GAW Report No. 205 - IGAC Project

CHAPTER 7 – OVERVIEW OF INTERNATIONAL COLLABORATIVE RESEARCH ACTIVITIESTable 1 - Summary of findings by IMPACTTopic Major findings ReferencesInstrumentation A HNO3-CIMS with a new calibration/zero systemwas developed.Performance of an Aerodyne AMS was evaluatedbased on intercomparison with a PILS-IC andSunset OC.A new method to quantify BC coating wasdeveloped using an SP2.OH/HO2/O3Measured OH was reproduced by a box model inwinter and summer.Measured HO2 was underestimated by the model inthe high-NOX regime.VOCs Seasonal variation of C2-C7 non-methanehydrocarbons was quantified.BCDiesel emissions were identified as a major sourceof BC in Tokyo.NitrateNitrate-HNO3 partitioning in summer was influencedby vertical mixing.SulphateOnly a small fraction (3% in winter and 18% insummer) of SO2 emitted was converted to sulphate.Organic aerosol Seasonal and diurnal variation of POA and SOAwas quantified.Most SOA (OOA) was found to be water soluble.Hygroscopicity and CCNOutflow from TokyoHygroscopicity and CCN activity were perturbed byorganics.BC can act as CCN with a small amount of coatingmaterial.Significant formation of organics and alteration ofBC mixing state took place within ~0.5 days insummer[Kita et al., 2006; Takegawa etal., 2005; Moteki and Kondo,2007; 2008][Kanaya et al., 2007; 2008][Shirai et al., 2007][Kondo et al., 2006;Shiraiwa et al., 2007][Morino et al., 2006][Miyakawa et al., 2007][Takegawa et al., 2006a;2006b; Miyazaki et al., 2006;Kondo et al., 2007; 2008;Matsui et al., 2009][Mochida et al., 2006; 2008Kuwata et al., 2009; Kuwataand Kondo, 2009][Takegawa et al., 2006b;Shiraiwa et al., 2007; Miyakawaet al., 2008]Figure 13 - System for megacity air quality studies: Observations at 1-2 main stations (st.) and routine monitoring stations,modelling, and science-policy feedback269