日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS04] 大気化学

2019年5月30日(木) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:中山 智喜(長崎大学 大学院水産・環境科学総合研究科)、岩本 洋子(広島大学 生物圏科学研究科)、豊田 栄(東京工業大学物質理工学院)、江口 菜穂(Kyushu University)

[AAS04-P07] Simultaneous observations by sky radiometer and MAX-DOAS for characterization of biomass burning plumes in central Thailand in January-April 2016

*入江 仁士1Syedul Hoque1Alessandro Damiani1Al Fatmi1Pradeep Khatri2高村 民雄1Thanawat Jarupongsakul3 (1.千葉大学、2.東北大学、3.チュラロンコン大学)

キーワード:バイオマスバーニング、ホルムアルデヒド、グリオキサール、エアロゾル、スカイラジオメータ、MAX-DOAS

The first intensive multi-component ground-based remote sensing observations by sky radiometer and Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) were performed simultaneously at the SKYNET/Phimai site located in central Thailand (15.18°N, 102.56°E) from January to April 2016. The period corresponds to the dry season associated with the intense biomass burning (BB) activity around the site. The near-surface concentration of formaldehyde (HCHO) retrieved from MAX-DOAS was found to be a useful tracer for absorption aerosols from BB plumes, when BB was the dominant sources of HCHO and absorption aerosols over other sources. As the HCHO concentration tripled from 3 to 9 ppbv, the ratio of gaseous glyoxal to HCHO concentrations in daytime decreased from ~0.04 to ~0.03, responding presumably to the increased contribution of volatile organic compound emissions from BB. In addition, clear increases in aerosol absorption optical depths (AAODs) retrieved from sky radiometer observations were seen with the HCHO enhancement. At a HCHO of 9 ppbv, AAOD at a wavelength of 340 nm reached as high as ~0.15±0.03. The wavelength dependence of AAODs at 340-870 nm was quantified by the absorption Ångström exponent (AAE), providing evidence for the presence of brown carbon aerosols at an AAE of 1.5±0.2. Thus, our multi-component observations around central Thailand are expected to provide unique constraints for understanding physical/chemical/optical properties of BB plumes.