[Spatiotemporal distribution of negative air ion concentration in urban area and related affecting factors: a review].
Negative air ion (NAI) concentration is an important indicator comprehensively reflecting air quality, and has significance to human beings living environment. This paper summarized the spatiotemporal distribution features of urban NAI concentration, and discussed the causes of these features based on the characteristics of the environmental factors in urban area and their effects on the physical and chemical processes of NAI. The temporal distribution of NAI concentration is mainly controlled by the periodic variation of solar radiation, while the spatial distribution of NAI concentration along the urban-rural gradient is mainly affected by the urban aerosol distribution, underlying surface characters, and urban heat island effect. The high NAI concentration in urban green area is related to the vegetation life activities and soil radiation, while the higher NAI concentration near the water environment is attributed to the water molecules that participate in the generation of NAI through a variety of ways. The other environmental factors can also affect the generation, life span, component, translocation, and distribution of NAI to some extent. To increase the urban green space and atmospheric humidity and to maintain the soil natural attributes of underlying surface could be the effective ways to increase the urban NAI concentration and improve the urban air quality.
Cultivation Base of State Key Laboratory of Humid Subtropical Mountain Ecology, Fuzhou 350007, China. hxh010704@qq.com
Xiang-Hua
XH
Huang
Jian
J
Wang
Hong-Da
HD
Zeng
Guang-Shui
GS
Chen
Xian-Fang
XF
Zhong
D000388:Air / Q000032:analysis*; D000390:Air Ionization; D000838:Anions / Q000032:analysis*; D002681:China; D002947:Cities; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D062211:Spatio-Temporal Analysis
D000838:Anions