Japan Geoscience Union Meeting 2014

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Symbol A (Atmospheric, Ocean, and Environmental Sciences) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS22_30PM2] Atmospheric Chemistry

Wed. Apr 30, 2014 4:15 PM - 6:00 PM 511 (5F)

Convener:*Nobuyuki Takegawa(Research Center for Advanced Science and Technology, University of Tokyo), Yousuke Sawa(Geochemical Research Department, Meteorological Research Institute), Yugo Kanaya(Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology), Kenshi Takahashi(Research Institute for Sustainable Humanosphere, Kyoto University), Hiroshi Tanimoto(National Institute for Environmental Studies), Chair:Hitoshi MATSUI(Japan Agency for Marine-Earth Science and Technology)

5:15 PM - 5:30 PM

[AAS22-05] Temporal variations of aerosol, glyoxal, and formaldehyde retrieved by MAX-DOAS based on detailed error analysis

*Hitoshi IRIE1, Sei CHIN1, Wentao NI1, Tomoki NAKAYAMA2, Akihiro YAMAZAKI3, Takamura TAMIO1, Pradeep KHATRI1 (1.Chiba University, 2.Nagoya University, 3.Meteorological Research Institute)

Keywords:CHOCHO, HCHO, MAX-DOAS, CRDS, sky radiometer

The degradation of volatile organic compounds (VOCs) results in the formation of ozone (O3) and secondary organic aerosols (SOA) in the troposphere. This process consists of the oxidation of VOCs by hydroxyl radical (OH), O3, and nitrate radical (NO3). Detailed understanding of the VOC degradation mechanism is challenged by the co-existence of vast variety of VOC species in the atmosphere. However, investigations on ubiquitous oxidation intermediates, e.g., formaldehyde (HCHO) and glyoxal (CHOCHO), can help us to test and improve the current knowledge of the VOC sources and degradation pathways.We installed one ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) system in Meteorological Research Institute (MRI) located at Tsukuba, Japan (36.06N, 130.13E) in June 2010. In addition, two more systems were installed in Chiba University at Chiba, Japan (35.63N, 140.10E) in June and December 2012, respectively. Since then, we have retrieved lower-tropospheric vertical profile information for eight components; aerosol extinction coefficients at two wavelengths, 357 and 476 nm, and NO2, HCHO, CHOCHO, H2O, SO2, and O3 concentrations. For a detailed evaluation for the aerosol retrieval, which is a key step in the MAX-DOAS eight-component retrieval, simultaneous aerosol observations with the Cavity Ring-Down Spectroscopy (CRDS) and the sky radiometer were conducted at Tsukuba on October 5-18, 2010 and September 7-18, 2012. At Chiba, in addition to the comparison with sky radiometer data, a self-consistency test was performed by comparing results obtained from two MAX-DOAS systems operated at the same place. Through these detailed evaluations, our retrieval method was improved significantly, attaining excellent agreement with CRDS and sky radiometer data. On the basis of these efforts, seasonal and diurnal temporal variations in HCHO and CHOCHO concentrations retrieved from our MAX-DOAS system are discussed in this talk.