Distant source contributions to PM10 profile evaluated by SOM based cluster analysis of air mass trajectory sets

2010 ◽  
Vol 44 (7) ◽  
pp. 892-899 ◽  
Author(s):  
Ferhat Karaca ◽  
Fatih Camci
Keyword(s):  
Cluster Analysis ◽  
Distant Source ◽  
Air Mass ◽  
Source Contributions ◽  
Air Mass Trajectory

scholarly journals Variations in Levels and Sources of Atmospheric VOCs during the Continuous Haze and Non-Haze Episodes in the Urban Area of Beijing: A Case Study in Spring of 2019

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 171
Author(s):  
Lihui Zhang ◽  
Xuezhong Wang ◽  
Hong Li ◽  
Nianliang Cheng ◽  
Yujie Zhang ◽  
...  
Keyword(s):  
Diesel Exhaust ◽  
Urban Areas ◽  
Photochemical Reaction ◽  
Petrochemical Industry ◽  
Exhaust Emission ◽  
Long Distance ◽  
Air Mass ◽  
Source Contributions ◽  
The Government ◽  
Haze Days

To better evaluate the variations in concentration characteristics and source contributions of atmospheric volatile organic compounds (VOCs) during continuous haze days and non-haze days, hourly observations of atmospheric VOCs were conducted using a continuous on-line GC-FID (Airmo VOC GC-866) monitoring system during 1–15 March 2019, in urban areas of Beijing, China. The results showed that the total VOC concentrations during haze days and non-haze days were 59.13 ± 31.08 μg/m3 and 16.91 ± 7.19 μg/m3, respectively. However, the average O3 concentrations during the two haze days were lower than those of non-haze days due to the extremely low concentrations at night instead of the reported lower photochemical reaction in daytime. The ratio of OH radical concentration during haze and non-haze days indicating that the rate of photochemical reaction during haze days was higher than those of non-haze days from 13:00–19:00. The stable air conditions and the local diesel emission at night were the main reasons for the decreased O3 concentrations during haze days. Six major sources were identified by positive matrix factorization (PMF), namely, diesel exhaust, combustion, gasoline evaporation, solvent usage, gasoline exhaust, and the petrochemical industry, contributing 9.93%, 25.29%, 3.90%, 16.88%, 35.59% and 8.41%, respectively, during the whole observation period. The contributions of diesel exhaust and the petrochemical industry emissions decreased from 26.14% and 6.43% during non-haze days to 13.70% and 2.57%, respectively, during haze days. These reductions were mainly ascribed to the emergency measures that the government implemented during haze days. In contrast, the contributions of gasoline exhaust increased from 34.92% during non-haze days to 48.77% during haze days. The ratio of specific VOC species and PMF both showed that the contributions of gasoline exhaust emission increased during haze days. The backward trajectories, potential source contribution function (PSCF) and concentration weighted trajectory (CWT) showed that the air mass of VOCs during haze days was mainly affected by the short-distance transportation from the southwestern of Hebei province. However, the air mass of VOCs during non-haze days was mainly affected by the long-distance transportation from the northwest.

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

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

Source region cluster analysis in the high-altitude measuring site of Chacaltaya with WRF and FLEXPART

2020 ◽  
Author(s):  
Diego Aliaga ◽  
Victoria Sinclair ◽  
Zha Qiaozhi ◽  
Marcos Andrade ◽  
Claudia Mohr ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
High Altitude ◽  
Long Range ◽  
Measurement Data ◽  
Particle Dispersion ◽  
Particle Nucleation ◽  
Free Troposphere ◽  
Data Set ◽  
Air Mass ◽  
Air Masses

<p>Measuring aerosol at high altitude sites is useful as it enables sampling of the free troposphere over long time frames. However, in order to draw conclusions from station measurement data, we need to determine which air mass sources are present at any given sampling time. This task is challenging at mountain sites, due to complex topography which in turn drives complex meteorology. Between December 2017 and May 2018, the Southern hemisphere high ALTitude Experiment on particle Nucleation And growth (SALTENA) campaign was conducted at Chacaltaya in Bolivia at 5240 m a.s.l. The data set obtained in this campaign contains records of nearly all relevant aerosol characteristics and aerosol precursors. To identify the source regions of the observed air masses we performed high resolution (down to 1 km) simulations with the Weather Research and Forecasting Model (WRF). The WRF model output is then used to as input to the Lagrangian particle dispersion model (FLEXPART). FLEXPART simulations are initialised every hour and 20 thousand particles are released per hour and track backwards in time for 96 hours. The FLEXPART footprint output is regridded onto a log-polar cylindrical grid where we perform a ‘K-means’ cluster analysis on the 3D cells defined by the grid. The cells are clustered based on the time series of their source receptor relationship (i.e. emission sensitivities), producing regions (clusters) resolved not only in the horizontal but also the vertical domain. Our results show that regions located close to the station (<100km) have a low but persistent influence with diurnal variations and close contact to the surface. Mid-range regions (100-800km) have the highest influence with a higher percentage of air masses from the free troposphere. Long-range regions (>800km) have a higher influence than the short-range regions but lower than the middle-range regions. Most of the air masses from these long-range regions come from the free troposphere. With this method we have successfully resolved the various air mass influences at the measurement site. The high meteorological resolution and the stochastic nature of FLEXPART are seminal for capturing the transport pathways.</p>

