scholarly journals Contribution of anthropogenic and natural sources in PM10 during North African dust events in Southern Europe

2021 ◽  
Vol 290 ◽  
pp. 118065
Author(s):  
María Millán-Martínez ◽  
Daniel Sánchez-Rodas ◽  
Ana M. Sánchez de la Campa ◽  
Jesús de la Rosa
Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1090
Author(s):  
Raquel Fernandes ◽  
Marcelo Fragoso

Heatwaves are an extreme meteorological event in which affected populations may also be exposed to deteriorated air quality conditions due to the increase in air pollutant concentrations, such as PM10 (particulate matter < 10 µg/m3). In order to identify heatwaves (1973–2019) in the region of Faro (Algarve) during the hot season (April–September), the Excess Heat Factor (EHF) index was applied. The Mann–Kendall test revealed an upward trend in three heatwave metrics in Faro, and the trend of accumulated heat load (EHF load) was also positive as would be expected, but its signal was not statistically significant. An inventory of North African dust events (2006–2019) was made, and their simultaneous occurrence with heatwaves was assessed, pointing to only 20% of dust events of the Sahara occurring simultaneously with heatwave days. A cluster analysis was conducted on daily geopotential height fields at 850 hPa level over the 2006–2019 period, and four distinct patterns were identified as the most prominent synoptic circulations promoting both heatwave conditions and North African dust over the Algarve.


2021 ◽  
Vol 9 (03) ◽  
pp. 509-526
Author(s):  
Alioune Marone ◽  
◽  
Malick Mbengue ◽  
Gregory Jenkins ◽  
Demba Ndao Niang ◽  
...  

Previous work in the Caribbean and West Africa have shown that air samples taken during dust events contain microorganisms (bacteria, fungi, viruses), including human pathogens that can cause many respiratory diseases. To better understand the potential downstream effect of bacteria dust on human health and public ecosystems, it is important to characterize the source population. In this study, we aimed to explore the bacterial populations of African dust samples collected between 2013-2017. The dust samples were collected using the spatula method, then the hypervariable regions (V3 and V4) of the 16S rRNA gene were amplified using PCR followed byMiSeq Illumina sequencing. Analysis of the sequencing data were performed using MG-RAST. At the phylum level, the proportions of Actinobacteria (22%), Firmicutes (20%), Proteobacteria (19%), and Bacteroidetes (13%) were respectively predominant in all dust samples. At the genus level, Bacillus(16%), Pseudomonas(10%), Nocardiodes and Exiguobacterium (5%) are the most dominated genera in African dust samples collected in this study.The study showed that molecular characterization of dust microbial population remains a very efficient method, also applicable to the search for viruses and fungi in this type of sample. It is important to note that the majority of microorganisms identified in this study can cause respiratory diseases.


2021 ◽  
Vol 554 ◽  
pp. 116645
Author(s):  
Amy M. Jewell ◽  
Nick Drake ◽  
Anya J. Crocker ◽  
Natalie L. Bakker ◽  
Tereza Kunkelova ◽  
...  

1997 ◽  
Vol 102 (D10) ◽  
pp. 11225-11238 ◽  
Author(s):  
Kevin D. Perry ◽  
Thomas A. Cahill ◽  
Robert A. Eldred ◽  
Dabrina D. Dutcher ◽  
Thomas E. Gill

2009 ◽  
Vol 3 (1) ◽  
pp. 59-62 ◽  
Author(s):  
K. N. Grigoropoulos ◽  
P. T. Nastos ◽  
G. Ferentinos

Abstract. The objective of this study is to present and analyse the spatial distribution of PM1 (particulate matter with diameter less than 1 μm) and PM10 (particulate matter with diameter less than 10 μm) within the greater area of Athens (GAA), Greece, during two extreme Saharan dust episodes in 2006 and 2008. Two portable detectors, based on light scattering method, were used to record the particulate matter concentrations. The samples were collected in the same morning hour of the day which coincided with the peak of vehicles traffic. We analysed the recorded data on normal days and on days with extreme Saharan dust events in order to find out the exceedances of the particulate matter concentrations. Using Kriging method, the spatial patterns of PM1 and PM10 concentrations were constructed for GAA. It is already known that particulate matter represent the main hazard in cardiovascular and respiratory syndromes within the most polluted cities of Europe, which confront high traffic problems, amplified by Saharan dust episodes, which are frequent especially in the Southern Europe, during spring time. The results of the performed analysis showed that during these episodes, PM concentrations over exceed the thresholds set by the European Union, exacerbating the human health in Athens.


