Analysis and optimal design of air quality monitoring networks using a variational approach

With increasing interest in air pollution, the installation of air quality monitoring networks for regular measurement is considered a very important task in many countries. However, operation of air quality monitoring networks requires much time and money. Therefore, the representativeness of the locations of air quality monitoring networks is an important issue that has been studied by many groups worldwide. Most such studies are based on statistical analysis or the use of geographic information systems (GIS) in existing air quality monitoring network data. These methods are useful for identifying the representativeness of existing measuring networks, but they cannot verify the need to add new monitoring stations. With the development of computer technology, numerical air quality models such as CMAQ have become increasingly important in analyzing and diagnosing air pollution. In this study, PM2.5 distributions in Busan were reproduced with 1-km grid spacing by the CMAQ model. The model results reflected actual PM2.5 changes relatively well. A cluster analysis, which is a statistical method that groups similar objects together, was then applied to the hourly PM2.5 concentration for all grids in the model domain. Similarities and differences between objects can be measured in several ways. K-means clustering uses a non-hierarchical cluster analysis method featuring an advantageously low calculation time for the fast processing of large amounts of data. K-means clustering was highly prevalent in existing studies that grouped air quality data according to the same characteristics. As a result of the cluster analysis, PM2.5 pollution in Busan was successfully divided into groups with the same concentration change characteristics. Finally, the redundancy of the monitoring stations and the need for additional sites were analyzed by comparing the clusters of PM2.5 with the locations of the air quality monitoring networks currently in operation.This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(2017R1D1A3B03036152).

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Proposals for new data quality objectives to underpin ambient air quality monitoring networks

Accreditation and Quality Assurance ◽

10.1007/s00769-014-1085-0 ◽

2014 ◽

Vol 19 (6) ◽

pp. 465-471

Author(s):

Richard J. C. Brown ◽

Peter T. Woods

Keyword(s):

Air Quality ◽

Data Quality ◽

Ambient Air ◽

Quality Monitoring ◽

Air Quality Monitoring ◽

Monitoring Networks ◽

Ambient Air Quality

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A methodology for the quantification of the net African dust load in air quality monitoring networks

Atmospheric Environment ◽

10.1016/j.atmosenv.2007.04.047 ◽

2007 ◽

Vol 41 (26) ◽

pp. 5516-5524 ◽

Cited By ~ 128

Author(s):

M. Escudero ◽

X. Querol ◽

J. Pey ◽

A. Alastuey ◽

N. Pérez ◽

...

Keyword(s):

Air Quality ◽

Quality Monitoring ◽

Air Quality Monitoring ◽

Monitoring Networks ◽

African Dust ◽

Dust Load

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Optimization of Air Quality Monitoring Networks in Busan Using a GIS-based Decision Support System

Journal of Korean Society for Atmospheric Environment ◽

10.5572/kosae.2007.23.5.526 ◽

2007 ◽

Vol 23 (5) ◽

pp. 526-538 ◽

Cited By ~ 5

Author(s):

Eun-Chul Yoo ◽

Ok-Hyun Park

Keyword(s):

Decision Support ◽

Air Quality ◽

Decision Support System ◽

Support System ◽

Quality Monitoring ◽

Air Quality Monitoring ◽

Monitoring Networks

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Gridded global surface ozone metrics for atmospheric chemistry model evaluation

Earth System Science Data Discussions ◽

10.5194/essdd-8-603-2015 ◽

2015 ◽

Vol 8 (2) ◽

pp. 603-647 ◽

Cited By ~ 1

Author(s):

E. D. Sofen ◽

D. Bowdalo ◽

M. J. Evans ◽

F. Apadula ◽

P. Bonasoni ◽

...

Keyword(s):

Air Quality ◽

Atmospheric Chemistry ◽

Model Evaluation ◽

Climate Model ◽

Surface Ozone ◽

Quality Monitoring ◽

Air Quality Monitoring ◽

Monitoring Networks ◽

Chemistry Research ◽

Consistent Manner

Abstract. The concentration of ozone at the Earth's surface is measured at many locations across the globe for the purposes of air quality monitoring and atmospheric chemistry research. We have brought together all publicly available surface ozone observations from online databases from the modern era to build a consistent dataset for the evaluation of chemical transport and chemistry-climate (Earth System) models for projects such as the Chemistry-Climate Model Initiative and Aer-Chem-MIP. From a total dataset of approximately 6600 sites and 500 million hourly observations from 1971–2015, approximately 2200 sites and 200 million hourly observations pass screening as high-quality sites in regional background locations that are appropriate for use in global model evaluation. There is generally good data volume since the start of air quality monitoring networks in 1990 through 2013. Ozone observations are biased heavily toward North America and Europe with sparse coverage over the rest of the globe. This dataset is made available for the purposes of model evaluation as a set of gridded metrics intended to describe the distribution of ozone concentrations on monthly and annual timescales. Metrics include the moments of the distribution, percentiles, maximum daily eight-hour average (MDA8), SOMO35, AOT40, and metrics related to air quality regulatory thresholds. Gridded datasets are stored as netCDF-4 files and are available to download from the British Atmospheric Data Centre (doi:10.5285/08fbe63d-fa6d-4a7a-b952-5932e3ab0452). We provide recommendations to the ozone measurement community regarding improving metadata reporting to simplify ongoing and future efforts in working with ozone data from disparate networks in a consistent manner.

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Design of an ozone and nitrogen dioxide sensor unit and its long-term operation within a sensor network in the city of Zurich

10.5194/amt-2017-22 ◽

2017 ◽

Cited By ~ 1

Author(s):

Michael Mueller ◽

Jonas Meyer ◽

Christoph Hueglin

Keyword(s):

Air Quality ◽

Sensor Network ◽

Data Transfer ◽

Low Cost ◽

Effective Procedure ◽

Quality Monitoring ◽

Air Quality Monitoring ◽

Monitoring Networks ◽

Term Operation ◽

Diffusion Tubes

Abstract. This study focuses on the investigation and quantification of low-cost sensor performance in application fields such as the extension of traditional air quality monitoring networks or the replacement of diffusion tubes. For this, sensor units consisting of two boxes featuring NO2 and O3 low-cost sensors and wireless data transfer were engineered. The sensor units were initially operated at air quality monitoring sites for three months for performance analysis and initial calibration. Afterwards, they were relocated and operated within a sensor network consisting of six locations for more than one year. Our analyses show that the employed O3 and NO2 sensors can be accurate to 2–5 and 5–7 ppb, respectively, during the first three months of operation. This accuracy, however, could not be maintained during their operation within the sensor network related to changes in sensor behaviour. Hence, the low-cost sensors in our configuration do not reach the accuracy level of NO2 diffusion tubes. Tests in the laboratory revealed that changes in relative humidity can impact the signal of the employed NO2 sensors similarly as changes in ambient NO2 concentration. All the employed low-cost sensors need to be individually calibrated. Best performance of NO2 sensors is achieved when the calibration models include also time dependent parameters accounting for changes in sensor response over time. Accordingly, an effective procedure for continuous data control and correction is essential for obtaining meaningful data. It is demonstrated that linking the measurements from low-cost sensors to the high quality measurements from routine air quality monitoring stations is an effective procedure for both tasks provided that time periods can be identified when pollutant concentrations can be accurately predicted at sensor locations.

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