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Abstract
As an air pollution phenomenon, haze has become one of the focuses of social discussion. Research into the causes and concentration prediction of haze is significant, forming the basis of haze prevention. The inversion of Aerosol Optical Depth (AOD) based on remote sensing satellite imagery can provide a reference for the concentration of major pollutants in a haze, such as PM2.5 concentration and PM10 concentration. This paper used satellite imagery to study haze problems and chose PM2.5, one of the primary haze pollutants, as the research object. First, we used conventional methods to perform the inversion of AOD on remote sensing images, verifying the correlation between AOD and PM2.5. Subsequently, to simplify the parameter complexity of the traditional inversion method, we proposed using the convolutional neural network instead of the traditional inversion method and constructing a haze level prediction model. Compared with traditional aerosol depth inversion, we found that convolutional neural networks can provide a higher correlation between PM2.5 concentration and satellite imagery through a more simplified satellite image processing process. Thus, it offers the possibility of researching and managing haze problems based on neural networks.
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Heshmatol Vaezin SM, Juybari MM, Daei A, Avatefi Hemmat M, Shirvany A, Tallis MJ, Hirabayashi S, Moeinaddini M, Hamidian AH, Sadeghi SMM, Pypker TG. The effectiveness of urban trees in reducing airborne particulate matter by dry deposition in Tehran, Iran. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:842. [PMID: 34821985 DOI: 10.1007/s10661-021-09616-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/12/2021] [Indexed: 06/13/2023]
Abstract
Deposition of atmospheric pollution as particulate matter (PM) has become a serious issue in many urban areas. This study measured and estimated the amount of atmospheric PM deposition onto oriental plane (Platanus orientalis L.) trees located in Tehran Megapolis, Iran. PM deposited on the leaves of urban trees during spring and summer was estimated using leaf wash measurements. In addition to direct measurements, the dry deposition velocity and the yearly whole-tree PM deposition were estimated using both field measurements and a theoretical model of deposition flux. We estimated air quality improvement as a result of the trees at respiratory height (1.5 m), tree height (10 m), and boundary layer height (1719 m). Foliar PM deposition during spring and summer was estimated to average 0.05 g/leaf and 41.39 g/tree using direct measurements. The annual PM deposited on the leaves, trunk, and branches of an average urban tree was calculated to be 78.60 g/tree. Trees were estimated to improve air quality at 1.5 m, 10 m, and 1719 m from ground level by 25.8%, 5.8%, and 0.1%, respectively. Hence, oriental plane trees substantially reduce PM at respiratory height.
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Affiliation(s)
| | | | - Arash Daei
- Department of Forestry and Forest Economics, University of Tehran, Karaj, Iran
| | | | | | - Matthew James Tallis
- University Centre Sparsholt (incorporating Andover College Campus), Sparsholt College Hampshire, Sparsholt, Winchester, SO21 2NF, UK
| | - Satoshi Hirabayashi
- The Davey Institute, The Davey Tree Expert Company, 1 Forestry Drive, Syracuse, NY, USA
| | | | | | - Seyed Mohammad Moein Sadeghi
- Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Faculty of Silviculture and Forest Engineering, Transilvania University of Brasov, Şirul Beethoven 1, Brasov, 500123, Romania
- School of Forest Fisheries, and Geomatics Sciences, Newins-Ziegler Hall, University of Florida, Gainesville, FL, USA
| | - Thomas Grant Pypker
- Department of Natural Resource Science, Thompson Rivers University, Kamloops, BC, V2C 0C8, Canada
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Chen Z, Schofield R, Rayner P, Zhang T, Liu C, Vincent C, Fiddes S, Ryan RG, Alroe J, Ristovski ZD, Humphries RS, Keywood MD, Ward J, Paton-Walsh C, Naylor T, Shu X. Characterization of aerosols over the Great Barrier Reef: The influence of transported continental sources. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 690:426-437. [PMID: 31299575 DOI: 10.1016/j.scitotenv.2019.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/29/2019] [Accepted: 07/01/2019] [Indexed: 06/10/2023]
Abstract
The rapid environmental changes in Australia prompt a more thorough investigation of the influence of transportation, local emissions, and optical-chemical properties on aerosol production across the region. A month-long intensive measurement campaign was conducted during spring 2016 at Mission Beach, a remote coastal site west of the Great Barrier Reef (GBR) on the north-east coast of Australia. One aerosol pollution episode was investigated in early October. This event was governed by meteorological conditions and characterized by the increase in black carbon (BC) mass concentration (averaged value of 0.35 ± 0.20 μg m-3). Under the influence of the continental transportation, a new layer of nucleation-mode aerosols with an initial size diameter of 20 nm was observed and aerosol number concentrations reached the peak of 6733 cm-3 at a diameter of 29 nm. The averaged aerosol extinction coefficient at the height of 2 km was 150 Mm-1, with a small depolarized ratio (3.5-5%). Simultaneously, the boundary layer height presented a fall-rise trend in the presence of these enhanced aerosol concentrations and became stable in a later stage of the episode. We did not observe clear boundary layer height diurnal variations from the LiDAR observations or from the Weather Research and Forecasting (WRF) model outputs, except in an earlier stage of the aerosol episode for the former. Although the sea breeze may have been responsible for these particles, on the balance of available data, we suggest that the aerosol properties at the GBR surface during this period are more likely influenced by regional transportation of continental sources, including biomass-burning aerosols.