Local and distant source contributions to secondary organic aerosol in the Beijing urban area in summer

2016 ◽  
Vol 124 ◽  
pp. 176-185 ◽  
Author(s):  
Jian Lin ◽  
Junling An ◽  
Yu Qu ◽  
Yong Chen ◽  
Ying Li ◽  
...  
Keyword(s):  
Urban Area ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Distant Source ◽  
Source Contributions

scholarly journals The Relationship between Air-Mass Trajectories and the Abundance of Dust-Borne Prokaryotes at the SE Mediterranean Sea

Atmosphere ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 280 ◽  
Author(s):  
Eyal Rahav ◽  
Natalia Belkin ◽  
Adina Paytan ◽  
Barak Herut
Keyword(s):  
Mediterranean Sea ◽  
Temporal Variability ◽  
Airborne Microorganisms ◽  
Coastal Site ◽  
Air Mass ◽  
Dust Aerosols ◽  
Air Mass Trajectories ◽  
Airborne Microbes ◽  
The Relationship ◽  
Air Mass Trajectory

Airborne prokaryotes are transported along with dust/aerosols, yet very little attention is given to their temporal variability above the oceans and the factors that govern their abundance. We analyzed the abundance of autotrophic (cyanobacteria) and heterotopic airborne microbes in 34 sampling events between 2015–2018 at a coastal site in the SE Mediterranean Sea. We show that airborne autotrophic (0.2–7.6 cells × 103 m−3) and heterotrophic (0.2–30.6 cells × 103 m−3) abundances were affected by the origin and air mass trajectory, and the concentration of dust/aerosols in the air, while seasonality was not coherent. The averaged ratio between heterotrophic and autotrophic prokaryotes in marine-dominated trajectories was ~1.7 ± 0.6, significantly lower than for terrestrial routes (6.8 ± 6.1). Airborne prokaryotic abundances were linearly and positively correlated to the concentrations of total aerosol, while negatively correlated with the aerosol’s anthropogenic fraction (using Pb/Al or Cu/Al ratios as proxies). While aerosols may play a major role in dispersing terrestrial and marine airborne microbes in the SE Mediterranean Sea, the mechanisms involved in the dispersal and diversity of airborne microorganisms remain to be studied and should include standardization in collection and analysis protocols.

scholarly journals Biogenic SOA formation through gas-phase oxidation and gas-to-particle partitioning – comparison between process models of varying complexity

2014 ◽  
Vol 14 (8) ◽  
pp. 11001-11040
Author(s):  
E. Hermansson ◽  
P. Roldin ◽  
A. Rusanen ◽  
D. Mogensen ◽  
N. Kivekäs ◽  
...  
Keyword(s):  
Gas Phase ◽  
Global Climate Models ◽  
Process Models ◽  
Oxidation Products ◽  
Basis Set ◽  
Chemical Mechanism ◽  
Air Mass ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
Air Mass Trajectory

Abstract. Biogenic volatile organic compounds (BVOCs) emitted by the vegetation play an important role for the aerosol mass loadings since the oxidation products of these compounds can take part in the formation and growth of secondary organic aerosols (SOA). The concentrations and properties of BVOCs and their oxidation products in the atmosphere are poorly characterized, which leads to high uncertainties in modeled SOA mass and properties. In this study the formation of SOA has been modeled along an air mass trajectory over the northern European boreal forest using two aerosol dynamics box models where the prediction of the condensable organics from the gas-phase oxidation of BVOC is handled with schemes of varying complexity. The use of box model simulations along an air mass trajectory allows us to, under atmospheric relevant conditions, compare different model parameterizations and their effect on SOA formation. The result of the study shows that the modeled mass concentration of SOA is highly dependent on the organic oxidation scheme used to predict the oxidation products. A near-explicit treatment of organic gas-phase oxidation (Master Chemical Mechanism version 3.2) was compared to oxidation schemes that use the volatility basis set (VBS) approach. The resulting SOA mass modeled with different VBS-schemes varies by a factor of about 7 depending on how the first generation oxidation products are parameterized and how they subsequently age (e.g. how fast the gas-phase oxidation products react with the OH-radical, how they respond to temperature changes and if they are allowed to fragment during the aging process). Since the VBS approach is frequently used in regional and global climate models due to its relatively simple treatment of the oxidation products compared to near-explicit oxidation schemes; better understanding of the abovementioned processes are needed. Compared to the most commonly used VBS-schemes, the near-explicit method produces less – but more oxidized – SOA.

scholarly journals Boundaries of air mass trajectory clustering: key points and applications

2016 ◽  
Vol 14 (3) ◽  
pp. 653-662
Author(s):  
I. A. Pérez ◽  
M. L. Sánchez ◽  
M. A. García ◽  
N. Pardo
Keyword(s):  
Trajectory Clustering ◽  
Air Mass ◽  
Key Points ◽  
Air Mass Trajectory
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