Background stratospheric aerosol layer

Journal Article · Thu Jan 01 04:00:00 EST 1981 · J. Atmos. Sci.; (United States)

DOI:https://doi.org/10.1175/1520-0469(1981)038<0168:OTBSAL>2.0.CO;2· OSTI ID:6585391

Hofmann, D J; Rosen, J M

Balloonborne aerosol particle counter measurements are used in studying the stratospheric sulfate layer at Laramie, Wyoming, during 1978 and 1979, a 2-year volcanically quiescent period in which the layer appears to have been in a near equilibrium background state. Subtracting the background aerosol concentration from data obtained during an earlier volcanically active period indicates that the actual decay rate of volcanic aerosol is over 30% faster than one would obtain without this correction. At background, the aerosol size distribution is found to remain remarkably constant between the tropopause and an altitude of approx.25 km, with a sudden transition to a distribution dominated by smaller particles above this altitude. The observations, in some respects, compare favorably with equilibrium one-dimensional stratospheric aerosol models and thus to some extent support the concept of relatively inert tropospheric sulfurous gases, such as carbonyl sulfide and carbon disulfide, as the main background stratospheric aerosol sulfur source. Models which incorporate sulfur chemistry are apparently not able to predict the observed variation of particle size with altitude. The 2-year background period is not long enough in itself to establish long-term trends. The eruption of Mt. St. Helens in May 1980 has considerably disrupted the background stratospheric aerosol which will probably not recover for several years. A comparison of the 1978--79 observations with Junge's original measurements made some 20 years earlier, also during a period void of volcanic perturbations, does not preclude a long-term increase in the background stratospheric aerosol level.

• Research Organization: Department of Physics and Astronomy, University of Wyoming, Laramie 82071
• OSTI ID: 6585391
• Journal Information: J. Atmos. Sci.; (United States), Journal Name: J. Atmos. Sci.; (United States) Vol. 38:1; ISSN JAHSA
• Country of Publication: United States
• Language: English

Related Subjects

510200* -- Environment
Terrestrial-- Chemicals Monitoring &amp; Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOLS
ATMOSPHERIC CHEMISTRY
CHALCOGENIDES
CHEMISTRY
COLLOIDS
DISPERSIONS
EARTH ATMOSPHERE
LAYERS
NORTH AMERICA
OXYGEN COMPOUNDS
PARTICLE SIZE
ROCKY MOUNTAIN REGION
SIZE
SOLS
STRATOSPHERE
SULFATES
SULFIDES
SULFUR COMPOUNDS
USA
VOLCANOES
WYOMING