title: Stratospheric sulfuric Acid layer: evidence for an anthropogenic component.
abstract: Recent measurements of small aerosol particles in the stratosphere over Laramie, Wyoming, indicate low-concentration background conditions. A comparison of measurements made some 20 years ago with the present background concentration reveals the possibility of an increase of 9 percent per year. Since the aerosol particles are predominantly sulfuric acid droplets which form in the stratosphere from tropospheric sulfur-containing gases, such an increase may be related to man-made sulfur emissions.
authors.forename: D J
authors.initials: DJ
authors.lastname: Hofmann
authors.forename: J M
authors.initials: JM
authors.lastname: Rosen