Aerosol chemical composition at Cabauw, The Netherlands as observed in two intensive periods in May 2008 and March 2009 A. A. Mensah1,*, R. Holzinger2, R. Otjes3, A. Trimborn1, Th. F. Mentel1, H. ten Brink3, B. Henzing4, and A. Kiendler-Scharr1 1Institut für Energie- und Klimaforschung: Troposphäre (IEK 8), Forschungszentrum Jülich GmbH, Jülich, Germany 2Institute for Marine and Atmospheric research Utrecht (IMAU), Utrecht, The Netherlands 3Energy research Centre of The Netherlands (ECN), Petten, The Netherlands 4Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands *now at: Institute of Atmospheric and Climate Science (IAC), ETH Zurich, Zurich, Switzerland
Abstract. Observations of aerosol chemical composition in Cabauw, the Netherlands, are
presented for two intensive measurement periods in May 2008 and March 2009.
Sub-micron aerosol chemical composition was measured by an Aerodyne Aerosol
Mass Spectrometer (AMS) and is compared to observations from aerosol size
distribution measurements as well as composition measurements with a Monitor
for AeRosol and GAses (MARGA) based instrument and a Thermal-Desorption
Proton-Transfer-Reaction Mass-Spectrometer (TD-PTR-MS). An overview of the
data is presented and the data quality is discussed. In May 2008 enhanced
pollution was observed with organics contributing 40% to the PM1
mass. In contrast the observed average mass loading was lower in March 2009
and a dominance of ammonium nitrate (42%) was observed. The
semi-volatile nature of ammonium nitrate is evident in the diurnal cycles
with maximum concentrations observed in the morning hours in May 2008 and
little diurnal variation observed in March 2009. Size dependent composition
data from AMS measurements are presented and show a dominance of organics in
the size range below 200 nm. A higher O:C ratio of the organics is observed
for May 2008 than for March 2009. Together with the time series of individual
tracer ions this shows the dominance of OOA over HOA in May 2008.
Citation: Mensah, A. A., Holzinger, R., Otjes, R., Trimborn, A., Mentel, Th. F., ten Brink, H., Henzing, B., and Kiendler-Scharr, A.: Aerosol chemical composition at Cabauw, The Netherlands as observed in two intensive periods in May 2008 and March 2009, Atmos. Chem. Phys., 12, 4723-4742, doi:10.5194/acp-12-4723-2012, 2012.