Identification of aerosol types over an urban site based on air-mass trajectory classification

2015 ◽  
Vol 164-165 ◽  
pp. 142-155 ◽  
Author(s):  
G.V. Pawar ◽  
P.C.S. Devara ◽  
G.R. Aher
Keyword(s):  
Urban Site ◽  
Air Mass ◽  
Trajectory Classification ◽  
Aerosol Types ◽  
Air Mass Trajectory

scholarly journals Identification of the Aerosol Types over Athens, Greece: The Influence of Air-Mass Transport

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
D. G. Kaskaoutis ◽  
P. G. Kosmopoulos ◽  
H. D. Kambezidis ◽  
P. T. Nastos
Keyword(s):  
Winter Season ◽  
Saharan Dust ◽  
Dust Particles ◽  
Hysplit Model ◽  
Air Mass ◽  
Back Trajectories ◽  
Air Masses ◽  
Local Pollution ◽  
Coarse Mode ◽  
Aerosol Types

Aerosol optical depth at 550 nm () and fine-mode (FM) fraction data from Terra-MODIS were obtained over the Greater Athens Area covering the period February 2000–December 2005. Based on both and FM values three main aerosol types have been discriminated corresponding to urban/industrial aerosols, clean maritime conditions, and coarse-mode, probably desert dust, particles. Five main sectors were identified for the classification of the air-mass trajectories, which were further used in the analysis of the ( and FM data for the three aerosol types). The HYSPLIT model was used to compute back trajectories at three altitudes to investigate the relation between -FM and wind sector depending on the altitude. The accumulation of local pollution is favored in spring and corresponds to air masses at lower altitudes originating from Eastern Europe and the Balkan. Clean maritime conditions are rare over Athens, limited in the winter season and associated with air masses from the Western or Northwestern sector. The coarse-mode particles origin seems to be more complicated proportionally to the season. Thus, in summer the Northern sector dominates, while in the other seasons, and especially in spring, the air masses belong to the Southern sector enriched with Saharan dust aerosols.

scholarly journals Tracing the evolution of morphology and mixing state of soot particles along with the movement of an Asian dust storm

2020 ◽  
Author(s):  
Liang Xu ◽  
Satoshi Fukushima ◽  
Sophie Sobanska ◽  
Kotaro Murata ◽  
Ayumi Naganuma ◽  
...  
Keyword(s):  
Regional Climate ◽  
Microscopic Analysis ◽  
Asian Dust ◽  
Urban Site ◽  
Dust Event ◽  
The East China Sea ◽  
Soot Particles ◽  
New Findings ◽  
Optical Calculation ◽  
Aerosol Types

Abstract. Tracing the aging progress of soot particles during transport is highly challenging. An Asian dust event could provide an ideal opportunity to trace the continuous aging progress of long-range transported soot particles. Here, we collected individual aerosol particles at an inland urban site (T1) and a coastal urban site (T2) in China and a coastal site (T3) in southwestern Japan during an Asian dust event. Microscopic analysis showed that the number fraction of soot-bearing particles increased from 19 % to 22 % from T1 to T2 in China but surprisingly increased to 56 % at T3 in Japan. The dominant fresh soot (71 %) at T1 became partially embedded (70 %) at T2 and fully embedded (84 %) at T3. These results indicated that the soot particles had lower deposition than other aerosol types and became more aged from T1 to T3. The fractal dimension of the soot particles slightly changed from 1.74 at T1 and 1.78 at T2 but significantly became 1.91 at T3. We found that the soot morphology compressed depending on secondary coating thickness and relative humidity. Moreover, we observed a unique mixing structure at T3 that tiny soot particles were seemly broken from large ones cross the East China Sea and distributed in organic coatings instead of sulfate core in particles. Our study provide important constraints of the morphological effects to better understand changes of microscopic structures of soot. These new findings will be helpful to improve optical calculation and modeling of soot particles and their regional climate effects in the atmosphere.

An air-mass trajectory study of the transport of radioactivity from Fukushima to Thessaloniki, Greece and Milan, Italy

2013 ◽  
Vol 75 ◽  
pp. 163-170 ◽  
Author(s):  
A. Ioannidou ◽  
E. Giannakaki ◽  
M. Manolopoulou ◽  
S. Stoulos ◽  
E. Vagena ◽  
...  
Keyword(s):  
Air Mass ◽  
Air Mass Trajectory

scholarly journals Relationships between submicrometer particulate air pollution and air mass history in Beijing, China, 2004–2006

