Aerosol Nitrate and Non-Sea-Salt Sulfate Over the Eastern Mediterranean

2000 ◽  
pp. 743-744
Author(s):  
Türkan Özsoy ◽  
Cemal Saydam ◽  
Nilgün Kubilay ◽  
Oya B. Nalçaci ◽  
İlkay Salihoğlu
Keyword(s):  
Eastern Mediterranean ◽  
Sea Salt

scholarly journals An integrated modeling study on the effects of mineral dust and sea salt particles on clouds and precipitation

2010 ◽  
Vol 10 (10) ◽  
pp. 23959-24014 ◽  
Author(s):  
S. Solomos ◽  
G. Kallos ◽  
J. Kushta ◽  
M. Astitha ◽  
C. Tremback ◽  
...  
Keyword(s):  
Air Quality ◽  
Mineral Dust ◽  
Eastern Mediterranean ◽  
Atmospheric Modeling ◽  
Sea Salt ◽  
Cloud Formation ◽  
Dust Particles ◽  
Limited Area ◽  
Aerosol Cloud ◽  
Climate Interactions

Abstract. The amount of airborne particles that will nucleate and form cloud droplets under specific atmospheric conditions, depends on their number concentration, size distribution and chemical composition. Aerosol is affected by primary particle emissions, gas-phase precursors, their transformation and interaction with atmospheric constituents, clouds and dynamics. A comprehensive assessment of these interactions requires an integrated approach; most studies however decouple aerosol processes from cloud and atmospheric dynamics and cannot account for all the feedbacks involved in aerosol-cloud-climate interactions. This study addresses aerosol-cloud-climate interactions with the Integrated Community Limited Area Modeling System (ICLAMS) that includes online parameterization of the physical and chemical processes between air quality and meteorology. ICLAMS is an extended version of the Regional Atmospheric Modeling System (RAMS) and it has been designed for coupled air quality – meteorology studies. Model sensitivity tests for a single-cloud study as well as for a case study over the Eastern Mediterranean illustrate the importance of aerosol properties in cloud formation and precipitation. Mineral dust particles are often coated with soluble material such as sea-salt, thus exhibiting increased CCN efficiency. Increasing the percentage of salt-coated dust particles by 15% in the model resulted in more vigorous convection and more intense updrafts. The clouds that were formed extended about 3 km higher and the initiation of precipitation was delayed by one hour. Including on-line parameterization of the aerosol effects improved the model bias for the twenty-four hour accumulated precipitation by 7%. However, the spatial distribution and the amounts of precipitation varied greatly between the different aerosol scenarios. These results indicate the large portion of uncertainty that remains unresolved and the need for more accurate description of aerosol feedbacks in atmospheric models and climate change predictions.

scholarly journals Aerosol sources and their contribution to the chemical composition of aerosols in the Eastern Mediterranean Sea during summertime

2002 ◽  
Vol 2 (5) ◽  
pp. 1287-1315 ◽  
Author(s):  
J. Sciare ◽  
H. Bardouki ◽  
C. Moulin ◽  
N. Mihalopoulos
Keyword(s):  
Chemical Composition ◽  
Mediterranean Sea ◽  
Central Europe ◽  
Eastern Mediterranean ◽  
Sea Salt ◽  
Anthropogenic Emissions ◽  
Eastern Mediterranean Sea ◽  
Air Masses ◽  
Wide Range ◽  
Aerosol Sources

Abstract. A detailed study on the temporal variability of compounds important in controlling aerosol chemical composition was performed during a one-month experiment conducted during summer 2000 at a background site on Crete, in the Eastern Mediterranean Sea. Contribution of different aerosol sources in the Eastern Mediterranean Basin could be investigated at this location since the site is influenced by a wide range of air masses originating mainly in Europe and Africa. Chemical apportionment was performed for various air mass origins and showed a strong impact of anthropogenic emissions in the Turkey and Central Europe sectors, with black carbon (BC) and non-sea-salt sulfate (nss-SO4) concentrations being almost a factor of two higher than observed in the Eastern and Western Europe sectors. High levels of non-sea-salt calcium (nss-Ca) were associated with air masses from Africa but also from Central Turkey. Evidence was found that BC calculation based on light absorbance during dust events was biased. A source-oriented model was applied for these compounds as well as for sulfur dioxide (SO2), in order to examine the source-receptor relationships responsible for the observed levels in Crete. Among the results obtained from this model, the major contribution of Turkey and Central Europe was confirmed in terms of anthropogenic emissions. Comparisons with remote optical properties obtained from Satellite observations (SEAWIFS) north of Crete indicates that our ground based aerosol characterization was suitable for describing aerosol properties in the atmospheric column for most of the time during the campaign.