2020 ◽  
Vol 20 (16) ◽  
pp. 10047-10062 ◽  
Author(s):  
Samantha J. Kramer ◽  
Claudia Alvarez ◽  
Anne E. Barkley ◽  
Peter R. Colarco ◽  
Lillian Custals ◽  
...  

Abstract. North African dust reaches the southeastern United States every summer. Size-resolved dust mass measurements taken in Miami, Florida, indicate that more than one-half of the surface dust mass concentrations reside in particles with geometric diameters less than 2.1 µm, while vertical profiles of micropulse lidar depolarization ratios show dust reaching above 4 km during pronounced events. These observations are compared to the representation of dust in the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) aerosol reanalysis and closely related Goddard Earth Observing System model version 5 (GEOS-5) Forward Processing (FP) aerosol product, both of which assimilate satellite-derived aerosol optical depths using a similar protocol and inputs. These capture the day-to-day variability in aerosol optical depth well, in a comparison to an independent sun-photometer-derived aerosol optical depth dataset. Most of the modeled dust mass resides in diameters between 2 and 6 µm, in contrast to the measurements. Model-specified mass extinction efficiencies equate light extinction with approximately 3 times as much aerosol mass, in this size range, compared to the measured dust sizes. GEOS-5 FP surface-layer sea salt mass concentrations greatly exceed observed values, despite realistic winds and relative humidities. In combination, these observations help explain why, despite realistic total aerosol optical depths, (1) free-tropospheric model volume extinction coefficients are lower than those retrieved from the micro-pulse lidar, suggesting too-low model dust loadings in the free troposphere, and (2) model dust mass concentrations near the surface can be higher than those measured. The modeled vertical distribution of dust, when captured, is reasonable. Large, aspherical particles exceeding the modeled dust sizes are also occasionally present, but dust particles with diameters exceeding 10 µm contribute little to the measured total dust mass concentrations after such long-range transport. Remaining uncertainties warrant a further integrated assessment to confirm this study's interpretations.


2020 ◽  
Author(s):  
Samantha J. Kramer ◽  
Claudia Alvarez ◽  
Anne Barkley ◽  
Peter R. Colarco ◽  
Lillian Custals ◽  
...  

Abstract. North African dust reaches the southeast United States every summer. Measurements taken in Miami, Florida indicate that more than one-half of the surface dust mass concentrations reside in particles with diameters less than 2.1 μm, while vertical profiles of micropulse lidar depolarization ratios show dust reaching above four km during pronounced events. These observations are compared to the representation of dust in the MERRA-2 aerosol reanalysis and closely-related GEOS-5 Forward Processing (FP) aerosol product, both of which assimilate satellite-derived aerosol optical depths using a similar protocol and inputs. These capture the day-to-day variability in aerosol optical depth well, in a comparison to an independent sun-photometer-derived aerosol optical depth dataset. Measured near-surface dust mass concentrations slightly exceed model values, with most of the modeled dust mass in diameters between 2–6 μm. Modeled-specified mass extinction efficiencies equate light extinction with approximately three times as much aerosol mass, in this size range, compared to the measured dust sizes. GEOS-5 FP surface-layer sea salt mass concentrations greatly exceed observed values, despite realistic winds and relative humidities. In combination, these observations help explain, why, despite realistic total aerosol optical depths, 1) free-tropospheric model volume extinction coefficients are lower than those retrieved from the micro-pulse lidar, suggesting too low model dust loadings, and 2) model dust mass concentrations near the surface are higher than those measured. The modeled vertical distribution of dust, when captured, is reasonable. Large, aspherical particles exceeding the modeled dust sizes are also occasionally present, but dust particles with diameters exceeding ten μm contribute little to the measured total dust mass concentrations after such long-range transport. A further integrated assessment is needed to confirm this study's interpretations.


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