scholarly journals Source–Receptor Relationships and Cluster Analysis of CO2, CH4, and CO Concentrations in West Africa: The Case of Lamto in Côte d’Ivoire

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 903 ◽  
Author(s):  
Dro Touré Tiemoko ◽  
Fidèle Yoroba ◽  
Jean-Daniel Paris ◽  
Adama Diawara ◽  
Antoine Berchet ◽  
...  
Keyword(s):  
Emission Sources ◽  
Air Masses ◽  
Clustering Technique ◽  
North East ◽  
Range Transport ◽  
Continental Origin ◽  
And Cluster Analysis ◽  
Combustion Processes ◽  
Co Concentrations ◽  
Source Receptor Relationships

The contribution in terms of long-range transport of CO2, CH4, and CO concentrations to measurements at Lamto (5°02′ W–6°13′ N) was analyzed for the 2014–2017 period using the FLEXPART model that calculates the retro-plumes of air masses arriving at the station. The identification of the source-receptor relationships was also studied with a clustering technique applied on those retro-plumes. This clustering technique enabled us to distinguish four categories of air mass transports arriving at Lamto site described as follows: oceanic and maritime origin (≈37% of the retro-plumes), continental origin (≈21%), and two hybrid clusters (≈42%). The results show that continental emission sources contribute significantly to the increases in concentrations of CO2, CH4, and CO and explain ≈40% of their variance. These emission sources are predominantly from north and north-east directions of the measurement point, and where densely populated and economically developed areas are located. In addition, the transport of air masses from these directions lead to the accumulation of CO2, CH4, and CO. Furthermore, the ratios ΔCO/ΔCH4 and ΔCO/ΔCO2 observed in the groups associated with Harmattan flows clearly show an influence of combustion processes on the continent. Thus, the grouping based on FLEXPART footprints shows an advantage compared to the use of simple trajectories for analyzing source–receptor relationships.

scholarly journals Concentration Trajectory Route of Air pollution with an Integrated Lagrangian model (C-TRAIL model v1.0) derived from the Community Multiscale Air Quality Modeling (CMAQ model v5.2)

2020 ◽  
Author(s):  
Arman Pouyaei ◽  
Yunsoo Choi ◽  
Jia Jung ◽  
Bavand Sadeghi ◽  
Chul Han Song
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Long Range ◽  
Lagrangian Model ◽  
Long Range Transport ◽  
Air Masses ◽  
Range Transport ◽  
Potential Sources ◽  
Model C ◽  
Co Concentrations

Abstract. This paper introduces a reliable and comprehensive Lagrangian output (Concentration Trajectory Route of Air pollution with Integrated Lagrangian model, C-TRAIL version 1.0) from an Eulerian air quality model for validating the source-receptor link by following real polluted air masses. To investigate the concentrations and trajectories of air masses simultaneously, we implement the trajectory-grid (TG) Lagrangian advection scheme in the CMAQ (Community Multiscale Air Quality) Eulerian model version 5.2. The TG algorithm follows the concentrations of representative air packets of species along trajectories determined by the wind field. The generated output from C-TRAIL accurately identifies the origins of pollutants. For validation, we analyzed the results of C-TRAIL during the KORUS-AQ campaign over South Korea. Initially, we implemented C-TRAIL in a simulation of CO concentrations with an emphasis on the long- and short-range transport effect. The output from C-TRAIL reveals that local trajectories were responsible for CO concentrations over Seoul during the stagnant period (May 17–22, 2016) and during the extreme pollution period (May 25–28, 2016), highly polluted air masses from China were distinguished as sources of CO transported to the Seoul Metropolitan Area (SMA). We conclude that long-range transport played a crucial role in high CO concentrations over the receptor area during this period. Furthermore, for May 2016, we find that the potential sources of CO over that SMA were the result of either local transport or long-range transport from the Shandong Peninsula and, in some cases, from north of the SMA. By identifying the trajectories of CO concentrations, one can use the results from C-TRAIL to directly link strong potential sources of pollutants to a receptor in specific regions during various time frames.

scholarly journals Concentration Trajectory Route of Air pollution with an Integrated Lagrangian model (C-TRAIL Model v1.0) derived from the Community Multiscale Air Quality Model (CMAQ Model v5.2)

