HR: 14:10h
AN: A23D-03    [Abstracts]
TI: Diurnal and Seasonal Variations of Elemental Carbon in Tokyo, Japan
AU: * Kondo, Y
EM: kondo@atmos.rcast.u-tokyo.ac.jp
AF: Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Tok 153-8904 Japan
AU: Komazaki, Y
EM: komazaki@atmos.rcast.u-tokyo.ac.jp
AF: Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Tok 153-8904 Japan
AU: Moteki, N
EM: moteki@atmos.rcast.u-tokyo.ac.jp
AF: Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Tok 153-8904 Japan
AU: Nogami, M
EM: nogami@atmos.rcast.u-tokyo.ac.jp
AF: Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Tok 153-8904 Japan
AU: Takegawa, N
EM: takegawa@atmos.rcast.u-tokyo.ac.jp
AF: Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Tok 153-8904 Japan
AU: Fukuda, M
EM: fukuda@atmos.rcast.u-tokyo.ac.jp
AF: Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Tok 153-8904 Japan
AU: Miyakawa, T
EM: miyakawa@atmos.rcast.u-tokyo.ac.jp
AF: Research Center for Advanced Science and Technology (RCAST), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Tok 153-8904 Japan
AB: Concentrations and mixing state of elemental carbon (EC) were measured, together with carbon monoxide (CO) at RCAST in Tokyo in different seasons in 2003-2004. Measurements of EC were made by using semi-continuous thermal-optical, optical-absorption, and laser induced incandescence (LII) techniques. Measured EC concentrations by these techniques showed very tight correlations, confirming reliability of the EC measurements. The average EC and CO concentrations were about 2.5 ug/m3 and 400 ppbv, respectively. They showed tight correlations throughout the measurement periods. The slope of the EC-CO correlation was highest in the early morning, when the ratio contribution of vehicles with diesel engines to the whole vehicular traffic in Tokyo was highest, suggesting that exhaust from diesel engines is an important source of EC in Tokyo. The EC-CO slope also showed seasonal variation, lowest in winter when the mean temperature was about 0-10C. Changes in mixing state of EC derived from LII are also presented. Despite regulation of emissions of EC from diesel engines started in October 2003, diurnally averaged EC-CO slope did not show significant decease. Possible causes will be discussed.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting