Rural continental aerosol properties and processes observed during the Hohenpeissenberg Aerosol Characterization Experiment (HAZE2002) N. Hock1, J. Schneider1, S. Borrmann1,2, A. Römpp3,*, G. Moortgat3, T. Franze4, C. Schauer4, U. Pöschl4,**, C. Plass-Dülmer5, and H. Berresheim5,*** 1Particle Chemistry Dept., Max Planck Institute for Chemistry, Mainz, Germany 2Institute for Atmospheric Physics, Johannes Gutenberg University, Mainz, Germany 3Atmospheric Chemistry Dept., Max Planck Institute for Chemistry, Mainz, Germany 4Institute of Hydrochemistry, Technical University of Munich, Germany 5German National Meteorological Service (DWD), Observatory Hohenpeissenberg, Germany *now at: Institute for Inorganic and Analytical Chemistry, Justus Liebig University Giessen, Germany **now at: Biogeochemistry Dept., Max Planck Institute for Chemistry, Mainz, Germany ***now at: Dept. of Physics, National University of Ireland, Galway, Ireland
Abstract. Detailed investigations of the chemical and microphysical properties of
rural continental aerosols were performed during the HAZE2002 experiment,
which was conducted in May 2002 at the Meteorological Observatory
Hohenpeissenberg (DWD) in Southern Germany.
Online measurements included: Size-resolved chemical
composition of submicron particles; total
particle number concentrations and size distributions over the diameter
range of 3 nm to 9 μm; gas-phase concentration of monoterpenes, CO,
O3, OH, and H2SO4. Filter sampling and offline analytical techniques were used to
determine: Fine particle mass (PM2.5), organic, elemental and total carbon
in PM2.5 (OC2.5, EC2.5, TC2.5), and selected organic compounds (dicarboxylic
acids, polycyclic aromatic hydrocarbons, proteins).
Overall, the non-refractory components of submicron particles detected by
aerosol mass spectrometry (PM1, 6.6±5.4 μg m−3, arithmetic
mean and standard deviation) accounted for ~62% of PM2.5 determined
by filter gravimetry (10.6±4.7 μg m−3). The relative
proportions of non-refractory submicron particle components were:
(23±39)% ammonium nitrate, (27±23)% ammonium sulfate, and (50±40)% organics (OM1).
OM1 was closely correlated with PM1 (r2=0.9) indicating a
near-constant ratio of non-refractory organics and inorganics.
The average ratio of OM1 to OC2.5 was 2.1±1.4, indicating a high proportion of
heteroelements in the organic fraction of the sampled rural aerosol. This is
consistent with the high ratio of oxygenated organic aerosol (OOA) over
hydrocarbon-like organic aerosol (HOA) inferred from the AMS results (4:1),
and also with the high abundance of proteins (~3%) indicating a
high proportion of primary biological material (~30%) in PM2.5.
This finding was confirmed by low abundance of PAHs (<1 ng m−3) and EC (<1 μg m−3)
in PM2.5 and detection of several secondary organic aerosol compounds (dicarboxylic
acids) and their precursors (monoterpenes).
New particle formation was observed almost every day with particle number
concentrations exceeding 104 cm−3 (nighttime background level
1000–2000 cm−3). Closer inspection of two major events indicated that
the observed nucleation agrees with ternary H2SO4/H2O/NH3 nucleation and that condensation of both organic and inorganic species
contributed to particle growth.
Citation: Hock, N., Schneider, J., Borrmann, S., Römpp, A., Moortgat, G., Franze, T., Schauer, C., Pöschl, U., Plass-Dülmer, C., and Berresheim, H.: Rural continental aerosol properties and processes observed during the Hohenpeissenberg Aerosol Characterization Experiment (HAZE2002), Atmos. Chem. Phys., 8, 603-623, doi:10.5194/acp-8-603-2008, 2008.