scholarly journals A Movable Fog-Haze Boundary Layer Conceptual Model Over Jianghuai Area, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Duanyang Liu ◽  
Wenlian Yan ◽  
Junlong Qian ◽  
Mei Liu ◽  
Zida Wang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Air Quality ◽  
Conceptual Model ◽  
North China ◽  
Air Mass ◽  
Cold Air ◽  
Movable Boundary ◽  
Winter Half ◽  
Local Emissions

The Jianghuai area is an “important” region not only for its local pollutant accumulation but the belt for pollutant transportation between North China and the Yangtze River Delta during the winter half of the year (often from October to next February). In this study, a movable boundary layer conceptual model for the Jianghuai area in the winter half of the year is established based on the analyses of characteristics of atmospheric circulations and boundary layer dynamic conditions. This conceptual model can well explain the causes of air quality change and frequent fog-haze episodes. Variations of the intensity and range of the cold and warm fronts in the Jianghuai area in the winter half of the year lead to form a movable boundary in this area. When the southerly wind is strong, or affected by strong cold air mass, the air quality in the Jianghuai area may be excellent with a low air pollution index; Two atmospheric circulations provide favorable conditions for the fog-haze formation and maintenance in Jianghuai area: 1) When the shallow weak cold air mass is below the deep moist warm air mass, a stable temperature inversion occurs. The pollutants are transported to the Jianghuai area by the weak cold air mass, and local emissions also accumulate. As a result, a severe air pollution episode appears. 2) When the northerly cold air mass is as intense as the southerly moist warm air mass, the pollutants transported from North China as well as local emissions will continuously accumulate in the study area, which may lead to more severe air pollution. This conceptual model can help us analyze atmospheric diffusion capacity, and benefit the forecast and early warning of airflow stagnation area and fog-haze episode.

scholarly journals Profiling of Dust and Urban Haze Mass Concentrations during the 2019 National Day Parade in Beijing by Polarization Raman Lidar

2021 ◽  
Vol 13 (16) ◽  
pp. 3326
Author(s):  
Zhuang Wang ◽  
Cheng Liu ◽  
Yunsheng Dong ◽  
Qihou Hu ◽  
Ting Liu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
North China Plain ◽  
North China ◽  
Raman Lidar ◽  
Relative Contribution ◽  
Lidar Ratio ◽  
Local Emissions ◽  
532 Nm ◽  
Mass Concentrations

The polarization–Raman Lidar combined sun photometer is a powerful method for separating dust and urban haze backscatter, extinction, and mass concentrations. The observation was performed in Beijing during the 2019 National Day parade, the particle depolarization ratio at 532 nm and Lidar ratio at 355 nm are 0.13 ± 0.05 and 52 ± 9 sr, respectively. It is the typical value of a mixture of dust and urban haze. Here we quantify the contributions of cross-regional transported natural dust and urban haze mass concentrations to Beijing’s air quality. There is a significant correlation between urban haze mass concentrations and surface PM2.5 (R = 0.74, p < 0.01). The contributions of local emissions to air pollution during the 2019 National Day parade were insignificant, mainly affected by regional transport, including urban haze in North China plain and Guanzhong Plain (Hebei, Tianjin, Shandong, and Shanxi), and dust aerosol in Mongolia regions and Xinjiang. Moreover, the trans-regional transmission of natural dust dominated the air pollution during the 2019 National Day parade, with a relative contribution to particulate matter mass concentrations exceeding 74% below 4 km. Our results highlight that controlling anthropogenic emissions over regional scales and focusing on the effects of natural dust is crucial and effective to improve Beijing’s air quality.

scholarly journals Relationships between the planetary boundary layer height and surface pollutants derived from lidar observations over China

2018 ◽  
Author(s):  
Tianning Su ◽  
Zhanqing Li ◽  
Ralph Kahn
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Negative Correlation ◽  
North China Plain ◽  
North China ◽  
Planetary Boundary Layer Height ◽  
Layer Height ◽  
Boundary Layer Height ◽  
The North ◽  
The North China Plain