scholarly journals Fine particle pH and gas-particle phase partitioning of inorganic species in Pasadena, California, during the 2010 CalNex campaign

2017 ◽  
Author(s):  
Hongyu Guo ◽  
Jiumeng Liu ◽  
Karl Froyd ◽  
James M. Robert ◽  
Patrick R. Veres ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Fine Particle ◽  
Eastern Mediterranean ◽  
Sea Salt ◽  
Phase Partitioning ◽  
Complex Interactions ◽  
Southeastern Us ◽  
Internal Mixing ◽  
Inorganic Species ◽  
Nitrate Concentrations

Abstract. pH is a fundamental aerosol property that affects ambient particle concentration and composition, linking pH to all aerosol environmental impacts. Here, PM1 and PM2.5 pH are calculated based on data from measurements during the California Research at the Nexus of Air Quality and Climate Change (CalNex) study from 15 May to 15 June 2010 in Pasadena CA. Particle pH and water were predicted with the ISORROPIA-II thermodynamic model and validated by comparing predicted to measured gas-particle partitioning of inorganic nitrate, ammonium and chloride. The study mean ± standard deviation PM1 pH was 1.9 ± 0.5 for the SO42−-NO3−-NH4+-HNO3-NH3 system. For PM2.5, internal mixing of sea salt components (SO42−-NO3−-NH4+-Na+-Cl−-K+-HNO3-NH3-HCl system) raised the bulk pH to 2.7 ± 0.3 and improved predicted nitric acid partitioning with PM2.5 components. The results show little effect of sea salt on PM1 pH, but significant effects on PM2.5 pH. A mean PM1 pH of 1.9 at Pasadena was approximately one unit higher than what we have reported in the southeastern US, despite similar temperature, relative humidity and sulfate ranges and is due to higher total nitrate concentrations (nitric acid plus nitrate) relative to sulfate, a situation where particle water is affected by semi-volatile nitrate concentrations. Under these conditions nitric acid partitioning can further promote nitrate formation by increasing aerosol water, which raises pH by dilution, further increasing nitric acid partitioning and resulting in a significant increase in fine particle nitrate and pH. This study provides insights on the complex interactions between particle pH and nitrate in a summertime coastal environment and a contrast to recently reported pH in the eastern US in summer and winter and the eastern Mediterranean. All studies have consistently found highly acidic PM1 with pH generally below 3.

scholarly journals AIRUSE-LIFE +: estimation of natural source contributions to urban ambient air PM<sub>10</sub> and PM<sub>2. 5</sub> concentrations in southern Europe – implications to compliance with limit values

2017 ◽  
Vol 17 (5) ◽  
pp. 3673-3685 ◽  
Author(s):  
Evangelia Diapouli ◽  
Manousos I. Manousakas ◽  
Stergios Vratolis ◽  
Vasiliki Vasilatou ◽  
Stella Pateraki ◽  
...  
Keyword(s):  
Forest Fires ◽  
Seasonal Variability ◽  
Urban Areas ◽  
Eastern Mediterranean ◽  
Ambient Air ◽  
Sea Salt ◽  
Limit Values ◽  
Natural Sources ◽  
Life Project ◽  
African Dust

