Geophysical Research Letters · 1997 · 14 citations · 8 references
Natural SciencesEarth SciencesAtmospheric ChemistryAtmospheric ScienceSpectroscopyAerosol PhysicsAerosol ScienceAir QualityAtmospheric CompositionAtmospheric Trace GasesParticulate MatterAerosol CharacterizationAerosol Number ConcentrationAerosol Optical PropertiesAerosol PropertiesBoundary Layer MeasurementsDifferential Absorption SpectroscopyExtinction Coefficient MeasurementsExtinction Coefficients
Boundary layer trace gas and particulate extinction measurements in the wavelength region from 320 nm to 680 nm have been performed by means of a differential optical absorption spectroscopy (DOAS) system at Cape Arkona (Island Rügen/Germany). The wavelength‐dependent extinction coefficient σ e (λ) is determined from the attenuation of radiation along two paths of different lengths. Nearly simultaneous recording of the concentrations of O 3 and NO 2 within the same air mass allows a correction of their contribution to σ e (λ). The extinction coefficients are compared with volume scattering coefficients measured by an open integrating nephelometer. Differences between the measurements can be attributed to atmospheric inhomogeneities. A simplified model involving monomodal log‐normal distributions is applied to approximate the total particle surface area concentration and an upper limit of the accumulation mode radius. This allows a rough estimate of the particle number concentration. During the summer of 1995 the mean (median) surface area concentration was about 350 (250) µm²/cm³, and the particle number concentration ranged from about 100 cm −3 to some 1000 cm −3 .
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