Abstract. The frequent occurrence of severe air pollution episodes in China has raised great concerns with the public and scientific communities. Planetary boundary layer height (PBLH) is a key factor in the vertical mixing and dilution of near-surface pollutants. However, the relationship between PBLH and surface pollutants, especially particulate matter (PM) concentration, across the whole of China, is not yet well understood. We investigate this issue at ~ 1500 surface stations using PBLH derived from space-borne and ground-based lidar, and discuss the influence of topography and meteorological variables on the PBLH-PM relationship. A generally negative correlation is observed between PM and the PBLH, albeit varying greatly in magnitude with location and season. Correlations are much weaker over the highlands than plains regions, which may be associated with lower pollution levels and mountain breezes. The influence of horizontal transport on surface PM is considered as well, manifested as a negative correlation between surface PM and wind speed over the whole nation. Strong wind with clean upwind sources plays a dominant role in removing pollutants, and leads to weak PBLH-PM correlation. A ventilation rate is introduced to jointly consider horizontal and vertical dispersion, which has the largest impact on surface pollutant accumulation over the North China Plain. Aerosol absorption feedbacks also appear to affect the PBLH-PM relationship, as revealed via comparing air pollution in Beijing and Hong Kong. Absorbing aerosols in high concentrations likely contribute to the significant PBLH-PM correlation over the North China Plain (e.g., during winter). As major precursor emissions for secondary aerosols, sulfur dioxide, nitrogen dioxide, and carbon monoxide have similar negative responses to increased PBLH, whereas ozone is positively correlated with PBLH over most regions, which may be caused by heterogeneous reactions and photolysis rates.

scholarly journals Insights into particulate matter pollution in the North China Plain during wintertime: Local contribution or regional transport?

2020 ◽  
Author(s):  
Jiarui Wu ◽  
Naifang Bei ◽  
Yuan Wang ◽  
Xia Li ◽  
Suixin Liu ◽  
...  
Keyword(s):  
Air Quality ◽  
Source Apportionment ◽  
North China Plain ◽  
North China ◽  
Regional Transport ◽  
The North ◽  
The North China Plain ◽  
Haze Event ◽  
Non Local ◽  
Local Emissions

Abstract. Accurate identification and quantitative source apportionment of fine particulate matters (PM2.5) provide an important prerequisite for design and implementation of emission control strategies to reduce PM pollution. Therefore, a source-oriented version of the WRF-Chem model is developed in the study to make source apportionment of PM2.5 in the North China Plain (NCP). A persistent and heavy haze event occurred in the NCP from 05 December 2015 to 04 January 2016 is simulated using the model as a case study to quantify PM2.5 contributions of local emissions and regional transport. Results show that local and non-local emissions contribute 36.3 % and 63.7 % of the PM2.5 mass in Beijing during the haze event on average. When Beijing's air quality is excellent or good in terms of hourly PM2.5 concentrations, local emissions dominate the PM2.5 mass with contributions exceeding 50 %. However, when the air quality is severely polluted, the PM2.5 contribution of non-local emissions is around 75 %. The non-local emissions also dominate the Tianjin's air quality, with average PM2.5 contributions exceeding 70 %. The PM2.5 level in Hebei and Shandong is generally controlled by local emissions, but in Henan, local and non-local emissions play an almost equivalent role in the PM2.5 level, except when the air quality is severely polluted, with non-local PM2.5 contributions of over 60 %. Additionally, the primary aerosol species are generally dominated by local emissions with the average contribution exceeding 50%. However, the source apportionment of secondary aerosols shows more evident regional characteristics. Therefore, except cooperation with neighboring provinces to carry out strict emission mitigation measures, reducing primary aerosols constitutes the priority to alleviate PM pollution in the NCP, especially in Beijing and Tianjin.

Changes of air pollutants’ concentrations in selected Romanian cities during the pandemic year 2020

2021 ◽  
Author(s):  
Gabriela Iorga ◽  
George-Bogdan Burghelea
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
European Commission ◽  
Air Pollutants ◽  
Meteorological Parameters ◽  
Dust Particles ◽  
Spatial And Temporal Variation ◽  
Pollution Level ◽  
Data Set ◽  
Air Mass