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Affiliation(s)
- Zhenyi Chen
- Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 230031 Hefei, China
| | - Robyn Schofield
- School of Earth Sciences, University of Melbourne, 3010 Melbourne, VIC, Australia
| | - Peter Rayner
- School of Earth Sciences, University of Melbourne, 3010 Melbourne, VIC, Australia
| | - Tianshu Zhang
- Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 230031 Hefei, China
| | - Cheng Liu
- Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 230031 Hefei, China; School of Earth and Space Sciences, University of Science and Technology of China, 230026 Hefei, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Claire Vincent
- School of Earth Sciences, University of Melbourne, 3010 Melbourne, VIC, Australia
| | - Sonya Fiddes
- School of Earth Sciences, University of Melbourne, 3010 Melbourne, VIC, Australia
| | - Robert George Ryan
- School of Earth Sciences, University of Melbourne, 3010 Melbourne, VIC, Australia
| | - Joel Alroe
- International Laboratory for Air Quality and Health, Queensland University of Technology, QLD 4000, Australia
| | - Zoran D Ristovski
- International Laboratory for Air Quality and Health, Queensland University of Technology, QLD 4000, Australia
| | - Ruhi S Humphries
- Climate Science Centre, Oceans and Atmosphere, CSIRO, 3195 Aspendale, VIC, Australia
| | - Melita D Keywood
- Climate Science Centre, Oceans and Atmosphere, CSIRO, 3195 Aspendale, VIC, Australia
| | - Jason Ward
- Climate Science Centre, Oceans and Atmosphere, CSIRO, 3195 Aspendale, VIC, Australia
| | | | - Travis Naylor
- School of Chemistry, University of Wollongong, 2522, NSW, Australia
| | - Xiaowen Shu
- Key Lab of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 230031 Hefei, China
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Yuan CS, Lu CC, Shen HZ, Li TC. Metallic characteristics of PM 2.5 and PM 2.5-10 for clustered Aeolian Dust Episodes occurred in an extensive fluvial basin during rainy season. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2018; 68:1085-1102. [PMID: 29701507 DOI: 10.1080/10962247.2018.1469554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 06/08/2023]
Abstract
UNLABELLED Aeolian dust episodes (ADEs) have been an emergency disaster in the Kaoping River Valley during the rainy season (May-September), which can severely deteriorate ambient particulate air quality in the region surrounding the Kaoping River. Thus, this study aims to characterize the metallic fingerprint of Aeolian dust (AD) and investigate the effects of ADEs on ambient particulate air quality along the Kaoping River Valley. Four manual sampling sites adjacent to the riverside were selected to collect fine (PM2.5) and coarse (PM2.5-10) aerosol samples during and after the ADEs in the periods of six events. A total of 13 metallic elements were analyzed using an inductively coupled plasma-atomic emission spectrometer. With metallic elements analysis and nonparametric statistical methods of Wilcoxon rank-sum test and Kruskal-Wallis test, this study successfully derived the metallic indicators of ADEs. The mass ratios of crustal elements (Fe, Ca, or Al) to reference element (Cd) obtained during the ADEs were much higher than those obtained after the ADEs. High mass ratios of Fe/Cd, Ca/Cd, and Al/Cd in PM2.5-10 were observed on the influenced areas of ADEs. Among them, (Fe/Cd)2.5-10 was proven as the best indicator which can be applied to effectively validate the existence of ADEs and evaluate their influences on ambient air quality. Moreover, PM2.5 concentrations during the ADEs were 3-3.6 fold higher than those after the ADEs. PM2.5 should be a contributor to AD, even though the mass ratios of PM2.5/PM10 ranged from 0.05 to 0.20 during the ADEs. Our findings provide valuable information regarding the characteristics of the AD during the ADEs in the Kaoping River. IMPLICATIONS Indicators of (Fe/Cd)2.5-10 are approximately applied to observe the effects of ADEs. Local governments could realize the mechanisms of S- and NW-type aeolian dust episodes (ADEs). They can cause deterioration in different ways for the regional air quality surrounding Kaoping River Valley. Residents who have been living in the influenced areas can take precautions to prevent damage from aeolian dust. Strategies for curbing ADEs must reduce the area of bare lands by artificial measures in the long period of the sunny days during the rainy season. Future research should examine physical conditions of topsoils and other chemical composition in aeolian dust.
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Affiliation(s)
- Chung-Shin Yuan
- a Institute of Environmental Engineering , National Sun Yat-Sen University , Kaohsiung , Taiwan, Republic of China
| | - Chun-Chung Lu
- a Institute of Environmental Engineering , National Sun Yat-Sen University , Kaohsiung , Taiwan, Republic of China
| | - Hua-Zhen Shen
- a Institute of Environmental Engineering , National Sun Yat-Sen University , Kaohsiung , Taiwan, Republic of China
| | - Tsung-Chang Li
- a Institute of Environmental Engineering , National Sun Yat-Sen University , Kaohsiung , Taiwan, Republic of China
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