2008 ◽  
Vol 8 (20) ◽  
pp. 6155-6168 ◽  
Author(s):  
B. Wehner ◽  
W. Birmili ◽  
F. Ditas ◽  
Z. Wu ◽  
M. Hu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Large Scale ◽  
Northwest China ◽  
Back Trajectory ◽  
Anthropogenic Aerosol ◽  
Air Mass ◽  
Air Masses ◽  
Rapid Economic Growth ◽  
Trajectory Classification ◽  
History Of

Abstract. The Chinese capital Beijing is one of the global megacities where the effects of rapid economic growth have led to complex air pollution problems that are not well understood. In this study, ambient particle number size distributions in Beijing between 2004 and 2006 are analysed as a function of regional meteorological transport. An essential result is that the particle size distribution in Beijing depends to large extent on the history of the synoptic scale air masses. A first approach based on manual back trajectory classification yielded differences in particulate matter mass concentration by a factor of two between four different air mass categories, including three main wind directions plus the case of stagnant air masses. A back trajectory cluster analysis refined these results, yielding a total of six trajectory clusters. Besides the large scale wind direction, the transportation speed of an air mass was found to play an essential role on the PM concentrations in Beijing. Slow-moving air masses were shown to be associated with an effective accumulation of surface-based anthropogenic emissions due to both, an increased residence time over densely populated land, and their higher degree of vertical stability. For the six back trajectory clusters, differences in PM1 mass concentrations by a factor of 3.5, in the mean air mass speed by a factor of 6, and in atmospheric visibility by a factor of 4 were found. The main conclusion is that the air quality in Beijing is not only degraded by anthropogenic aerosol sources from within the megacity, but also by sources across the entire Northwest China plain depending on the meteorological situation.

scholarly journals Measurement report: New particle formation characteristics at an urban and a mountain station in northern China

2021 ◽  
Vol 21 (23) ◽  
pp. 17885-17906
Author(s):  
Ying Zhou ◽  
Simo Hakala ◽  
Chao Yan ◽  
Yang Gao ◽  
Xiaohong Yao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Formation Rate ◽  
Northern China ◽  
Particle Formation ◽  
Urban Site ◽  
New Particle Formation ◽  
Large Area ◽  
Air Mass ◽  
Mountain Site ◽  
Favorable Conditions

Abstract. Atmospheric new particle formation (NPF) events have attracted increasing attention for their contribution to the global aerosol number budget and therefore their effects on climate, air quality and human health. NPF events are regarded as a regional phenomenon, occurring over a large area. Most observations of NPF events in Beijing and its vicinity were conducted in populated areas, whereas observations of NPF events on mountaintops with low anthropogenic emissions are still rare in China. The spatial variation of NPF event intensity has not been investigated in detail by incorporating both urban areas and mountain measurements in Beijing. Here, we provide NPF event characteristics in summer 2018 and 2019 at urban Beijing and a comparison of NPF event characteristics – NPF event frequency, formation rate and growth rate – by comparing an urban Beijing site and a background mountain site separated by ∼80 km from 14 June to 14 July 2019, as well as giving insights into the connection between both locations. During parallel measurements at urban Beijing and mountain background areas, although the median condensation sink during the first 2 h of the common NPF events was around 0.01 s−1 at both sites, there were notable differences in formation rates between the two locations (median of 5.42 cm−3 s−1 at the urban site and 1.13 cm−3 s−1 at the mountain site during the first 2 h of common NPF events). In addition, the growth rates in the 7–15 nm range for common NPF events at the urban site (median of 7.6 nm h−1) were slightly higher than those at the mountain site (median of 6.5 nm h−1). To understand whether the observed events were connected, we compared air mass trajectories as well as meteorological conditions at both stations. Favorable conditions for the occurrence of regional NPF events were largely affected by air mass transport. Overall, our results demonstrate a clear inhomogeneity of regional NPF within a distance of ∼100 km, possibly due to the discretely distributed emission sources.

Advective Transport Modeling for Spatial Analysis of Atmospheric Aerosols over Lagos Area of South Western Nigeria

2019 ◽  
Vol 44 ◽  
pp. 91-98
Author(s):  
Mayowa Adeoye Lala ◽  
Olusola Adedayo Adesina ◽  
Anselm Igbafe
Keyword(s):  
Atlantic Ocean ◽  
Atmospheric Aerosols ◽  
Ground Level ◽  
Advective Transport ◽  
Average Wind Speed ◽  
Study Region ◽  
Air Mass ◽  
Westerly Direction ◽  
Resource Laboratory ◽  
Air Mass Trajectory