&lt;p&gt;Present research contributes to scientific knowledge concerning spatial and temporal variation of major air pollutants with high resolution at the country scale bringing statistical information on concentrations of NOx, O&lt;sub&gt;3&lt;/sub&gt;, CO, SO&lt;sub&gt;2&lt;/sub&gt; and particulate matter with an aerodynamic diameter below 10&amp;#160;&amp;#956;m (PM&lt;sub&gt;10&lt;/sub&gt;) and below 2.5&amp;#160;&amp;#956;m (PM&lt;sub&gt;2.5&lt;/sub&gt;) during the pandemic year 2020 using an observational data set from the Romanian National Air Quality Network in seven selected cities spread out over the country. These cities have different level of development, play regional roles, might have potential influence at European scale and they are expected to be impacted by different pollution sources. Among them, three cities (Bucharest, Bra&amp;#537;ov, Ia&amp;#537;i) appear frequently on the list of the European Commission with reference to the infringement procedure that the European Commission launched against Romania in the period 2007-2020 regarding air quality.&lt;/p&gt;&lt;p&gt;Air pollutant data was complemented with local meteorological parameters at each site (atmospheric pressure, relative humidity, temperature, global solar radiation, wind speed and direction). Statistics of air pollutants provide us with an overview of air pollution in main Romanian cities.&amp;#160; Correlations between meteorological parameters and ambient pollutant levels were analyzed. Lowest air pollution levels were measured during the lockdown period in spring, as main traffic and non-essential activities were severely restricted. Among exceptions were the construction activities that were not interrupted. During 2020, some of selected cities experienced few pollution episodes which were due to dust transport from Sahara desert. However, in Bucharest metropolitan area, some cases with high pollution level were found correlated with local anthropogenic activity namely, waste incinerations. Air mass origins were investigated for 72 hours back by computing the air mass backward trajectories using the HYSPLIT model. Dust load and spatial distribution of the aerosol optical depth with BSC-DREAM8b v2.0 and NMBM/BSC-Dust models showed the area with dust particles transport during the dust events.&lt;/p&gt;&lt;p&gt;The obtained results are important for investigations of sources of air pollution and for modeling of air quality.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&amp;#160;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgment:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The research leading to these results has received funding from the NO Grants 2014-2021, under Project contract no. 31/2020, EEA-RO-NO-2019-0423 project. NOAA Air Resources Laboratory for HYSPLIT transport model, available at READY website https://www.ready.noaa.gov &amp;#160;and the Barcelona dust forecast center for BSC-DREAM8b and NMBM/BSC-Dust models, available at: &amp;#160;https://ess.bsc.es/bsc-dust-daily-forecast are also acknowledged. The data regarding ground-based air pollution and meteorology by site was extracted from the public available Romanian National Air Quality Database, www.calitateaer.ro.&lt;/p&gt;

scholarly journals Effects of meteorology and emissions on urban air quality: a quantitative statistical approach to long-term records (1999–2016) in Seoul, South Korea

2018 ◽  
Vol 18 (21) ◽  
pp. 16121-16137 ◽  
Author(s):  
Jihoon Seo ◽  
Doo-Sun R. Park ◽  
Jin Young Kim ◽  
Daeok Youn ◽  
Yong Bin Lim ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
South Korea ◽  
Meteorological Conditions ◽  
Meteorological Variables ◽  
Urban Air ◽  
Short Term ◽  
Long Term Trends ◽  
Local Emissions

Abstract. Together with emissions of air pollutants and precursors, meteorological conditions play important roles in local air quality through accumulation or ventilation, regional transport, and atmospheric chemistry. In this study, we extensively investigated multi-timescale meteorological effects on the urban air pollution using the long-term measurements data of PM10, SO2, NO2, CO, and O3 and meteorological variables over the period of 1999–2016 in Seoul, South Korea. The long-term air quality data were decomposed into trend-free short-term components and long-term trends by the Kolmogorov–Zurbenko filter, and the effects of meteorology and emissions were quantitatively isolated using a multiple linear regression with meteorological variables. In terms of short-term variability, intercorrelations among the pollutants and meteorological variables and composite analysis of synoptic meteorological fields exhibited that the warm and stagnant conditions in the migratory high-pressure system are related to the high PM10 and primary pollutant, while the strong irradiance and low NO2 by high winds at the rear of a cyclone are related to the high O3. In terms of long-term trends, decrease in PM10 (−1.75 µg m−3 yr−1) and increase in O3 (+0.88 ppb yr−1) in Seoul were largely contributed by the meteorology-related trends (−0.94 µg m−3 yr−1 for PM10 and +0.47 ppb yr−1 for O3), which were attributable to the subregional-scale wind speed increase. Comparisons with estimated local emissions and socioeconomic indices like gross domestic product (GDP) growth and fuel consumptions indicate probable influences of the 2008 global economic recession as well as the enforced regulations from the mid-2000s on the emission-related trends of PM10 and other primary pollutants. Change rates of local emissions and the transport term of long-term components calculated by the tracer continuity equation revealed a decrease in contributions of local emissions to the primary pollutants including PM10 and an increase in contributions of local secondary productions to O3. The present results not only reveal an important role of synoptic meteorological conditions on the episodic air pollution events but also give insights into the practical effects of environmental policies and regulations on the long-term air pollution trends. As a complementary approach to the chemical transport modeling, this study will provide a scientific background for developing and improving effective air quality management strategy in Seoul and its metropolitan area.

