Fig. 1.

Changes of (A) tarball (TB) number fractions, (B) nonsulfate N/K within nontarball particles, and (C) nonsulfate O/K within nontarball particles as photochemical ages increase for each flight. Error bars indicate the 95% confidence intervals. Numbers of measured nontarball particles for the EDS analyses are 2,451, 3,271, 1,962, and 2,085 for flights 1, 2, 3, and 4, respectively. Averaged values of nonsulfate N/K of tarballs are 6.7 ± 0.1, 2.9 ± 0.3, 2.2 ± 0.2, and 0.9 ± 0.2 and those of O/K are 47.6 ± 0.1, 14.1 ± 0.3, 9.9 ± 0.2, and 10.4 ± 0.3 for flights 1, 2, 3, and 4, respectively. All ratios are calculated from weight percentage values.