In this study atmospheric aerosols distribution over Lagos area of southwestern part of Nigeria was analyzed using backward air mass trajectory model. GPS information of the study region was used to simulate meteorological variables and aerosol data that have been stored by satellite imagery from the National Oceanography and Atmospheric Administration (NOAA) and Air Resource Laboratory (ARL). Hybrid Single-Particle Lagrangian Integrated Trajectories HYSPLIT was used to determine the wind-field information and also to obtain the backward air mass trajectory for atmospheric aerosols transport pattern at heights 0, 1000m and 2000m above ground level. The result showed that aerosols of sea-salt origin evolved from Atlantic ocean and spread over Lagos during the period under consideration. The average wind speed observed within the period ranged between 4 and 7m/s in south westerly direction which is attributed to the influence Atlantic Ocean. The results also showed that aerosol traversing Lagos area are mainly sea salts

scholarly journals O3 Sensitivity and Contributions of Different NMHC Sources in O3 Formation at Urban and Suburban Sites in Shanghai

Atmosphere ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 295
Author(s):  
Haotian Lin ◽  
Ming Wang ◽  
Yusen Duan ◽  
Qingyan Fu ◽  
Wenhao Ji ◽  
...  
Keyword(s):  
Pollution Control ◽  
Anthropogenic Sources ◽  
Urban Site ◽  
Air Pollution Control ◽  
Vehicular Emission ◽  
Air Mass ◽  
Solvent Use ◽  
The Yrd ◽  
Different Sources ◽  
Suburban Site

Ground-level ozone (O3) pollution is still one of the priorities and challenges for air pollution control in the Yangtze River Delta (YRD) region of China. Understanding the relationship of O3 with its precursors and contributions of different sources in O3 formation is essential for the development of an O3 control strategy. This study analyzed O3 sensitivity to its precursors using a box model based on online observations of O3, non-methane hydrocarbons (NMHCs), nitrogen oxides (NOx), and carbon monoxide (CO) at an urban site and a suburban site in Shanghai in July 2017. Anthropogenic sources of NMHCs were identified using the positive matrix factorization (PMF) receptor model, and then contributions of different sources in O3 formation were estimated by the observation-based model (OBM). The relative incremental reactivity (RIR) values calculated by the OBM suggest that O3 formation at the urban site was in the NMHC-limited regime, while O3 formation at the suburban site tended between the transition regime and the NMHC-limited regime. Vehicular emission and liquefied petrochemical gas (LPG) use or aged air mass were found to be the two largest contributors at the urban and suburban sites in July, followed by paint and solvent use, and the petrochemical industry. However, from the perspective of O3 formation, vehicular emission and paint and solvent use were the largest two contributors at two sites due to the higher RIR values for paint and solvent use. In addition, the influence of transport on O3 sensitivity was identified by comparing O3 sensitivity at the suburban site across two days with different air mass paths. The result revealed that O3 formation in Shanghai is not only related to local emissions but also influenced by emissions from neighboring provinces. These findings on O3–NMHC–NOX sensitivity, contributions of different sources in O3 formation, and influence of transport could be useful for O3 pollution control in the YRD region. Nevertheless, more quantitative analyses on transport and further evaluation of the uncertainty of the OBM are still needed in future.

scholarly journals Temperature and vapour-trajectory controls on the stable-isotope signal in Canadian Rocky Mountain snowpacks

2009 ◽  
Vol 55 (191) ◽  
pp. 485-498 ◽  
Author(s):  
K.E. Sinclair ◽  
S.J. Marshall
Keyword(s):  
Rocky Mountain ◽  
Water Isotopes ◽  
Canadian Rocky Mountains ◽  
Deuterium Excess ◽  
Stable Water Isotopes ◽  
Air Mass ◽  
Trajectory Classification ◽  
The Mean ◽  
Effects Of Temperature ◽  
Using Data

AbstractThe effects of temperature and seasonal air-mass trajectories on stable water isotopes in alpine snowpacks are investigated using meteorological and snow-pit data at two alpine field sites in the Canadian Rocky Mountains: Haig Glacier, Alberta, and Opabin Glacier, British Columbia. Snow pits were sampled through three accumulation seasons (October–June, 2004/05, 2005/06 and 2006/07) for δ18O, δD, temperature and density. The isotopic characteristics of precipitation over these time periods, including the local meteoric waterline and average δ18O, δD and deuterium excess, were defined using this dataset. Individual snowfall events over the three seasons were identified in the accumulation records from both sites and then fit to snow-pit stratigraphies to determine their mean isotopic characteristics. A trajectory classification was produced for all events, and the key meteorological characteristics of each trajectory class were investigated using data from alpine field sites and a suite of meteorological records from the region. An analysis of the relative influences of temperature and air-mass trajectory on snow isotope ratios reveals some separation in mean δ18O between storm classes. However, the separation appears to be driven primarily by the mean temperature of each class rather then being a direct effect of vapour pathway.

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