2020 ◽  
Vol 13 (8) ◽  
pp. 3489-3505 ◽  
Author(s):  
Arman Pouyaei ◽  
Yunsoo Choi ◽  
Jia Jung ◽  
Bavand Sadeghi ◽  
Chul Han Song
Keyword(s):  
Air Quality ◽  
Lagrangian Model ◽  
Long Range Transport ◽  
Air Quality Model ◽  
Quality Model ◽  
Air Masses ◽  
Range Transport ◽  
Potential Sources ◽  
Model C ◽  
Co Concentrations

Abstract. This paper introduces a novel Lagrangian model (Concentration Trajectory Route of Air pollution with an Integrated Lagrangian model, C-TRAIL version 1.0) output from a Eulerian air quality model for validating the source–receptor direct link by following polluted air masses. To investigate the concentrations and trajectories of air masses simultaneously, we implement the trajectory-grid (TG) Lagrangian advection scheme in the CMAQ (Community Multiscale Air Quality) Eulerian model version 5.2. The TG algorithm follows the concentrations of representative air “packets” of species along trajectories determined by the wind field. The diagnostic output from C-TRAIL accurately identifies the origins of pollutants. For validation, we analyze the results of C-TRAIL during the KORUS-AQ campaign over South Korea. Initially, we implement C-TRAIL in a simulation of CO concentrations with an emphasis on the long- and short-range transport effects. The output from C-TRAIL reveals that local trajectories were responsible for CO concentrations over Seoul during the stagnant period (17–22 May 2016) and during the extreme pollution period (25–28 May 2016), highly polluted air masses from China were distinguished as sources of CO transported to the Seoul Metropolitan Area (SMA). We conclude that during the study period, long-range transport played a crucial role in high CO concentrations over the receptor area. Furthermore, for May 2016, we find that the potential sources of CO over the SMA were the result of either local transport or long-range transport from the Shandong Peninsula and, in some cases, from regions north of the SMA. By identifying the trajectories of CO concentrations, one can use the results from C-TRAIL to directly link strong potential sources of pollutants to a receptor in specific regions during various time frames.

New Climatic Zones in Iran: A Comparative Study of Different Empirical Methods and Clustering Technique

2021 ◽  
Author(s):  
Faezeh Abbasi ◽  
Saeed Bazgeer ◽  
Parviz Rezazadeh Kalehbasti ◽  
Ebrahim Asadi Oskoue ◽  
Masoud Haghighat ◽  
...  
Keyword(s):  
Zagros Mountains ◽  
Empirical Methods ◽  
Climate Classification ◽  
Climate Type ◽  
Air Masses ◽  
Clustering Technique ◽  
Mountainous Regions ◽  
Synoptic Weather ◽  
Industrial Sectors ◽  
Weather Stations

Abstract It is a scientifically novel insight to classify the climate of a region using empirical methods together with clustering technique for practical usage in agricultural and industrial sectors. The main objective of this study is to compare the empirical approach to climate classification (Thornthwaite and Mather, De Martonne, the Extended De Martonne and the IRIMO (I.R. of Iran Meteorological Organization)) with clustering technique, Ward’s hierarchical agglomerative method over Iran. The maximum and minimum temperatures and precipitation data of 356 weather stations are used from IRIMO databases. 35 synoptic weather stations are selected for detailed inspection based on appropriate geographical distribution and availability of a continuous 50-year data (1966–2015). Compared with the three empirical reference methods of climate classification, the Thornthwaite and Mather method clearly shows the role of water bodies and air masses for determining the climate type in different regions. This factor is identified as the main advantage of this method over the three others. This superiority is the most visible for the highlands/mountainous regions, in the vicinity of the Zagros Mountains, and in the western regions of Iran. As a case in point, while in the De Martonne and the Extended De Martonne methods, the Zagros storm cell is climatically classified similar to patchy areas in Caspian Sea coastal zone, this cell is correctly identified as a separate zone in the Thornthwaite and Mather method. The results revealed that the clusters obtained from Ward’s algorithm are comparable to those of empirical climate classifications, particularly Thornthwaite and Mather method.

scholarly journals Nine years of UV aerosol optical depth measurements at Thessaloniki, Greece

2007 ◽  
Vol 7 (8) ◽  
pp. 2091-2101 ◽  
Author(s):  
S. Kazadzis ◽  
A. Bais ◽  
V. Amiridis ◽  
D. Balis ◽  
C. Meleti ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Back Trajectories ◽  
Air Masses ◽  
North Eastern ◽  
Range Transport ◽  
Air Quality Monitoring Stations ◽  
Pm 10 ◽  
The City

