Gypsum and Other Calcium-Rich Aerosol Particles above the North Sea

Abstract

Ca-containing particles, especially CaSO 4 particles, have been encountered in several atmospheric aerosol studies. An overview is given of the different sources of airborne Ca-containing particles. The North Sea atmosphere is studied to identify the different Ca-containing particle types and to find the correlation between their occurrence and the source regions of the corresponding air masses. About 50 000 individual aerosol samples were collected above the Southern Bight of the North Sea for several wind directions and analyzed for their composition using electron probe X-ray microanalysis. Nonhierarchical cluster analysis is performed on the data to reveal the different particle types, their relative abundances and their sources. CaSO 4 in most cases constitutes the largest fraction of the Ca-containing particles. Extremely high numbers of CaSO 4 particles are found for northeastern winds, coming from the central part of Germany, suggesting that a great fraction is derived from anthropogenic sources located in this region. Among the other Ca-containing particle types are the aluminosilicates, CaCO 3 , Fe-Ca-rich particles, and CaSO 4 or CaCO 3 in combination with NaCl.

Individual Particle Analysis of Atmospheric Aerosols at Nam Co, Tibetan Plateau

“…The Note: * means the background signal from Au/Pd coating. 0.5-1 1-2.5 2.5-10 0.5-1 1-2.5 2.5-10 0.5-1 1-2.5 2.5-10 0.5-1 1-2.5 2. primary source is crustal material because gypsum is a typical mineral in the earth crust (Hoornaert et al, 1996). The other source is conversion of calcite to gypsum by chemical reactions with sulfuric acid or ammonium sulfate during transport (Liu et al, 2005).…”

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

“…These regions belong to the strongest source areas of aerosols and Ca in Northern Europe (Häsänen et al, 1997;Lee and Pacyna, 1999;Jalkanen et al, 2000;EMEP, 2002), and thus, the pollution episode Ca-rich particles might originate mainly from these areas. A more detailed source identification of Ca-rich particles is difficult because they can originate from various sources, including fossil fuel and biomass burning, cement and metal industries, soil dust and marine sources (Hoornaert et al, 1996;Lee and Pacyna, 1999;Li et al, 2003b). However, the relative amount of Mg and Si in Ca-rich particles was highest in sample 6 and lowest in samples 10-22 (see Fig.…”

The Effect of Traction Sanding on Urban Suspended Particles in Finland

“…Katrinak et al (1995) have estimated the relative errors of the ZAF-procedure for the atomic fractions observed in the individual particles to be 10-20%. Because of the inaccuracies of the quantitative analysis method (ZAF) the weight percentages were used more in a semi-quantitative way: the elements with a weight percentage of over 1% were considered present (see Hoornaert et al, 1996).…”

“…This class included sea salt particles, as well as Na 2 SO 4 -particles, which might be originally sea salt, in which Cl has been substituted by SO 4 in the atmosphere (Kerminen et al, 1997;Song & Carmichael, 1998). Ca-S-O-particles were most likely CaSO 4 , which can be of combustion origin or formed in the atmosphere from CaCO 3 (Hoornaert et al, 1996;Mori et al, 1998;Song and Carmichael, 1999). CaCO 3 -particles could originate from concrete materials (De Miguel et al, 1997) or from the filler material of asphalt (Hoornaert et al, 1996).…”

“…Ca-S-O-particles were most likely CaSO 4 , which can be of combustion origin or formed in the atmosphere from CaCO 3 (Hoornaert et al, 1996;Mori et al, 1998;Song and Carmichael, 1999). CaCO 3 -particles could originate from concrete materials (De Miguel et al, 1997) or from the filler material of asphalt (Hoornaert et al, 1996). Particles with high iron content most probably originate from wearing and corrosion of the metal surfaces and brakes (Garg et al, 2000).…”