Abstract. The contribution of natural sources to ambient air particulate matter (PM) concentrations is often not considered; however, it may be significant for certain areas and during specific periods of the year. In the framework of the AIRUSE-LIFE+ project, state-of-the-art methods have been employed for assessing the contribution of major natural sources (African dust, sea salt and forest fires) to PM concentrations, in southern European urban areas. 24 h measurements of PM10 and PM2. 5 mass and chemical composition were performed over the course of a year in five cities: Porto, Barcelona, Milan, Florence and Athens. Net African dust and sea-salt concentrations were calculated based on the methodologies proposed by the EC (SEC 2011/208). The contribution of uncontrolled forest fires was calculated through receptor modelling. Sensitivity analysis with respect to the calculation of African dust was also performed, in order to identify major parameters affecting the estimated net dust concentrations. African dust contribution to PM concentrations was more pronounced in the eastern Mediterranean, with the mean annual relative contribution to PM10 decreasing from 21 % in Athens, to 5 % in Florence, and around 2 % in Milan, Barcelona and Porto. The respective contribution to PM2. 5 was calculated equal to 14 % in Athens and from 1.3 to 2.4 % in all other cities. High seasonal variability of contributions was observed, with dust transport events occurring at different periods in the western and eastern Mediterranean basin. Sea salt was mostly related to the coarse mode and also exhibited significant seasonal variability. Sea-salt concentrations were highest in Porto, with average relative contributions equal to 12.3 % for PM10. Contributions from uncontrolled forest fires were quantified only for Porto and were low on an annual basis (1.4 and 1.9 % to PM10 and PM2. 5, respectively); nevertheless, contributions were greatly increased during events, reaching 20 and 22 % of 24 h PM10 and PM2. 5 concentrations, respectively.

scholarly journals Aerosol sources and their contribution to the chemical composition of aerosols in the Eastern Mediterranean Sea during summertime

2003 ◽  
Vol 3 (1) ◽  
pp. 291-302 ◽  
Author(s):  
J. Sciare ◽  
H. Bardouki ◽  
C. Moulin ◽  
N. Mihalopoulos
Keyword(s):  
Chemical Composition ◽  
Mediterranean Sea ◽  
Central Europe ◽  
Eastern Mediterranean ◽  
Sea Salt ◽  
Anthropogenic Emissions ◽  
Eastern Mediterranean Sea ◽  
Air Masses ◽  
Wide Range ◽  
Aerosol Sources

Abstract. A detailed study on the temporal variability of compounds important in controlling aerosol chemical composition was performed during a one-month experiment conducted during summer 2000 at a background site on Crete, in the Eastern Mediterranean Sea. Contribution of different aerosol sources in the Eastern Mediterranean Basin could be investigated at this location since the site is influenced by a wide range of air masses originating mainly in Europe and Africa. Chemical apportionment was performed for various air mass origins and showed a strong impact of anthropogenic emissions in the Turkey and Central Europe sectors, with black carbon (BC) and non-sea-salt sulfate (nss-SO4) concentrations higher than observed in the Eastern and Western Europe sectors. High levels of non-sea-salt calcium (nss-Ca) were associated with air masses from Africa but also from Central Turkey. Evidence was found that BC calculation based on light absorbance during dust events was biased. This quality-controlled high temporal resolution dataset allowed to investigate in detail the source-receptor relationships responsible for the levels of BC, nss-SO4 and sulfur dioxide (SO2), observed in Crete. Among the results obtained from this model, the major contribution of Turkey and Central Europe was confirmed in terms of anthropogenic emissions. Comparisons with remote optical properties obtained from Satellite observations (SEAWIFS) north of Crete indicates that our ground based aerosol characterization was suitable for describing aerosol properties in the atmospheric column for most of the time during the campaign.

scholarly journals Fine particle pH and gas–particle phase partitioning of inorganic species in Pasadena, California, during the 2010 CalNex campaign

2017 ◽  
Vol 17 (9) ◽  
pp. 5703-5719 ◽  
Author(s):  
Hongyu Guo ◽  
Jiumeng Liu ◽  
Karl D. Froyd ◽  
James M. Roberts ◽  
Patrick R. Veres ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Fine Particle ◽  
Eastern Mediterranean ◽  
Sea Salt ◽  
Phase Partitioning ◽  
Complex Interactions ◽  
Southeastern Us ◽  
Internal Mixing ◽  
Inorganic Species ◽  
Nitrate Concentrations

