M. Volken et T. Schumann, A CRITICAL-REVIEW OF BELOW-CLOUD AEROSOL SCAVENGING RESULTS ON MT RIGI, Water, air and soil pollution, 68(1-2), 1993, pp. 15-28
One of the main goals of the 7-year winter precipitation field study o
n ML Rigi (central Switzerland) was a better understanding of the mech
anisms leading to the wet removal of aerosol particles from the atmosp
here. A critical review of the main below-cloud scavenging results of
this event-oriented multidisciplinary project is given. The Mt. Rigi r
esults are compared with a theoretical model applied to experimentally
determined initial and boundary conditions and with literature report
s on similar field studies. For submicron particles significant discre
pancies have been found between experiment and theory, our measurement
s showing scavenging coefficients 20 to 40 times higher on average tha
n model predictions. An attempt is made to explain the differences res
ulting from these two different approaches. There is some evidence tha
t this may arise partly as a result of humidity effects, but other inf
luences are discussed as well.