济源南山林场不同季节空气负氧离子浓度特征及影响因素OA

This study investigates the spatiotemporal variation characteristics of negative air ion(NAI)concentration and the primary factors influencing it across different seasons using Jiyuan Nanshan Forest as the research site.Based on continuous observations conducted from June 2021 to May 2022 using RR-9411A monitoring equipment and data obtained from an automatic weather station,this study analyzes the diurnal and seasonal variations in NAI concentration and its correlation with environmental factors.Results show that the order of seasonal average NAI concentrations is autumn(889 ion·cm-3)＞summer(756 ion·cm-3)＞winter(601 ion·cm-3)＞spring(430 ion·cm-3).The diurnal variation patterns reveal that(ⅰ)in autumn,peak NAI concentration in appears at 11:00(1 030 ion·cm-3);(ⅱ)in summer,a"double-peak and double-valley"pattern is observed;(ⅲ)in winter,the peak lags behind noon;and(ⅳ)in spring,fluctuations are minimal.Correlation analysis reveals significant seasonal differences in the relationships between NAI concentration and environmental factors,namely,wind speed,temperature,relative humidity,and particulate matter(PM)—specifically,PM with a diameter of ≤ 10 um and PM with a diameter of ≤2.5 um.In spring,the NAI concentration is primarily influenced by wind speed and humidity.Moreover,in summer,it is positively correlated with temperature and wind speed,and in winter,it is significantly correlated with PM levels and relative humidity.Furthermore,vegetation photosynthesis intensity,meteorological conditions(e.g.,precipitation and inversion layer),and human activities are found to be the key drivers of the seasonal differentiation in NAI.This study provides a scientific basis for optimizing forest ecological management and improving air quality assessments.