TY  - JOUR
A1  - Bonn, Boris
A1  - Sun, Shang
A1  - Haunold, Werner
A1  - Sitals, Robert
A1  - Beesel, Eric van
A1  - Santos, Luis dos
A1  - Nillius, Björn
A1  - Jacobi, Stefan
T1  - COMPASS : comparative particle formation in the atmosphere using portable simulation chamber study techniques
T2  - Atmospheric measurement techniques
N2  - In this study we report the set-up of a novel twin chamber technique that uses the comparative method and establishes an appropriate connection of atmospheric and laboratory methods to broaden the tools for investigations. It is designed to study the impact of certain parameters and gases on ambient processes, such as particle formation online, and can be applied in a large variety of conditions. The characterisation of both chambers proved that both chambers operate identically, with a residence time xT (COMPASS1) = 26.5 ± 0.3 min and xT (COMPASS2) = 26.6 ± 0.4 min, at a typical flow rate of 15 L min−1 and a gas leak rate of (1.6 ± 0.8) × 10−5 s−1. Particle loss rates were found to be larger (due to the particles' stickiness to the chamber walls), with an extrapolated maximum of 1.8 × 10−3 s−1 at 1 nm, i.e. a hundredfold of the gas leak rate. This latter value is associated with sticky non-volatile gaseous compounds, too. Comparison measurement showed no significant differences. Therefore operation under atmospheric conditions is trustworthy. To indicate the applicability and the benefit of the system, a set of experiments was conducted under different conditions, i.e. urban and remote, enhanced ozone and terpenes as well as reduced sunlight. In order to do so, an ozone lamp was applied to enhance ozone in one of two chambers; the measurement chamber was protected from radiation by a first-aid cover and volatile organic compounds (VOCs) were added using a small additional flow and a temperature-controlled oven. During the elevated ozone period, ambient particle number and volume increased substantially at urban and remote conditions, but by a different intensity. Protection of solar radiation displayed a clear negative effect on particle number, while terpene addition did cause a distinct daily pattern. E.g. adding β pinene particle number concentration rose by 13% maximum at noontime, while no significant effect was observable during darkness. Therefore, the system is a useful tool for investigating local precursors and the details of ambient particle formation at surface locations as well as potential future feedback processes.
Y1  - 2013
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/32971
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-329714
SN  - 1867-8548
SN  - 1867-1381
VL  - 6
SP  - 3407
EP  - 3423
PB  - Copernicus
CY  - Katlenburg-Lindau.
ER  -