A Validity Analysis for Refractory Black Carbon Observations Data Using Cosine Similarity Method During the 2021 Yellow Sea-Air Quality Campaign

Black Carbon (BC) is an important substance that affects global warming and it is highly observed in the Asian continent. Aerosols including BC pass through the Yellow Sea and they cause adverse effects on South Korea. However it is not easy to understand the aerosol characteristics and movement over the Yellow Sea due to the sparse observation. The NIMS/KMA (National Institute of Meteorological Sciences/Korea Meteorological Administration) introduced a YES-AQ (Yellow Sea-Air Quality) campaign every spring since 2018, and tried to observe BC from the atmospheric research aircraft, NARA (NIMS Atmospheric Research Aircraft). The NARA observes number concentrations and mass concentrations of BC single particles using SP2 (Single Particle Soot Photometer), and the light absorption coefficient of BC using TAP (Tricolor Absorption Photometer) with three wavelengths. In order to analyze the validity of the 550 nm light absorption coefficient observed from TAP, the similarity was confirmed by comparing the measurements of the 550 nm light scattering coefficient from Nephelo-meter during the 2021 YES-AQ campaign. In addition, as a result of verifying the light absorption coefficient measurement in TAP and the rBC (refractory BC) mass concentrations measurement in SP2 using the Cosine Similarity method, it was confirmed that the tendency showed good agreement with cosine similarity of 0.953 +/- 0.033.