Abstract. pH is a fundamental aerosol property that affects ambient particle concentration and composition, linking pH to all aerosol environmental impacts. Here, PM1 and PM2. 5 pH are calculated based on data from measurements during the California Research at the Nexus of Air Quality and Climate Change (CalNex) study from 15 May to 15 June 2010 in Pasadena, CA. Particle pH and water were predicted with the ISORROPIA-II thermodynamic model and validated by comparing predicted to measured gas–particle partitioning of inorganic nitrate, ammonium, and chloride. The study mean ± standard deviation PM1 pH was 1.9 ± 0.5 for the SO42−–NO3−–NH4+–HNO3–NH3 system. For PM2. 5, internal mixing of sea salt components (SO42−–NO3−–NH4+–Na+–Cl−–K+–HNO3–NH3–HCl system) raised the bulk pH to 2.7 ± 0.3 and improved predicted nitric acid partitioning with PM2. 5 components. The results show little effect of sea salt on PM1 pH, but significant effects on PM2. 5 pH. A mean PM1 pH of 1.9 at Pasadena was approximately one unit higher than what we have reported in the southeastern US, despite similar temperature, relative humidity, and sulfate ranges, and is due to higher total nitrate concentrations (nitric acid plus nitrate) relative to sulfate, a situation where particle water is affected by semi-volatile nitrate concentrations. Under these conditions nitric acid partitioning can further promote nitrate formation by increasing aerosol water, which raises pH by dilution, further increasing nitric acid partitioning and resulting in a significant increase in fine particle nitrate and pH. This study provides insights into the complex interactions between particle pH and nitrate in a summertime coastal environment and a contrast to recently reported pH in the eastern US in summer and winter and the eastern Mediterranean. All studies have consistently found highly acidic PM1 with pH generally below 3.

scholarly journals AIRUSE-LIFE +: Estimation of natural source contributions to urban ambient air PM<sub>10</sub> and PM<sub>2.5</sub> concentrations in Southern Europe. Implications to compliance with limit values

2016 ◽  
Author(s):  
Evangelia Diapouli ◽  
Manousos I. Manousakas ◽  
Stergios Vratolis ◽  
Vasiliki Vasilatou ◽  
Stella Pateraki ◽  
...  
Keyword(s):  
Forest Fires ◽  
Seasonal Variability ◽  
Urban Areas ◽  
Eastern Mediterranean ◽  
Ambient Air ◽  
Sea Salt ◽  
Limit Values ◽  
Natural Sources ◽  
African Dust ◽  
Pm10 And Pm2.5

Abstract. Natural sources' contribution to ambient air particulate matter (PM) concentrations is often not considered; however, it may be significant for certain areas and during specific periods of the year. In the framework of the AIRUSE-LIFE+ project, state-of-the-art methods have been employed for assessing the contribution of major natural sources (African dust, sea salt and forest fires) to PM concentrations, in Southern European urban areas. 24 h measurements of PM10 and PM2.5 mass and chemical composition were performed over the course of a year in five cities: Porto, Barcelona, Milan, Florence and Athens. Net African dust and sea salt concentrations were calculated based on the methodologies proposed by EC (SEC 2011/208). The contribution of uncontrolled forest fires was calculated through receptor modelling. Sensitivity analysis with respect to the calculation of African dust was also performed, in order to identify major parameters affecting the estimated net dust concentrations. African dust contribution to PM concentrations was more pronounced in Eastern Mediterranean, with the mean annual relative contribution to PM10 decreasing from 21 % in Athens, to 5 % in Florence, and around 2 % in Milan, Barcelona and Porto. The respective contribution to PM2.5 was calculated equal to 14 % in Athens and from 1.3 to 2.4 % in all other cities. High seasonal variability of contributions was observed, with dust transport events occurring at different periods in the Western and Eastern Mediterranean basin. Sea salt was mostly related to the coarse mode and also exhibited significant seasonal variability. Sea salt concentrations were highest in Porto, with average relative contributions equal to 12.3 % for PM10. Contributions from uncontrolled forest fires were quantified only for Porto and were low on an annual basis (1.4 % and 1.9 % to PM10 and PM2.5, respectively); nevertheless, contributions were greatly increased during events, reaching 20 and 22 % of 24 h PM10 and PM2.5 concentrations, respectively.

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