金华市不同区域负氧离子浓度特征与气象环境因素相关分析

利用2019—2021年金华市空气负氧离子浓度和气象环境资料，研究不同区域（平原城区、平原公园、水边景区、山林景区）负氧离子浓度时空分布特征，分析人类活动最多的城区负氧离子浓度与气象环境因素不同时间尺度的相关性，以及不同天空状况的差异。结果表明：负氧离子浓度呈现平原低、山区高的分布特征，植被茂密、动态水流可增加负氧离子浓度和提高浓度等级。山林景区日出和日落前后负氧离子浓度较高，水边景区凌晨和午后出现高值，平原地区则在下午达到高峰。不同区域四季日变化趋势整体较一致，但不同季节负氧离子浓度峰值大小、日较差和出现峰值时刻存在差异。四季不同区域负氧离子浓度有所差异，主要表现为6—9月高，其中尤以8月山林景区为最。负氧离子浓度与气象环境因素的相关性在不同时间尺度上差异较大：时尺度上与气温、风速、雨量和O3呈显著正相关，而与PM2.5呈显著负相关。四季看，负氧离子浓度春季与风速相关性最高，夏季为气温，秋季为O3，冬季为PM2.5。日尺度上则与相对湿度、风速、雨量呈显著正相关，与PM2.5和O3呈显著负相关，且雨天负氧离子浓度明显高于其他天空状况，差异在冬季达最大。

Characteristics of negative air ion concentration in different regions and correlation analysis with meteorological environmental factors of Jinhua City

Using the negative air ion concentration(NAIC) and meteorological and environmental data of Jinhua City from 2019 to 2021, the temporal variation and spatial distribution characteristics of NAIC in different regions (plain urban area, plain park, waterside scenic spot, mountain forest scenic spot) were analyzed in this paper. Besides, focusing on the urban areas with human activities, the correlation between the NAIC and meteorological and environmental factors on different time scales, as well as the differences in different weather conditions were also provided. The results show that the distribution characteristics of NAIC present low plain and high mountain area. Dense vegetation and dynamic water flow can increase the NAIC and improve the concentration level. The NAIC in mountain forest scenic spots is higher before and after sunrise and sunset, while that in waterside scenic spots is higher in the small hours and afternoon, while that in plain areas reaches its peak in the afternoon. The diurnal variation trend of the four seasons in different regions is generally consistent, but there are differences in the peak value, daily range and peak moment of NAIC in different seasons .The seasonal difference of NAIC in different functional zones can be seen in this research, with the maximum in the summer from June to September, especially in August in mountain forest scenic spots. The correlation between NAIC and meteorological environmental factors is quite different on different time scales. on the hour scale, it is significantly positively correlated with temperature, wind speed, rainfall and O3, while it is significantly negatively correlated with PM2.5; In terms of seasons, spring has the highest correlation with wind speed, with temperature in summer, O3 in autumn and PM2.5 in winter; On the day scale, it has a significant positive correlation with relative humidity, wind speed and rainfall, and a significant negative correlation with PM2.5 and O3. In addition, the NAIC on rainy days is significantly higher than other weather conditions, with the difference reaching its maximum in winter.