HR: 0800h
AN: A41D-0745    [Abstracts]
TI: On the Importance of Nitrate as IAE-Agent in West-Europe
AU: * ten Brink, H
EM: tenbrink@ecn.nl
AF: ECN, Energy-research Centre of the Netherlands, Westerduinweg 3, 1755LE, Petten, Netherlands
AU: Otjes, R
EM: otjes@ecn.nl
AF: ECN, Energy-research Centre of the Netherlands, Westerduinweg 3, 1755LE, Petten, Netherlands
AU: Jongejan, P
EM: jongejan@ecn.nl
AF: ECN, Energy-research Centre of the Netherlands, Westerduinweg 3, 1755LE, Petten, Netherlands
AU: Kos, G
EM: g.kos@ecn.nl
AF: ECN, Energy-research Centre of the Netherlands, Westerduinweg 3, 1755LE, Petten, Netherlands
AB: We measured the activation of nitrate-aerosol in our large flow-through cloud chamber. The chamber produces a number of cloud droplets that is representative for that in stratocumulus in our region. The experiments proceed as follows. Aerosol size-spectra are determined both in the air entering the cloud chamber and at the exit of the chamber. From the difference in the spectra, in combination with the number of cloud droplets formed, we deduce which particles served as CCN. On-line chemical analysis shows that in polluted air the amount of nitrate in the CCN is similar to the concentration of sulphate. The chamber is strategically located at the coast of the North-Sea, where arctic air from the North contains a low concentration of CCN; in polluted air coming from other directions the CCN loadings are higher. The difference in the number of cloud droplets that are formed in the two types of air is an empirical measure for the regional IAE.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting