scholarly journals Seasonal variations in the synoptic climatology of air pollution in Birmingham, UK

2021 ◽  
Author(s):  
Edward C. Hodgson ◽  
Ian D. Phillips
Keyword(s):  
Principal Component ◽  
Cold Season ◽  
Meteorological Conditions ◽  
Synoptic Climatology ◽  
Air Mass ◽  
Pollutant Concentrations ◽  
High Concentrations ◽  
Air Mass Types ◽  
Temperature Inversions ◽  
Pollution Episodes

AbstractA synoptic typing approach was undertaken to examine the seasonal relationship (winter versus summer) between air mass types and pollutant concentrations of O3, PM10, NOx, NO2 and CO in Birmingham, UK, from 2000 to 2015. Daily means of seven surface meteorological variables were entered into a P-mode principal component analysis. Three principal components explained 72.2% (72.9%) of the variance in winter (summer). Cluster analysis was used to group together days with similar PC scores and thus similar meteorological conditions. Six clusters provided the best air mass classification in both seasons. High pollutant concentrations were associated with anticyclonic types. In particular, tropical (polar) continental air mass type was most likely to produce extremely high concentrations in summer (winter). In winter, a sequence of Polar Continental (cool and humid) and Binary Mid-latitude Anticyclonic Maritime—Sub-Polar Cyclonic Maritime (cold and dry) induced severe pollution episodes in all pollutants. Whilst the mean duration of severe pollution episodes varied little between winter and summer (O3 was an exception, with severe episodes lasting 20% longer in summer), high pollutant extremes were more common in winter. This was due to more favourable meteorological conditions (e.g. temperature inversions) and increased anthropogenic emissions during the cold season.

scholarly journals Seasonal Variations in the Synoptic Climatology of Air Pollution in Birmingham, United Kingdom

2021 ◽  
Author(s):  
EDWARD C HODGSON ◽  
Ian Douglas Phillips
Keyword(s):  
United Kingdom ◽  
Principal Component ◽  
Cold Season ◽  
Meteorological Conditions ◽  
Synoptic Climatology ◽  
Air Mass ◽  
Pollutant Concentrations ◽  
High Concentrations ◽  
Air Mass Types ◽  
Pollution Episodes

Abstract A synoptic typing approach was undertaken to examine the seasonal relationship (winter versus summer) between air mass types and pollutant concentrations of O 3 , PM10, NO x , NO 2 and CO in Birmingham, United Kingdom from 2000 to 2015. Daily means of seven surface meteorological variables were entered into a P-mode principal component analysis. Three principal components explained 72.2% (72.9%) of the variance in winter (summer). Cluster analysis was used to group together days with similar PC scores and thus homogeneous meteorological conditions. Six clusters provided the best air mass classification in both seasons. High pollutant concentrations were associated with anticyclonic types. In particular, tropical (polar) continental air mass type was most likely to produce extremely high concentrations in summer (winter). In winter, a sequence of Polar Continental (cool and humid) and Binary Mid-latitude Anticyclonic Maritime – Sub-Polar Cyclonic Maritime (cold and dry) induced severe pollution episodes in all pollutants. Whilst the mean duration of severe pollution episodes varied little between winter and summer (O 3 was an exception, with severe episodes lasting 20% longer in summer), high pollutant extremes were more common in winter. This was due to more favourable meteorological conditions (e.g., temperature inversions) and increased anthropogenic emissions during the cold season.

scholarly journals Lidar detection of high concentrations of ozone and aerosol transported from Northeast Asia over Saga, Japan

2016 ◽  
Author(s):  
Osamu Uchino ◽  
Tetsu Sakai ◽  
Toshiharu Izumi ◽  
Tomohiro Nagai ◽  
Isamu Morino ◽  
...  
Keyword(s):  
Tropospheric Ozone ◽  
Climate Model ◽  
Vertical Mixing ◽  
Northeast Asia ◽  
Mixing Ratio ◽  
Air Mass ◽  
Meteorological Research Institute ◽  
Pollutant Concentrations ◽  
High Concentrations ◽  
Physical And Chemical

Abstract. To validate products of the Greenhouse gases Observing SATellite (GOSAT), we observed vertical profiles of aerosols, thin cirrus clouds, and tropospheric ozone with a mobile lidar system that consisted of a two-wavelength (532 and 1064 nm) polarization lidar and a tropospheric ozone Differential Absorption Lidar (DIAL). We used these lidars to make continuous measurements over Saga (33.24° N, 130.29° E) during 20–31 March 2015. High ozone and high aerosol concentrations were observed almost simultaneously in the altitude range 0.5–1.5 km from 03:00 to 20:00 Japan Standard Time on 22 March 2015. The maximum ozone volume mixing ratio was ~ 110 ppbv. The maxima of the aerosol extinction coefficient and optical depth at 532 nm were 1.2 km−1 and 2.1, respectively. Backward trajectory analysis indicated that an air mass with high ozone and aerosol concentrations could have been transported from Northeast Asia. Based on the lidar data and the ground-based in-situ measurements at Saga, this air mass could have been transported to the surface by vertical mixing when the planetary boundary layer developed in the daytime. This plume, which contained high ozone and aerosol pollutant concentrations, impacted surface air quality substantially. After some modifications of its physical and chemical parameters, the Meteorological Research Institute Chemistry-Climate Model, version 2 (MRI-CCM2) approximately reproduced the high-ozone volume-mixing ratio. The Model of Aerosol Species IN the Global AtmospheRe (MASINGAR) mk-2 successfully predicted high aerosol concentrations, but the predicted peak aerosol optical thickness was about one-third of the observed value.

scholarly journals Classification of Clouds Sampled at the Puy de Dôme Station (France) Based on Chemical Measurements and Air Mass History Matrices

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 732
Author(s):  
Pascal Renard ◽  
Angelica Bianco ◽  
Jean-Luc Baray ◽  
Maxime Bridoux ◽  
Anne-Marie Delort ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Principal Component ◽  
Cloud Microphysics ◽  
Back Trajectory ◽  
Air Mass ◽  
Air Masses ◽  
Chemical Measurements ◽  
History Of ◽  
High Concentrations ◽  
The Impact

A statistical analysis of 295 cloud samples collected at the Puy de Dôme station in France (PUY), covering the period 2001–2018, was conducted using principal component analysis (PCA), agglomerative hierarchical clustering (AHC), and partial least squares (PLS) regression. Our model classified the cloud water samples on the basis of their chemical concentrations and of the dynamical history of their air masses estimated with back-trajectory calculations. The statistical analysis split our dataset into two sets, i.e., the first set characterized by westerly air masses and marine characteristics, with high concentrations of sea salts and the second set having air masses originating from the northeastern sector and the “continental” zone, with high concentrations of potentially anthropogenic ions. It appears from our dataset that the influence of cloud microphysics remains minor at PUY as compared with the impact of the air mass history, i.e., physicochemical processes, such as multiphase reactivity.

Piper nigrum Oil – Determination of Selected Terpenes for Quality Evaluation

Planta Medica ◽  
2018 ◽  
Vol 85 (03) ◽  
pp. 185-194 ◽  
Author(s):  
Mei Wang ◽  
Amar Chittiboyina ◽  
Jon Parcher ◽  
Zulfiqar Ali ◽  
Paul Ford ◽  
...  
Keyword(s):  
Quality Evaluation ◽  
Geographical Location ◽  
Chemical Characterization ◽  
Principal Component ◽  
Cost Effective ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Ms Analysis ◽  
Chemical Profiles ◽  
High Concentrations

AbstractThe growing demand and commercial value of black pepper (Piper nigrum) has resulted in considerable interest in developing suitable and cost-effective methods for chemical characterization and quality evaluation purposes. In the current study, an extensive set of oil samples (n = 23) that were extracted by steam distillation from black pepper seeds was investigated to compare the chemical profiles of samples originating from nine major producing countries, as well as to identify potential chemical markers for quality evaluation. The twenty-two most abundant volatile compounds, mainly terpenes, in these oils were determined by conventional GC/MS analysis. Principal component analysis with this set of data revealed distinct clusters for samples that originated from China and Malaysia. Relatively low concentrations of sabinene (< 0.2%) and high concentrations of 3-carene (10.9 – 21.1%) were observed in these samples, respectively, compared to oil samples from other countries. The enantiomeric distributions of key terpene markers, viz., β-pinene, sabinene, limonene, and terpinen-4-ol, were determined by chiral GC/MS analysis. Interestingly, for these four monoterpenes, levo-isomers were found to be predominant, emphasizing the highly conserved enzymatic processes occurring in P. nigrum. Moreover, consistent enantiomeric ratios ((−) isomer/(+) isomer) of 92.2 ± 3.0% for β-pinene, 94.8 ± 2.8% for sabinene, 60.7 ± 1.1% for limonene, and 78.3 ± 1.3% for terpinen-4-ol were observed, independent of geographical location. These results demonstrate the potential of using stereospecific compositions as chiral signatures for establishing the authenticity and quality of black pepper oil.

scholarly journals On the multiday haze in the Asian continental outflow: the important role of synoptic conditions combined with regional and local sources

2017 ◽  
Vol 17 (15) ◽  
pp. 9311-9332 ◽  
Author(s):  
Jihoon Seo ◽  
Jin Young Kim ◽  
Daeok Youn ◽  
Ji Yi Lee ◽  
Hwajin Kim ◽  
...  
Keyword(s):  
Meteorological Factors ◽  
Early Stage ◽  
Meteorological Conditions ◽  
The Yellow Sea ◽  
Regional Transport ◽  
Local Sources ◽  
Haze Episode ◽  
High Concentrations ◽  
Continental Outflow ◽  
Local Emissions

Abstract. The air quality of the megacities in populated and industrialized regions like East Asia is affected by both local and regional emission sources. The combined effect of regional transport and local emissions on multiday haze was investigated through a synthetic analysis of PM2. 5 sampled at both an urban site in Seoul, South Korea and an upwind background site on Deokjeok Island over the Yellow Sea during a severe multiday haze episode in late February 2014. Inorganic components and carbonaceous species of daily PM2. 5 samples were measured, and gaseous pollutants, local meteorological factors, and synoptic meteorological conditions were also determined. A dominance of fine-mode particles (PM2. 5 ∕ PM10  ∼  0.8), a large secondary inorganic fraction (76 %), high OC ∕ EC (> 7), and highly oxidized aerosols (oxygen-to-carbon ratio of  ∼  0.6 and organic-mass-to-carbon ratio of  ∼  1.9) under relatively warm, humid, and stagnant conditions characterize the multiday haze episode in Seoul; however, the early and late stages of the episode show different chemical compositions of PM2. 5. High concentrations of sulfate in both Seoul and the upwind background in the early stage suggest a significant regional influence on the onset of the multiday haze. At the same time, high concentrations of nitrate and organic compounds in Seoul, which are local and highly correlated with meteorological factors, suggest the contribution of local emissions and secondary formation under stagnant meteorological conditions to the haze. A slow eastward-moving high-pressure system from southern China to the East China Sea induces the regional transport of aerosols and potential gaseous precursors for secondary aerosols from the North China Plain in the early stage but provides stagnant conditions conducive to the accumulation and the local formation of aerosols in the late stage. A blocking ridge over Alaska that developed during the episode hinders the zonal propagation of synoptic-scale systems and extends the haze period to several days. This study provides chemical insights into haze development sequentially by regional transport and local sources, and shows that the synoptic condition plays an important role in the dynamical evolution of long-lasting haze in the Asian continental outflow region.

scholarly journals Recycling and Conversion of Yeasts into Organic Nitrogen Sources for Wine Fermentation: Effects on Molecular and Sensory Attributes

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 313
Author(s):  
Paula Rojas ◽  
Daniel Lopez ◽  
Francisco Ibañez ◽  
Camila Urbina ◽  
Wendy Franco ◽  
...  
Keyword(s):  
Organic Nitrogen ◽  
Protein Hydrolysate ◽  
Principal Component ◽  
Nitrogen Sources ◽  
Isoamyl Alcohol ◽  
Positive Influence ◽  
Higher Alcohols ◽  
Fermentation Performance ◽  
High Concentrations ◽  
Significant Positive Influence

Organic nitrogen plays a significant role in the fermentation performance and production of esters and higher alcohols. This study assessed the use of yeast protein hydrolysate (YPH) as a nitrogen source for grape must fermentation. In this study, we prepared an enzymatic protein hydrolysate using yeasts recovered from a previous fermentation of wine. Three treatments were performed. DAP supplementation was used as a control, while two YPH treatments were used. Low (LDH) and high degrees of hydrolysis (HDH), 3.5% and 10%, respectively, were chosen. Gas chromatography and principal component analysis indicated a significant positive influence of YPH-supplementations on the production of esters and higher alcohols. Significantly high concentrations of 3-methyl-1-penthanol, isoamyl alcohol, isobutanol, and 2-phenylethanol were observed. Significant odorant activity was obtained for 3-methyl-1-pentanol and ethyl-2-hexenoate. The use of YPH as nitrogen supplementation is justified as a recycling yeasts technique by the increase in volatile compounds.

scholarly journals Wintertime Arctic Air Pollution over central Alaska: pre-ALPACA campaign

2021 ◽  
Author(s):  
Eleftherios Ioannidis ◽  
Kathy S. Law ◽  
Jean-Christophe Raut ◽  
Tatsuo Onishi ◽  
Louis Marelle ◽  
...  
Keyword(s):  
Air Pollution ◽  
The United States ◽  
Point Sources ◽  
The Arctic ◽  
Formation Mechanisms ◽  
Winter Conditions ◽  
Local Point ◽  
Temperature Inversions ◽  
Local Emissions ◽  
Pollution Episodes

&lt;p&gt;The wintertime Arctic is influenced by air pollution transported from mid-latitudes, leading to formation of Arctic Haze, as well as local emissions such as combustion for heating and power production in very cold winter conditions. This contributes to severe air pollution episodes, with enhanced aerosol concentrations, inter-dispersed with cleaner periods. However, the formation of secondary aerosol particles (sulphate, organics, nitrate) in cold/dark wintertime Arctic conditions, which could contribute to these pollution episodes, is poorly understood.&lt;/p&gt;&lt;p&gt;In this study, which contributes to the Air Pollution in the Arctic: Climate, Environment and Societies - Alaskan Layered Pollution and Arctic Chemical Analysis (PACES-ALPACA) initiative, the Weather Research Forecasting Model with chemistry (WRF-Chem) is used to investigate wintertime pollution over central Alaska focusing on the Fairbanks region, during the pre-ALPACA campaign in winter 2019-2020. Fairbanks is the most polluted city in the United States during wintertime, due to high local emissions and the occurrence of strong surface temperature inversions trapping pollutants near the surface.&lt;/p&gt;&lt;p&gt;Firstly, different WRF meteorological and surface schemes were tested over Alaska with a particular focus on improving simulations of the wintertime boundary layer structure including temperature inversions. An optimal WRF set-up, with increased vertical resolution below 2km, was selected based on evaluation against available data.&lt;/p&gt;&lt;p&gt;Secondly, a quasi-hemispheric WRF-Chem simulation, using the improved WRF setup, was used to assess large-scale synoptic conditions and to evaluate background aerosols originating from remote anthropogenic and natural sources affecting central Alaska during the campaign. The model was run with Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants (ECLIPSE) v6b anthropogenic emissions and improved sea-spray aerosol emissions. Discrepancies in modelled aerosols compared available data are being investigated (e.g. missing dark formation mechanisms, treatment of removal processes).&lt;/p&gt;&lt;p&gt;Thirdly, fine resolution simulations, using high resolution emissions (e.g. 2019 CAMS inventory), including local point sources, over the Fairbanks region, were used to investigate chemical and dynamical processes influencing aerosols under different meteorological conditions observed during the field campaign including a cold stable episode and a period with possible mixing of air masses from aloft. The model was evaluated against available aerosol, oxidant (ozone) and aerosol precursor data from surface monitoring sites and collected during the pre-campaign, including vertical profile data collected in the lowest 20m. The sensitivity of modelled aerosols to meteorological factors, such as relative humidity, temperature gradients and vertical mixing under winter conditions are investigated.&lt;/p&gt;

scholarly journals A foehn-induced haze front in Beijing: observations and implications