Abstract. Spectral measurements of the aerosol optical depth (AOD) and the Ångström coefficient were conducted at Thessaloniki, Greece (40.5° N, 22.9° E) between January 1997 and December 2005 with a Brewer MKIII double-monochromator spectroradiometer. The dataset was compared with collocated measurements of a second spectroradiometer (Brewer MKII) and a CIMEL sun-photometer, showing correlations of 0.93 and 0.98, respectively. A seasonal variation of the AOD was observed at Thessaloniki, with AOD values at 340 nm of 0.52 and 0.28 for August and December respectively. Back trajectories of air masses for up to 4 days were used to assess the influence of long-range transport from various regions to the aerosol load over Thessaloniki. It is shown that part of the observed seasonality can be attributed to air masses with high AOD originating from North-Eastern and Eastern directions during summertime. The analysis of the long-term record (9 years) of AOD showed a downward tendency. A similar decreasing tendency was found in the record of the PM$_{10}$ aerosol measurements, which are conducted near the surface at 4 air-quality monitoring stations in the area of the city of Thessaloniki.

scholarly journals First simultaneous measurements of peroxyacetyl nitrate (PAN) and ozone at Nam Co in the central Tibetan Plateau: impacts from the PBL evolution and transport processes

2017 ◽  
Author(s):  
Xiaobin Xu ◽  
Hualong Zhang ◽  
Weili Lin ◽  
Ying Wang ◽  
Shihui Jia
Keyword(s):  
Long Range ◽  
Early Morning ◽  
Diurnal Variations ◽  
Long Range Transport ◽  
Nam Co ◽  
Monsoon Period ◽  
Air Masses ◽  
Upper Troposphere ◽  
Central Tibetan Plateau ◽  
Range Transport

Abstract. Both peroxyacetyl nitrate (PAN) and ozone (O3) are key photochemical products in the atmosphere. Most of the previous in-situ observations of both gases have been made in polluted regions and at low altitude sites. Here we present first simultaneous measurements of PAN and O3 at Nam Co (NMC, 90°57′ E, 30°46′ N, 4745 m  a.s.l.), a remote site in the central Tibetan Plateau (TP). The observations were made during summer periods in 2011 and 2012. The PAN concentrations averaged 0.36 ppb (range: 0.11–0.76 ppb) and 0.44 ppb (range: 0.21–0.99 ppb) during 16–25 August 2011 and 15 May to 13 July 2012, respectively. The O3 concentration varied from 27.9 ppb to 96.4 ppb, with an average of 60.0 ppb. Profound diurnal cycles of PAN and O3 were observed, with minimum values around 05:00 LT, steep rises in the early morning, and broader platforms of high values during 09:00–20:00 LT. We find that the evolution of planetary boundary layer (PBL) played a key role in shaping the diurnal patterns of both gases, particularly the rapid increases of PAN and O3 in the early morning. Air entrainment from the free troposphere into the PBL seemed to cause the early morning increase and be a key factor of sustaining the daytime high concentrations of both gases. The days with higher daytime PBL (about 3 km) showed stronger diurnal variations of both gases and were mainly distributed in the drier pre-monsoon period, while those with shallower daytime PBL (about 2 km) showed minor diurnal variations of both gases and were mainly distributed in the humid monsoon period. Episodes of higher PAN levels were observed occasionally at NMC. These PAN episodes were caused either by rapid downward transport of air masses from the middle/upper troposphere or by long-range transport of PAN plumes from North India. The PAN level in the downward transport cases ranged from 0.5 ppb to 0.7 ppb and may indicate the PAN abundance in the middle/upper troposphere. In the long-range transport case, the PAN level varied in the range of 0.6–1.0 ppb. This long-range transport process influenced most of the western and central TP region for about a week in early June 2012. Our results suggest that polluted air masses from South Asia can significantly enhance the PAN level over the TP. As PAN act as a reservoir of NOx, the impacts of pollution transport from South Asia on tropospheric photochemistry over the TP region deserve further studies.

