title: A cluster analysis of constant ambient air monitoring data from the Kanto region of Japan.
abstract: This study demonstrates an application of cluster analysis to constant ambient air monitoring data of four pollutants in the Kanto region: NOx, photochemical oxidant (Ox), suspended particulate matter, and non-methane hydrocarbons. Constant ambient air monitoring can provide important information about the surrounding atmospheric pollution. However, at the same time, ambient air monitoring can place a significant financial burden on some autonomous communities. Thus, it has been necessary to reduce both the number of monitoring stations and the number of chemicals monitored. To achieve this, it is necessary to identify those monitoring stations and pollutants that are least significant, while minimizing the loss of data quality and mitigating the effects on the determination of any spatial and temporal trends of the pollutants. Through employing cluster analysis, it was established that the ambient monitoring stations in the Kanto region could be clustered topologically for NOx and Ox into eight groups. From the results of this analysis, it was possible to identify the similarities in site characteristics and pollutant behaviors.
authors.affiliation: Research Center for Sustainable Science and Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan. iizuka@tagen.tohoku.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iizuka
authors.affiliation: Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan. shintaro_shirato@yy.k.u-tokyo.ac.jp.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Shirato
authors.affiliation: Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan. mizukoshi@med.kindai.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mizukoshi
authors.affiliation: Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan. miyuki_noguchi@yy.k.u-tokyo.ac.jp.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Noguchi
authors.affiliation: Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan. akihiro@st.seikei.ac.jp.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yamasaki
authors.affiliation: Department of Environmental Systems, Institute of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan. yukio@k.u-tokyo.ac.jp.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yanagisawa
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016000:Cluster Analysis; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data*; D006838:Hydrocarbons / Q000032:analysis; D007564:Japan; D009589:Nitrogen Oxides / Q000032:analysis; D010126:Ozone / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis
chemical_list: D000393:Air Pollutants; D006838:Hydrocarbons; D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions; D010126:Ozone