2020年天津市不同功能区空气负氧离子浓度时空分布及其与气象条件的关系OACSTPCD

Utilizing hourly air negative oxygen ion and meteorological observation data from Tianjin city in 2020,the variations in air negative oxygen ion concentrations(ANOIC)across different seasons and weather conditions within three typical functional areas,i.e.forests,wetlands,and urban zones and their relationships with meteoro-logical elements were investigated.The results indicate that the ANOIC is highest in forests,followed by wetlands,and lowest in urban areas,with the ranking for seasons being summer>spring>autumn>winter.The ANOIC is highest on rainy days and lowest on snowy days.The ANOIC in forests on clear days is slightly higher than on foggy days,whereas those in wetlands and urban areas are slightly lower on clear days compared to foggy days.The diurnal variation of ANOIC is bimodal,with the amplitude of variation following the sequences of forests>wetlands>urban areas,and summer>spring>autumn>winter.Overall,ANOIC shows a positive correlation with temperature,relative humidity,vapor pressure,and the amount of precipitation in the past 24 hours,but a negative correlation with atmospheric pressure.The relationship between ANOIC and visibility differs across the different functional areas,while the correlation with wind speed is not significant.The relationship between ANOIC and me-teorological elements varies across different seasons and weather conditions.In urban areas,the ANOIC is signifi-cantly influenced by human activities,making its variability more complex compared to forests and wetlands,and its correlation with meteorological elements is weaker on the whole.