title: Optical and physical properties of stratospheric aerosols from balloon measurements in the visible and near-infrared domains. III. Presence of aerosols in the middle stratosphere.
abstract: The aerosol extinction measurements in the ultraviolet and visible wavelengths by the balloonborne spectrometer Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON) show that aerosols are present in the middle stratosphere, above 25-km altitude. These observations are confirmed by the extinction measurements performed by a solar occultation radiometer. The balloonborne Laboratoire de Météorologie Dynamique (LMD) counter instrument also confirms the presence of aerosol around 30-km altitude, with an unrealistic excess of micronic particles assuming that only liquid sulfate aerosols are present. An unexpected spectral structure around 640-nm observed by SALOMON is also detectable in extinction measurements by the satellite instrument Stratospheric Aerosols and Gas Experiment III. This set of measurements could indicate that solid aerosols were detected at these altitude ranges. The amount of soot detected up to now in the lower stratosphere is too low to explain these measurements. Thus, the presence of interplanetary dust grains and micrometeorites may need to be invoked. Moreover, it seems that these grains fill the stratosphere in stratified layers.
authors: Laboratoire de Physique et Chimie de l'Environnement, Centre National de la Recherche Scientifique, F-45071 Orleans cedex 2, France. jbrenard@cnrs-orleans.fr
authors: Jean-Baptiste
authors: JB
authors: Renard
authors: Joëlle
authors: J
authors: Ovarlez
authors: Gwenaël
authors: G
authors: Berthet
authors: Didier
authors: D
authors: Fussen
authors: Filip
authors: F
authors: Vanhellemont
authors: Colette
authors: C
authors: Brogniez
authors: Edith
authors: E
authors: Hadamcik
authors: Michel
authors: M
authors: Chartier
authors: Henri
authors: H
authors: Ovarlez