Atmospheric satellite-based and in situ surface observations on summertime trace gases (CO, CO2, CH4) over the metropolitan area of Bucharest

2020 ◽  
Author(s):  
Marius-Paul Corbu ◽  
Andreea Calcan ◽  
Ioana Vizireanu ◽  
Denisa Elena Moaca ◽  
Robert-Valentin Chiritescu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Metropolitan Area ◽  
Financial Support ◽  
Trace Gases ◽  
Air Pollutant ◽  
Data Set ◽  
Air Mass ◽  
Synoptic Conditions

&lt;p&gt;Although anthropogenic emissions of trace gases have decreased over the last decades in Europe, strong additional reductions are required to reach the goals of the Paris climate agreements. In addition, air pollution is an issue of great concern for the inhabitants of the metropolitan area of Bucharest, as the local air quality is often poor. The rapid development of the city, increased traffic volume from a mixed vehicle fleet (different technologies and fuels), and other factors are strong contributors of emissions of greenhouse gases and air pollutants in Bucharest.&lt;/p&gt;&lt;p&gt;The goal of this research was the assessment of CO, CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; concentrations in Bucharest, identification of potential emissions hotspots and their causes (anthropogenic or natural/biogenic, local or distant) and determination of the background values.&lt;/p&gt;&lt;p&gt;Measurements were performed in summer 2019 in four districts of Bucharest covering about two thirds of the metropolitan area during the Romanian Methane Emissions from Oil&amp;gas (ROMEO) campaign with high resolution (1 sec). These data sets were complemented with satellite observations of CO and CH&lt;sub&gt;4&lt;/sub&gt; from Copernicus Sentinel-5P at a resolution of 7 km&lt;sup&gt;2&lt;/sup&gt;.&lt;/p&gt;&lt;p&gt;Hourly meteorological data, temperature, relative humidity, wind speed and direction, and atmospheric pressure were added to the air pollutant data set because synoptic conditions can strongly influence the levels of pollution. Air mass origins were investigated by computing backward air mass trajectories using the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model for 72 hours back.&lt;/p&gt;&lt;p&gt;Points of high concentrations of CO, CO&lt;sub&gt;2&lt;/sub&gt;, CH&lt;sub&gt;4&lt;/sub&gt; near the surface were identified which are, most likely, linked to local anthropogenic activities in the nearby surroundings. We identified a variation of concentrations of CO from 0.01 to 101 ppm, of CO&lt;sub&gt;2&lt;/sub&gt; from 388 to 6556 ppm, and of CH&lt;sub&gt;4&lt;/sub&gt; from 1.89 to 246 ppm, while background levels are as follows: 0.071&amp;#177;0.042 ppm CO, 392.68&amp;#177;3.01 ppm CO&lt;sub&gt;2&lt;/sub&gt;, and 1.93&amp;#177;0.016 ppm CH&lt;sub&gt;4&lt;/sub&gt;.&lt;/p&gt;&lt;p&gt;Results of our study provide an up to date quantitative image of CO, CO&lt;sub&gt;2&lt;/sub&gt;, CH&lt;sub&gt;4&lt;/sub&gt; hotspots in the Bucharest area, which is important for modeling air quality and may also help to improve the relationships between column integrated air pollution data with in situ ground observations.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgement:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;This research is supported by ROMEO project, developed under UNEP&amp;#8217;s financial support PCA/CCAC/UU/DTIE19-EN652. Partial financial support from UB198/Int project is also acknowledged.&lt;/p&gt;&lt;p&gt;The authors acknowledge the free use of tropospheric CO and CH&lt;sub&gt;4&lt;/sub&gt; column data from TROPOMI (Sentinel-5P) sensor from https://s5phub.copernicus.eu and the NOAA Air Resources Laboratory for the provision of the HYSPLIT transport model available at READY website https://www.ready.noaa.gov&lt;/p&gt;&lt;p&gt;Special thanks to all INCAS technical staff for their support in performing the campaigns.&lt;/p&gt;

scholarly journals Investigations of temporal and spatial distribution of precursors SO<sub>2</sub> and NO<sub>2</sub> vertical columns in the North China Plain using mobile DOAS

