Figure 6:

Time series of the hourly average PM_2.5 concentrations during the KORUS-AQ period for AirKorea sites in Seoul City. Median CO/CO₂ slopes are shown for DC-8 flight days and are taken from descent profiles over Seoul. Statistics for the CO/CO₂ slopes (median and interquartile range) are shown for 1-minute data periods with slopes having a significant correlation (R² > 0.5). Symbol size is proportional to the fraction of data having significant CO/CO₂ correlation. Statistics are shown for both the boundary layer (BL, orange) and lower free troposphere (LFT, green). As in Figure 2, meteorological periods are annotated at the top of the figure. DOI: https://doi.org/10.1525/elementa.424.f6