Stratospheric aerosol optical depth observed by the Stratospheric Aerosol and Gas Experiment 2: Decay of the El Chichon and Ruiz volcanic perturbations

Journal Article · Wed Mar 20 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JD02227· OSTI ID:5470975

Yue, G K; McCormick, M P ^[1]; Chiou, E W ^[2]

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1. NASA Langley Research Center, Hampton, VA (USA)
2. ST Systems Corp., Hampton, VA (USA)

The decay of the El Chichon perturbation to the optical depth of stratospheric aerosols at 1.02 {mu}m, and 0.453 {mu}m is calculated from the Stratospheric Aerosol and Gas Experiment II (SAGE II) data set for the period December 1984 to December 1988. It is found that the perturbed optical depths at middle and higher latitudes of both hemispheres exhibited an exponential decay superimposed by a seasonal oscillation with maximum and minimum occurring in local winter and local summer, respectively. Microphysical processes and variation of the tropopause height alone cannot explain this seasonal change of optical depth. The magnitudes of the exponential component at higher latitudes were, in general, larger than those at lower latitudes. For optical depths in tropical regions, the seasonal oscillations were small and were disturbed by the eruption of Nevado del Ruiz on November 13, 1985. The increase in ratio of optical depth at 0.525 {mu}m to that at 1.02 {mu}m from about 2.0 at the beginning of 1985 to about 3.5 at the end of 1988 indicates the average size of aerosol particles in the stratosphere is diminishing since the eruption of El Chichon. The l/e folding time for El Chichon decay derived from the SAGE II data set is in reasonably good agreement with those derived by other methods.

• OSTI ID: 5470975
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:D3; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
AEROSOLS
COLLOIDS
DATA ANALYSIS
DECAY
DISPERSIONS
EARTH ATMOSPHERE
GEOGRAPHICAL VARIATIONS
LATITUDE EFFECT
OPTICAL PROPERTIES
OSCILLATIONS
PARTICLE SIZE
PARTICLES
PARTICULATES
PHYSICAL PROPERTIES
SEASONAL VARIATIONS
SIZE
SOLS
STRATOSPHERE
TROPOPAUSE
TROPOSPHERE
VARIATIONS
VOLCANOES