2018 ◽  
Vol 18 (3) ◽  
pp. 1535-1554 ◽  
Author(s):  
Fengcheng Wu ◽  
Pinhua Xie ◽  
Ang Li ◽  
Fusheng Mou ◽  
Hao Chen ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Air Quality ◽  
North China Plain ◽  
North China ◽  
Emission Sources ◽  
Temporal And Spatial Distribution ◽  
Air Mass ◽  
The North ◽  
The North China Plain ◽  
Temporal And Spatial

Abstract. Recently, Chinese cities have suffered severe events of haze air pollution, particularly in the North China Plain (NCP). Investigating the temporal and spatial distribution of pollutants, emissions, and pollution transport is necessary to better understand the effect of various sources on air quality. We report on mobile differential optical absorption spectroscopy (mobile DOAS) observations of precursors SO2 and NO2 vertical columns in the NCP in the summer of 2013 (from 11 June to 7 July) in this study. The different temporal and spatial distributions of SO2 and NO2 vertical column density (VCD) over this area are characterized under various wind fields. The results show that transport from the southern NCP strongly affects air quality in Beijing, and the transport route, particularly SO2 transport on the route of Shijiazhuang–Baoding–Beijing, is identified. In addition, the major contributors to SO2 along the route of Shijiazhuang–Baoding–Beijing are elevated sources compared to low area sources for the route of Dezhou–Cangzhou–Tianjin–Beijing; this is found using the interrelated analysis between in situ and mobile DOAS observations during the measurement periods. Furthermore, the discussions on hot spots near the city of JiNan show that average observed width of polluted air mass is 11.83 and 17.23 km associated with air mass diffusion, which is approximately 60 km away from emission sources based on geometrical estimation. Finally, a reasonable agreement exists between the Ozone Monitoring Instrument (OMI) and mobile DOAS observations, with a correlation coefficient (R2) of 0.65 for NO2 VCDs. Both datasets also have a similar spatial pattern. The fitted slope of 0.55 is significantly less than unity, which can reflect the contamination of local sources, and OMI observations are needed to improve the sensitivities to the near-surface emission sources through improvements of the retrieval algorithm or the resolution of satellites.

scholarly journals Air quality and acid deposition impacts of local emissions and transboundary air pollution in Japan and South Korea

2019 ◽  
Vol 19 (20) ◽  
pp. 13309-13323 ◽  
Author(s):  
Steve Hung Lam Yim ◽  
Yefu Gu ◽  
Matthew A. Shapiro ◽  
Brent Stephens
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
South Korea ◽  
East Asia ◽  
Human Health ◽  
Acid Deposition ◽  
Seasonal Variations ◽  
Ambient Air ◽  
Transboundary Air Pollution ◽  
Local Emissions

Abstract. Numerous studies have reported that ambient air pollution, which has both local and long-range sources, causes adverse impacts on the environment and human health. Previous studies have investigated the impacts of transboundary air pollution (TAP) in East Asia, albeit primarily through analyses of episodic events. In addition, it is useful to better understand the spatiotemporal variations in TAP and the resultant impact on the environment and human health. This study aimed at assessing and quantifying the air quality impacts in Japan and South Korea due to local emissions and TAP from sources in East Asia - one of the most polluted regions in the world. We applied state-of-the-science atmospheric models to simulate air quality in East Asia and then analyzed the air quality and acid deposition impacts of both local emissions and TAP sources in Japan and South Korea. Our results show that ∼ 30 % of the annual average ambient PM2.5 concentrations in Japan and South Korea in 2010 were contributed to by local emissions within each country, while the remaining ∼ 70 % were contributed to by TAP from other countries in the region. More detailed analyses also revealed that the local contribution was higher in the metropolises of Japan (∼ 40 %–79 %) and South Korea (∼ 31 %–55 %) and that minimal seasonal variations in surface PM2.5 occurred in Japan, whereas there was a relatively large variation in South Korea in the winter. Further, among all five studied anthropogenic emission sectors of China, the industrial sector represented the greatest contributor to annual surface PM2.5 concentrations in Japan and South Korea, followed by the residential and power generation sectors. Results also show that TAP's impact on acid deposition (SO42- and NO3-) was larger than TAP's impact on PM2.5 concentrations (accounting for over 80 % of the total deposition), and that seasonal variations in acid deposition were similar for both Japan and South Korea (i.e., higher in both the winter and summer). Finally, wet deposition had a greater impact on mixed forests in Japan and savannas in South Korea. Given these significant impacts of TAP in the region, it is paramount that cross-national efforts should be taken to mitigate air pollution problems across East Asia.

