HR: 0800h
AN: A51C-0071    [Abstracts]
TI: Nitrogen Oxide Measurements in Urban Environments Using a Novel LED-Driven Long-Path DOAS Instrument
AU: * Kern, C
EM: christoph.kern@iup.uni-heidelberg.de
AF: Institut fuer Umweltphysik, Universitaet Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AU: Trick, S
EM: strick@iup.uni-heidelberg.de
AF: University of California Los Angeles, USA Department of Atmospheric and Oceanic Sciences, 405 Hilgard Ave, Box 951565, 7127 Math Sciences Building, Los Angeles, CA 90095-1565 United States
AU: Zingler, J
EM: jzingler@iup.uni-heidelberg.de
AF: Institut fuer Umweltphysik, Universitaet Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AU: Rippel, B
EM: brippel@iup.uni-heidelberg.de
AF: Institut fuer Umweltphysik, Universitaet Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AU: Pedersen, D
EM: pedersen@pob.huji.ac.il
AF: Institute of Earth Sciences, Hebrew University of Jerusalem, Edmond Safra Campus, Givat Ram, Jerusalem, IL-91904 Israel
AU: Platt, U
EM: uplatt@iup.uni-heidelberg.de
AF: Institut fuer Umweltphysik, Universitaet Heidelberg, Im Neuenheimer Feld 229, Heidelberg, 69120 Germany
AB: Nitrogen oxides and especially the nitrate radical play an important role in the chemical processes of the urban boundary layer. The long-path Differential Optical Absorption Spectroscopy (DOAS) measurement technique is a well established method for measuring atmospheric trace gases such as these along a defined light path. Steady advances in light-emitting diode (LED) technology have led to the applicability of LEDs as light sources for active DOAS measurements, where they represent a potentially very advantageous alternative to common thermal emitters for a variety of reasons including low cost, high durability and reduced power consumption. The assets and drawbacks of these modern light sources will be discussed, and the design of a first LED-powered instrument shown. The novel instrumentation was used to conduct nitrogen oxide measurements over the cites of Heidelberg and Jerusalem. In both cases, NO3 mixing ratios upwards of 150 ppt were found on some nights. The results of these experiments will be presented along with their implications for the chemistry of urban source regions.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005