Atmosphärische Messungen der Spurengase HNO3 und SO2 und Untersuchungen der Wechselwirkungen mit Mineralstaub-Aerosol

Half of the atmospheric aerosol mass consists of mineral dust. Mineral dust may have a permanent influence on the global climate by means of the impact on the planetary albedo and the interaction with atmospheric trace gases. Within the scope of this work field measurements of the trace gases HNO3 and SO2 and the interactions with mineral dust aerosol were conducted at Iza˜na, Tenerife at a height of 2370m using chemical ionization mass spectrometry. The measurements were part of the EU project MINATROC(MINeral dust And TROpospheric Chemistry ). Extensive background and calibration measurements have been carried out for reliable quantification of mole fractions in the order of a few parts per trillion. As a result it was possible to obtain characteristics of accumulative effects on the intake orifice for the first time. The field measurements showed that during a major dust event the HNO3 concentration started out at 350 pptv and dropped below the detection limit of 16 pptv. After the mineral dust concentration dropped the HNO3 concentration returned to normal. Outside of the dust event typical concentrations for HNO3 were in the range of 100 and 300 pptv. There was no hint on any correlation of SO2 and mineral dust during the observations. Typical concentrations of SO2 were in the range of 20 to 70 pptv, only increasing to 0.5 to 1.5 ppbv when local pollution reached the measuring statio