon exchange research in ChinaFLUX – Preface [J].Agricultural and Forest Meteorology, 2006, 137(3-4):124-124 [11] Li Z Q, Yu G R, Wen X F, et al.Energy balance closure at ChinaFLUX sites[J]. Science in China Series D-Earth Sciences, 2005, 48:51-62. DOI: 10.1360/05zd0005. [12] Liu M, Fu Y L, Yang F.Research progress on urban carbon fluxes based on eddy covariance technique[J]. Chinese Journal of Applied Ecology，Feb． 2014，25( 2) : 611－619. [13]刘敏, 伏玉玲, 杨芳.基于涡度相关技术的城市碳通量研究进展 [J].应用生态学报, 2014, 25(02):611-619 [14] United Nations, Department of Economic and Social Affairs Population Division[J].Population and Development Review, 2015, 41(3):555-555. [15]UN: World urbanization prospects：the 2014 revision, New York, 2015. [16]Schmutz M, Vogt R, Feigenwinter C, et al.Ten years of eddy covariance measurements in Basel,Switzerland: Seasonal and interannual variabilities of urban CO2 mole fraction and flux [J].Journal of Geophysical Research-Atmospheres, 2016, 121(14):8649-8667 [17]Liu X M, Cheng X L, Hu F.Gradient characteristics of CO2 concentration and flux in Beijing urban area part I: Concentration and virtual temperature [J].Chinese Journal of Geopysics, 2015, 58(05):15021512- [18]刘晓曼, 程雪玲, 胡非.北京城区二氧化碳浓度和通量的梯度变化特征——浓度与虚温 [J].地球物理学报, 2015, 58(05):1502-1512 [19]Zhi X, Ao X Y.Study of carbon dioxide flux characteristics over central urban area in Shanghai [J].Journal of Meteorology and Environment, 2020, 36(3):72- [20]支星, 敖翔宇.上海中心城区二氧化碳通量特征分析 [J].气象与环境学报, 2020, 36(03):72-79 [21] Xu Z W, Xiao R B, Deng Y R, et al.Carbon dioxide emission from urban wetland of the Haizhu Lake[J]. Chin J Appl Environ Biol 2016，22 ( 1 ) : 0013-0019. [22]徐志伟, 肖荣波, 邓一荣等.广州海珠湖城市湿地通量特征 [J].应用与环境生物学报, 2016, 22(01):13-19 [23]Lietzke B, Vogt R, Feigenwinter C, et al.On the controlling factors for the variability of carbon dioxide flux in a heterogeneous urban environment [J].International Journal of Climatology, 2015, 35(13):3921-3941 [24]Mei X Y, Shi L J, Zhang W G, et al.Characteristics of CO2 emission fluxes and its influencing factors in urban lawn in Shanghai,China [J].Resources and Environment in the Yangtze Basin, 2011, 20(04):433-438 [25]梅雪英, 史利江, 张卫国, 等.上海城市草坪排放通量特征及其影响因子 [J].长江流域资源与环境, 2011, 20(04):433-438 [26] Grimmond C S B, King T S, Cropley F D, et al.Local-scale fluxes of carbon dioxide in urban environments: methodological challenges and results from Chicago[J]. Environmental Pollution, 2001, 116:S243-S254. DOI:10.1016/s0269-7491(01)00256-1. [27] Zou J, Sun J N, Guo W D, et al.2023.Measurements of CO2 flux over urban， suburban and rural surfaces in Yangtze River Delta region of China［J］.Acta Scientiae Circumstantiae，43（3）：281-292. [28]邹钧, 孙鉴泞, 郭维栋等.长江三角洲地区城市、郊区和乡村下垫面的通量观测 [J].环境科学学报, 2023, 43(03):281-292 [29] Liu Y, Liu H Z, Du Q, et al.Multi-level CO2 fluxes over Beijing megacity with the eddy covariance method[J].Atmospheric and Oceanic Science Letters, 2021, 14(6). DOI:10.1016/j.aosl.2021.100079. [30]Zhang L H, Tong C, Zeng C S.Diurnal and Seasonal Variations of Surface Atmospheric CO2 Concentration in the River Estuarine Marsh [J].Environmental Science, 2014, 35(03):879-884 [31]张林海, 仝川, 曾从盛.河口湿地近地面大气浓度日变化和季节变化 [J].环境科学, 2014, 35(03):879-884 [32]Yuan R M, Kang M, Park S B, et al.Expansion of the planar-fit method to estimate flux over complex terrain [J].Meteorology and Atmospheric Physics, 2011, 110(3-4):123-133 [33]Idso S B, Idso C D, Balling R C.Seasonal and diurnal variations of near-surface atmospheric CO2 concentration within a residential sector of the urban CO2 dome of Phoenix,AZ,USA [J].Atmospheric Environment, 2002, 36(10):1655-1660 [34] He W, Liu H Z, Feng J W.Characteristics of turbulent fluxes and carbon dioxide flux over urban surface layer [J]．Climatic and Environmental Research (in Chinese), 15 （1）：21-33． [35]何文, 刘辉志, 冯健武.城市近地层湍流通量及通量变化特征 [J].气候与环境研究, 2010, 15(01):21-33 [36] Grimmond C S B, Salmond J A, Oke T R, et al.Flux and turbulence measurements at a densely built-up site in Marseille: Heat, mass (water and carbon dioxide), and momentum[J]. Journal of Geophysical Research-Atmospheres, 2004, 109(D24). DOI:10.1029/2004jd004936. [37] Liu H.Experimental study on aerosol fluctuation characteristics and flux measurement in urban surface layer. University of Science and Technology of China, 2019. [38]刘豪.城市近地面层气溶胶浓度起伏特征及通量测量的实验研究[D]. 中国科学技术大学，2019. [39] 于贵瑞，孙晓敏，等.陆地生态系统通量观测的原理与方法[M]. 第二版. 北京：高等教育出版社，2017 : 187-225. [40]Zhu Z L, Sun X M, Wen X F, et al.Study on the processing method of nighttime CO2 eddy covariance flux data in ChinaFLUX [J].Science in China (Series D: Earth Sciences), 2006, 49(S2):36-46 [41] 王庚辰，孔琴心，任丽新，等.中国大陆上空CO2的本底浓度及其变化[J]. 科学通报，2002(10) : 780-783. [42]Renyang Q Q, Lian Y, Li H X, et al.Spatial and temporal distribution of CO2 concentration in mainland China and its influencing factors [J].China Environmental Science, 2023, 43(4):1919-1929 [43]任杨千千, 连懿, 李海笑等.中国大陆浓度时空分布特征及驱动因素 [J].中国环境科学, 2023, 43(04):1919-1929