2020 ◽  
Author(s):  
Ju Li ◽  
Zhaobin Sun ◽  
Donald H. Lenschow ◽  
Mingyu Zhou ◽  
Youjun Dou ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Surface Wind ◽  
Layer Growth ◽  
Air Mass ◽  
Pollutant Concentrations ◽  
Clean Air ◽  
Particulate Concentration ◽  
Weak Pressure Gradient ◽  
Bth Region

Abstract. Despite frequent foehns in the Beijing–Tianjin–Hebei (BTH) region, there are only a few studies of their effects on air pollution in this region, or elsewhere. Here, we discuss a foehn-induced haze front (HF) event using observational data to document its structure and evolution. Using a dense network of comprehensive measurements in the BTH region, our analyses indicate that the foehn played an important role in the formation of the HF with significant impacts on air pollution. Northerly warm–dry foehn winds, with low particulate concentration in the northern area, collided with a cold–wet polluted air mass to the south and formed an HF in the urban area. The HF, which is associated with a surface wind convergence line and distinct contrasts of temperatures, humidity and pollutant concentrations, resulted in an explosive growth of particulate concentration. As the plains-mountain wind circulation was overpowered by the foehn, a weak pressure gradient due to the different air densities between air masses was the main factor forcing advances of the polluted air mass into the clean air mass, resulting in severe air pollution over the main urban areas. Our results show that the foehn can affect air pollution through two effects: direct wind transport of air pollutants, and altering the air mass properties to inhibit boundary-layer growth and thus indirectly aggravating air pollution. This study highlights the need to further investigate the foehn and its impacts on air pollution in the BTH region.

scholarly journals Physical, chemical and mineralogical attributes of a representative group of soils from the Eastern Amazon, Brazil

2018 ◽  
Author(s):  
Edna Santos de Souza ◽  
Antonio Rodrigues Fernandes ◽  
Anderson Martins de Souza Braz ◽  
Fábio Júnior de Oliveira ◽  
Luís Reynaldo Ferracciú Alleoni ◽  
...  
Keyword(s):  
Descriptive Analysis ◽  
Sustainable Use ◽  
Ammonium Oxalate ◽  
Principal Component ◽  
Sodium Dithionite ◽  
Physical Chemical ◽  
Low Concentrations ◽  
High Concentrations ◽  
And Cluster Analysis ◽  
Al Oxide

Abstract. Amazonian soils are heterogeneous. However, few studies have been carried out in the Amazon, mainly because of its considerable size, which complicates the collection of data and the ability to plan for the sustainable use of natural resources. In this study, the physical, chemical and mineralogical attributes of soils in the state of Pará, Brazil, were characterized by examining particle size, fertility, silicon (Si) extracted by sodium hydroxide (NaOH), and iron (Fe), aluminum (Al), and manganese (Mn) extracted by sulfuric acid (H2SO4), sodium dithionite-citrate-bicarbonate and ammonium oxalate + oxalic acid. Descriptive analysis, multivariate principal component analysis and cluster analysis were carried out. The soils had low concentrations of bioavailable P, Ca2+, Mg2+ and K+ and high concentrations of Al3+ and Si and Al oxide contents were higher in Cambisols. Contents of Fe and Mn oxides were higher in both Cambisols and Nitosols, which are rich in oxidic minerals. Multivariate analysis indicated an association between the content of organic carbon and the pH, P, Ca, Mg and K contents. An additional association was observed between clay, potential acidity and the Fe and Al oxide contents.

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