Radioactivity measurements in the atmosphere and water column of Rogoznica Lake (central Adriatic)

2021 ◽  
Author(s):  
Ivana Tucaković ◽  
Sarah Mateša ◽  
Ivana Coha ◽  
Marija Marguš ◽  
Milan Čanković ◽  
...  
Keyword(s):  
Water Column ◽  
Long Range ◽  
Lake Water ◽  
Dry Deposition ◽  
Long Range Transport ◽  
Atmospheric Input ◽  
Air Masses ◽  
Activity Concentrations ◽  
Range Transport ◽  
Radionuclide Activity

<p>Croatian Science Foundation MARRES project (MARine lake (Rogoznica) as a model for EcoSystem functioning in a changing environment) aims to investigate the unique environment (slow exchange of seawater with the sea; atmospheric input is the only source of freshwater) of the marine lake which is an example of highly stratified (permanent anoxia bellow 9 m depth), and by climate changes affected marine system in the middle of the eastern Adriatic coast (43.53° N, 15.95° E). The area of the lake is characterized by the extensive tourism and mariculture, and the low impact of local industrial activities. It is also affected by the combined influence of long-range transport of air masses and local emissions (open-fire events).</p><p>An important part of the project is focused on the exchange and interaction between atmosphere, water column and sediment by measuring the atmospheric input (wet and dry deposition) of sulphur compounds, organic carbon, trace metals and radionuclides (Be-7, Pb-210).</p><p>This work for the first time will present the current state of the measurements of radioactivity in the Rogoznica lake area, including samples of aerosol particulate matter, PM2.5 < 2.5 um, rainwater and lake water column. Namely, the concentrations of Be-7 and Pb-210 in PM2.5 are measured to determine and correlate the dynamics of particle transport, meteorological information, especially origin of air masses and seasonal variation of PM2.5. While presence of Be-7 indicates the recent wet or dry deposition from the upper parts of the atmosphere, Pb-210 may be used as a tracer for continental air masses. Therefore, it can also indicate the influence of the pollution induced by human activity. Regarding that, special attention will be paid to compare results before and during the Covid-19 lockdown periods.</p><p>So far, preliminary results do not show significant difference in PM2.5 masses and measured radionuclide activity concentrations for the lockdown period. Be-7 and Pb-210 were regularly detected in aerosols collected on a glass fiber filters during a one-week sampling periods with the air flow rate of 2.3 m<sup>3</sup>/h. Their activity concentrations are determined by gamma spectrometry using High Purity Germanium detectors. The results are found to be correlated with PM2.5 masses, ranging from 2.9 to 12.2 Bq/m<sup>3</sup> for Be-7 and from 0.5 to 2.5 Bq/m<sup>3</sup> for Pb-210. First analyses show that the highest values can be related to the long-range transport of air masses and to the recorded near open-fire event. As expected, Be-7 is also detected in almost every rainwater sample (event), with the activity concentration up to 5.6 Bq/L, while low activities of Pb-210 are detected only sporadically. Related to that, Be-7 is detected in lake water column as well, but only in the surface layer and in samples collected during, or immediately after the rain events. </p><p>Dynamics and seasonal variation of radionuclide activity concentrations in here studied samples will be discussed, and the relationships with some meteorological parameters (temperature, wind speed, relative humidity, precipitation level) as well as local and long-range transport and physico-chemical conditions in the lake water column will be established.</p>

scholarly journals Influence of dust and sea-salt sandwich effect on precipitation chemistry over the Western Ghats during summer monsoon

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
L. Yang ◽  
S. Mukherjee ◽  
G. Pandithurai ◽  
V. Waghmare ◽  
P. D. Safai
Keyword(s):  
Summer Monsoon ◽  
High Surface ◽  
Precipitation Chemistry ◽  
Sea Salt ◽  
Monsoon Period ◽  
Air Masses ◽  
Range Transport ◽  
Wind Regimes ◽  
High Uncertainty

AbstractAssessment of Sea Salt (SS) and Non-Sea Salt (NSS) aerosols in rainwater is important to understand the characterization of marine and continental aerosols and their source pathways. Sea salt quantification based on standard seawater ratios are primarily constrained with high uncertainty with its own limitations. Here, by the novelty of k-mean clustering and Positive Matrix Factorization (PMF) analysis, we segregate the air masses into two distinct clusters (oceanic and continental) during summer monsoon period signifying the complex intermingle of sources that act concomitantly. The rainwater composition during strong south-westerly wind regimes (cluster 2-oceanic) was profoundly linked with high sea salt and dust, whereas north-westerly low wind regimes (cluster 1-continental) showed an increase in SO42− and NO3−. However, SO42− abundance over NO3− in rain-water depicted its importance as a major acidifying ion at the region. The satellite-based observations indicate the presence of mid-tropospheric dust at the top (3–5 km) and marine sea salt at bottom acts as a “sandwich effect” for maritime clouds that leads to elevated Ca2+, Na+, Mg2+, and Cl− in rainwater. This characteristic feature is unique as sea spray generation due to high surface winds and dust aloft is only seen during this period. Furthermore, four source factors (secondary inorganic aerosol, mixed dust & sea salt, biomass burning & fertilizer use, and calcium neutralization) derived from PMF analysis showed contribution from local activities as well as long-range transport as dominant sources for the rainwater species.

