scholarly journals Sea-salt aerosol chemistry in coastal areas: A model study

2001 ◽  
Vol 106 (D1) ◽  
pp. 1271-1296 ◽  
Author(s):  
Jana Moldanová ◽  
Evert Ljungström
2006 ◽  
Vol 6 (3) ◽  
pp. 3657-3685 ◽  
Author(s):  
R. von Glasow

Abstract. The reaction of the hydroxyl radical with chloride on the surface of sea salt aerosol producing gas phase Cl2 and particulate OH- and its implications for the chemistry of the marine boundary layer under coastal, remote, and very remote conditions have been investigated with a numerical model. This reaction had been suggested by Laskin et al. (2003) to play a major role in the sulfur cycle in the marine boundary layer by increasing the sulfate production in sea salt by O3 oxidation due to the additional production of alkalinity in the particle. Based on literature data a new &quotbest estimate'' for the rate coefficient of the reaction was deduced and applied, showing that the additional initial sulfate production by this reaction is less than 1%, therefore having only a minor impact on sulfate production. Even though the gas phase concentration of Cl2 increased strongly in the model the concentration of Cl radicals increased by less than 5% for the &quotbest guess'' case. Additional feedbacks between the cycles of chlorine and sulfur in the marine boundary layer are discussed as well as a two-stage acidification of large fresh sea salt aerosol.


2006 ◽  
Vol 6 (11) ◽  
pp. 3571-3581 ◽  
Author(s):  
R. von Glasow

Abstract. The reaction of the hydroxyl radical with chloride on the surface of sea salt aerosol producing gas phase Cl2 and particulate OH− and its implications for the chemistry of the marine boundary layer under coastal, remote, and very remote conditions have been investigated with a numerical model. This reaction had been suggested by Laskin et al. (2003) to play a major role in the sulfur cycle in the marine boundary layer by increasing the sulfate production in sea salt by O3 oxidation due to the additional production of alkalinity in the particle. Based on literature data a new "best estimate" for the rate coefficient of the reaction was deduced and applied, showing that the additional initial sulfate production by this reaction is less than 1%, therefore having only a minor impact on sulfate production. Even though the gas phase concentration of Cl2 increased strongly in the model, the concentration of Cl radicals increased by less than 5% for the "best guess" case. Additional feedbacks between the cycles of chlorine and sulfur in the marine boundary layer are discussed as well as a two-stage acidification of large fresh sea salt aerosol.


2015 ◽  
Vol 101 ◽  
pp. 41-48 ◽  
Author(s):  
M. Spada ◽  
O. Jorba ◽  
C. Pérez García-Pando ◽  
Z. Janjic ◽  
J.M. Baldasano
Keyword(s):  
Sea Salt ◽  

1998 ◽  
Vol 26 ◽  
pp. 156-160 ◽  
Author(s):  
Richard Hodgkins ◽  
Martyn Tranter

The chemical composition of snow and meltwater in the 13 km2 catchment of Scott Turnerbreen, Svalbard, was investigated during the spring and summer of 1993. This paper assesses the provenance of solute in the snowpack and its impact on runoff chemistry. Dry snow contains 420μeql-1 of solute, is slightly acidic (pH 5.4) and is dominated by Na+ and Cl-. Wet snow is more dilute (total concentration 340μeql-1), and less acidic (pH 5.9). This is consistent with the elution of ions from the snowpack by meltwater. Snowpack solute can be partitioned into the following fractions: sea-salt aerosol, acid aerosol and crustal. About 98% of snowpack solute is sea salt, yielding 22000 kg km-2a-1. The behaviour of snowpack-derived Cl- in runoff is distinctive, peaking at over 800 μeql-1 early in the melt season as runoff picks up, before declining quasi-exponentially. This represents the discharge of snowmelt concentrated by elution within the snowpack which subsequently becomes relatively dilute. A solute yield of 140 kg km-2 a-1 can be attributed to anthropogenically generated acid aerosols, representing long-range atmospheric transport of pollutants, a potential contributor to Arctic runoff acidification.


2018 ◽  
Vol 18 (7) ◽  
pp. 4911-4934 ◽  
Author(s):  
Jonathan Guth ◽  
Virginie Marécal ◽  
Béatrice Josse ◽  
Joaquim Arteta ◽  
Paul Hamer

Abstract. In the frame of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx), we analyse the budget of primary aerosols and secondary inorganic aerosols over the Mediterranean Basin during the years 2012 and 2013. To do this, we use two year-long numerical simulations with the chemistry-transport model MOCAGE validated against satellite- and ground-based measurements. The budget is presented on an annual and a monthly basis on a domain covering 29 to 47° N latitude and 10° W to 38° E longitude. The years 2012 and 2013 show similar seasonal variations. The desert dust is the main contributor to the annual aerosol burden in the Mediterranean region with a peak in spring, and sea salt being the second most important contributor. The secondary inorganic aerosols, taken as a whole, contribute a similar level to sea salt. The results show that all of the considered aerosol types, except for sea salt aerosols, experience net export out of our Mediterranean Basin model domain, and thus this area should be considered as a source region for aerosols globally. Our study showed that 11 % of the desert dust, 22.8 to 39.5 % of the carbonaceous aerosols, 35 % of the sulfate and 9 % of the ammonium emitted or produced into the study domain are exported. The main sources of variability for aerosols between 2012 and 2013 are weather-related variations, acting on emissions processes, and the episodic import of aerosols from North American fires. In order to assess the importance of the anthropogenic emissions of the marine and the coastal areas which are central for the economy of the Mediterranean Basin, we made a sensitivity test simulation. This simulation is similar to the reference simulation but with the removal of the international shipping emissions and the anthropogenic emissions over a 50 km wide band inland along the coast. We showed that around 30 % of the emissions of carbonaceous aerosols and 35 to 60 % of the exported carbonaceous aerosols originates from the marine and coastal areas. The formation of 23, 27 and 27 %, respectively of, ammonium, nitrate and sulfate aerosols is due to the emissions within the marine and coastal area.


1992 ◽  
Vol 02 (04) ◽  
pp. 593-601 ◽  
Author(s):  
Sha Yin ◽  
Liu Pingsheng ◽  
Hu Zhaohui ◽  
Zhong Ming ◽  
Yang Shaojin ◽  
...  

Proton Induced X-ray Emission (PIXE) and Instrumental Neutron Activation Analysis (INAA) techniques were used to measure the contents of 45 elements in 150 air-filter samples collected by cascade impactor with 8 stages at 10 sites in Beijing-Tianjin area of China during the periods of the winter of 1983 and the summer of 1984. It was noticed that the toxic elements such as As, Sb, Se, Pb, Hg, Cu and Ni were mainly enriched in fine particles with diameter less than 2 um. The major seven sources of coal burning, soil dust, oi1 burning, sea-salt aerosol, motor vehicle emission, limestone dust and industrial refuse attributing to the pollution in Tianjin area were identified by Chemical Elements Balance method (CEB). Among them the most important sources were the soil dust and the emission from coal-combustion followed by contributions from limestone and industrial refuse.


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