Transport into the south polar vortex in early spring

Journal Article · Thu Nov 30 04:00:00 EST 1989 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JD094iD14p16779· OSTI ID:7251812

Hartmann, D L ^[1]; Heidt, L E ^[2]; Loewenstein, M; Podolske, J R; Vedder, J; Starr, W L; Strahan, S E ^[3]

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1. Univ. of Washington, Seattle (United States)
2. National Center for Atmospheric Research, Boulder, CO (United States)
3. NASA Ames Research Center, Moffett Field, CA (United States)

Data collected during the Airborne Antarctic Ozone Experiment during August and September 22, 1987 show conclusively that a photochemical sink and not transport caused the ozone decline during that time. During the period August 23 to September 22, mixing ratios of trace constitutents with long lifetimes remained relatively constant for fixed potential temperature and latitude. Over the same period the ozone mixing ratio declined by more than 50% inside the polar vortex near 18 km altitude. This observation alone requires a substantial photochemical sink of ozone. The conservative tracer data indicate that the Lagrangian mean vertical velocity cannot have been upward inside the polar vortex where the ozone hole appeared. Tracer and ozone gradients in the region from 54{degree} to 72{degree}S imply that ozone could be transported into the polar vortex during the spring season. Observed gradients of conserved tracers with respect to latitude and potential temperature are used to deduce a relationship between meridional mixing on potential temperature surfaces and mean diabatic descent in the vortex. The observed gradients and time tendency of ozone are then used to infer the magnitude of the effect of ozone transport in mitigating the springtime ozone decline, using an assumed best guess heating rate of 0.2K/d. It is estimated that ozone transport increased the requirement for a photochemical sink by about 20% {plus minus} 10% near the 425-K potential temperature level during the period of the 1987 experiment, so that transport from other latitudes or heights had a relatively weak influence on the development of the ozone hole in 1987.

• OSTI ID: 7251812
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 94:D14; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

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29 ENERGY PLANNING, POLICY, AND ECONOMY
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54 ENVIRONMENTAL SCIENCES
540120* -- Environment
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ANTARCTIC REGIONS
ATMOSPHERIC CHEMISTRY
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
CHLORINE COMPOUNDS
CHLORINE OXIDES
HALOGEN COMPOUNDS
HOLES
LAYERS
LOSSES
MASS TRANSFER
MIXING
OXIDES
OXYGEN COMPOUNDS
OZONE
OZONE LAYER
PHOTOCHEMICAL REACTIONS
POLAR REGIONS
SINKS
VORTICES