scholarly journals Understanding the Spatial-Temporal Patterns and Influential Factors on Air Quality Index: The Case of North China

2019 ◽  
Vol 16 (16) ◽  
pp. 2820 ◽  
Author(s):  
Wenxuan Xu ◽  
Yongzhong Tian ◽  
Yongxue Liu ◽  
Bingxue Zhao ◽  
Yongchao Liu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Wind Speed ◽  
Quality Index ◽  
North China ◽  
Ambient Air ◽  
Air Quality Index ◽  
Rapid Expansion ◽  
Spatial Data Analysis ◽  
Prevailing Wind Direction

North China has become one of the worst air quality regions in China and the world. Based on the daily air quality index (AQI) monitoring data in 96 cities from 2014–2016, the spatiotemporal patterns of AQI in North China were investigated, then the influence of meteorological and socio-economic factors on AQI was discussed by statistical analysis and ESDA-GWR (exploratory spatial data analysis-geographically weighted regression) model. The principal results are as follows: (1) The average annual AQI from 2014–2016 exceeded or were close to the Grade II standard of Chinese Ambient Air Quality (CAAQ), although the area experiencing heavy pollution decreased. Meanwhile, the positive spatial autocorrelation of AQI was enhanced in the sample period. (2) The occurrence of a distinct seasonal cycle in air pollution which exhibit a sinusoidal pattern of fluctuations and can be described as “heavy winter and light summer.” Although the AQI generally decreased in other seasons, the air pollution intensity increased in winter with the rapid expansion of higher AQI value in the southern of Hebei and Shanxi. (3) The correlation analysis of daily meteorological factors and AQI shows that air quality can be significantly improved when daily precipitation exceeds 10 mm. In addition, except for O3, wind speed has a negative correlation with AQI and major pollutants, which was most significant in winter. Meanwhile, pollutants are transmitted dynamically under the influence of the prevailing wind direction, which can result in the relocation of AQI. (4) According to ESDA-GWR analysis, on an annual scale, car ownership and industrial production are positively correlated with air pollution; whereas increase of wind speed, per capita gross domestic product (GDP), and forest coverage are conducive to reducing pollution. Local coefficients show spatial differences in the effects of different factors on the AQI. Empirical results of this study are helpful for the government departments to formulate regionally differentiated governance policies regarding air pollution.

scholarly journals The Impact of Mount Washington on the Height of the Boundary Layer and the Vertical Structure of Temperature and Moisture

Atmosphere ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 293 ◽  
Author(s):  
Eric Kelsey ◽  
Adriana Bailey ◽  
Georgia Murray
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Complex Terrain ◽  
Free Atmosphere ◽  
Air Mass ◽  
Meteorological Observations ◽  
Measurement Strategies ◽  
The Impact ◽  
Mass Type ◽  
Mount Washington

Discrimination of the type of air mass along mountain slopes can be a challenge and is not commonly performed, but is critical for identifying factors responsible for influencing montane weather, climate, and air quality. A field campaign to measure air mass type and transitions on the summit of Mount Washington, New Hampshire, USA was performed on 19 August 2016. Meteorological observations were taken at the summit and at several sites along the east and west slopes. Ozone concentrations were measured at the summit and on the valley floor. Additionally, water vapor stable isotopes were measured from a truck that drove up and down the Mount Washington Auto Road concurrent with radiosonde launches that profiled the free atmosphere. This multivariate perspective revealed thermal, moisture, and air mass height differences among the free atmosphere, leeward, and windward mountain slopes. Both thermally and mechanically forced upslope flows helped shape these differences by altering the height of the boundary layer with respect to the mountain surface. Recommendations for measurement strategies hoping to develop accurate observational climatologies of air mass exposure in complex terrain are discussed and will be important for evaluating elevation-dependent warming and improving forecasting for weather and air quality.

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