Open AccessSingle‐particle characterization of four aerosol samples collected in ChunCheon, Korea, during Asian dust storm events in 2002
Author(s) -
Hwang HeeJin,
Ro ChulUn
Publication year - 2005
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005jd006050
Subject(s) - sea salt , single particle analysis , particle (ecology) , aerosol , electron microprobe , asian dust , sulfate , chemical composition , range (aeronautics) , dust storm , microanalysis , mineralogy , nitrate , environmental chemistry , analytical chemistry (journal) , chemistry , materials science , geology , oceanography , metallurgy , organic chemistry , composite material
A single‐particle analytical technique, named low‐ Z particle electron probe X‐ray microanalysis (low‐ Z particle EPMA), employing an ultrathin window X‐ray detector and enabling the quantitative determination of even low‐ Z elements such as C, N, and O, was applied to characterize “Asian dust” samples, collected in ChunCheon, Korea, during four Asian dust storm events on 21 March, 9 April, 17 April, and 11 November in 2002. In this study, it is demonstrated that single‐particle analysis using the low‐ Z particle EPMA provides detailed information on various types of chemical species in the samples. The most abundantly encountered particles, both in coarse and fine fractions, are soil‐derived particles such as aluminosilicates and silicon dioxide, except for the sample collected on 11 November 2002, where reacted CaCO 3 particles are the most abundantly encountered. All four samples are found to have experienced chemical modifications during long‐range transport because the samples contain a significant number of particles composed of chemical species, such as nitrate and sulfate, which resulted from atmospheric reactions of CaCO 3 and sea‐salt particles. This finding implies that CaCO 3 and sea‐salt particles reacted with sulfur and nitrogen oxide species during long‐range transport. The sample collected on 11 November 2002 experienced the most extensive chemical modification during its transport. For this sample, the overall relative abundances of reacted CaCO 3 and reacted sea‐salt particles are 29.9% and 23.2%, respectively. In addition to the observation of the reacted CaCO 3 and sea‐salt particles, reacted K‐containing particles are also encountered in this sample. In this work, it is observed that chemical modification of sea‐salt particles was more extensive than that of CaCO 3 particles. By considering the relative abundances of nitrate‐ and sulfate‐containing particles, nitrate formation from CaCO 3 and sea‐salt particles in the air is found to be more favorable than sulfate formation.