scholarly journals Oxidation processes in the Eastern Mediterranean atmosphere: Evidence from the Modelling of HO<sub>x</sub> Measurements over Cyprus

2018 ◽  
Author(s):  
Chinmay Mallik ◽  
Laura Tomsche ◽  
Efstratios Bourtsoukidis ◽  
John N. Crowley ◽  
Bettina Derstroff ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Air Masses ◽  
North West ◽  
Sources And Sinks ◽  
Oxidation Processes ◽  
The North ◽  
Range Transport ◽  
The Mediterranean ◽  
Marine Air ◽  
Measurement Location

Abstract. The Mediterranean is a climatically sensitive region located at the crossroads of air masses from three continents: Europe, Africa and Asia. The chemical processing of air masses over this region has implications not only for the air quality, but also for the long-range transport of air pollution. To obtain a comprehensive understanding of oxidation processes over the Mediterranean, atmospheric concentrations of the hydroxyl radical (OH) and the hydroperoxyl radical (HO2) were measured during an intensive field campaign (CYprus PHotochemistry EXperiment, CYPHEX-2014) in the north-west of Cyprus in the summer of 2014. Very low local anthropogenic and biogenic emissions around the measurement location provided a vantage point to study the contrasts in atmospheric oxidation pathways under highly processed marine air masses and those influenced by relatively fresh emissions from mainland Europe. The CYPHEX measurements were used to evaluate OH and HO2 simulations using a photochemical box model (CAABA/MECCA) constrained with CYPHEX observations of O3, CO, NOx, hydrocarbons, peroxides and other major HOx (OH + HO2) sources and sinks in a low NOx environment (

scholarly journals Spatial analysis of air masses backward trajectories in order to identify distant sources of fine particulate matter emission / Analiza przestrzenna wstecznych trajektorii mas powietrza w celu rozpoznania odległych źródeł emisji pyłu drobnego

2015 ◽  
Vol 41 (2) ◽  
pp. 28-35 ◽  
Author(s):  
Jolanta Godłowska ◽  
Monika J. Hajto ◽  
A. Monika Tomaszewska
Keyword(s):  
Particulate Matter ◽  
Spatial Analysis ◽  
Fine Particulate Matter ◽  
Emission Sources ◽  
Air Masses ◽  
Backward Trajectories ◽  
Particulate Matter Emission ◽  
Aggregate Information ◽  
Fine Particulate ◽  
The Impact

Abstract The paper presents a method of identifying distant emission sources of fine particulate matter PM2.5 affecting significantly PM2.5 concentrations at a given location. The method involves spatial analysis of aggregate information about PM2.5 concentrations measured at the location and air masses backward trajectories calculated by HYSPLIT model. The method was examined for three locations of PM2.5 measurement stations (Diabla Góra, Gdańsk, and Katowice) which represented different environmental conditions. The backward trajectories were calculated starting from different heights (30, 50, 100 and 150 m a. g. l.). All points of a single backward trajectory were assigned to the PM2.5 concentration corresponding to the date and the site of the beginning of trajectory calculation. Daily average concentrations of PM2.5 were used, and in the case of Gdańsk also hourly ones. It enabled to assess the effectiveness of the presented method using daily averages if hourly ones were not available. Locations of distant sources of fine particulate matter emission were determined by assigning to each grid node a mean value of PM2.5 concentrations associated with the trajectories points located within the so-called search ellipse. Nearby sources of fine particulate matter emission were eliminated by filtering the trajectories points located close to each other (so-called duplicates). The analyses covered the period of January-March 2010. The results indicated the different origin of air masses in the northern and southern Poland. In Diabla Góra and Gdańsk the distant sources of fine particulate matter emission are identified in Belarus and Russia. In Katowice the impact of the Belarusian PM2.5 emission sources was also noted but as the most important fine particulate matter emission sources were considered those located in the area of Romania, Hungary, Slovakia and Ukraine.

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