HR: 0800h
AN: A41A-0016    [Abstracts]
TI: Optical, physical and chemical properties of aerosols at an elevated site (Kleiner Feldberg) in central Europe during the FACE-2004 campaign
AU: * Chand, D
EM: duli@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AU: Schmid, O
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AU: Juergens, N
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AU: Curtius, J
AF: Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, D-55099 Germany
AU: Frank, G
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AU: Drewnick, F
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AU: Schneider, J
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AU: Walter, S
AF: Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, D-55099 Germany
AU: Kurten, A
AF: Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, D-55099 Germany
AU: Nillius, B
AF: Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, D-55099 Germany
AU: Borrmann, S
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AU: Borrmann, S
AF: Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, D-55099 Germany
AU: Andreae, M O
AF: Max Planck Institute for Chemistry, University Campus, Mainz, D-55020 Germany
AB: As part of the Feldberg Aerosol Characterization Experiment (FACE-2004) optical, physical and chemical measurements of fine aerosols ($<$1.0 $\micron$) were performed at a mountaintop in central Europe. A 1-month long observational campaign was conducted at Kleiner Feldberg in Germany (8.4413 E, 50.2249 N, 810 m asl) from 17 July to 18 August in summer of 2004 with the intensive phase lasting from 19 July to 4 August. Measurements of light scattering by aerosols at dry (at 545 nm), ambient (450, 550 and 700 nm) and humid (545 nm) conditions were conducted during the campaign. In addition, the light absorption coefficient (532 nm) was measured at ambient conditions. The chemical analysis of the aerosols is made using the aerosols mass spectrometer. The extensive aerosols optical parameters (scattering and absorption coefficients) are used to calculate the intensive optical parameters (single scattering albedo and Angstrom exponent). Measurements of aerosol mass concentration (PM 1.0), size distribution, number concentrations and chemical composition are used to retrieve mass scattering and absorption efficiencies as well as to facilitate interpretation of the optical measurements. In addition, observations of carbon monoxide (CO), carbon dioxide (CO$_2$) and meteorological parameters are being investigated to trace the nature and source of the air parcels. These observations suggest that this site shows a signature of mixed weather condition in July-August. In addition to the locally-polluted and regional-background air masses types, there were some events of clean periods when the aerosol mass and scattering coefficient went down to very low levels. The observed size distributions indicate that the most of the particles were below 400 nm in diameter with a number peak at about 80 nm. The observed range (with the averages in parenthesis) of ambient scattering coefficient (550 nm), mass concentration, CO and CN during the campaign were 1-150 (32) Mm$^-$$^1$, 1-80 (16) 10$^-$$^6$g m$^-$$^3$, 120-350 (200) ppb and 1050-40000 (4437) cm$^-$$^3$ respectively. The average mass scattering efficiency at 550 nm is about 2 m$^2$ g$^-$$^1$. Large hygroscopic growth in scattering coefficient is consistent with the presence of significant amount of water soluble inorganic (sulphate, nitrate, ammonium) mass. The optical, physical and chemical properties of aerosols for different meteorological conditions will be presented.
DE: 4801 Aerosols (0305)
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting