Dynamical Analysis of the Role of Stratospheric Large Scale Circulation on the Stratospheric Ozone Depletion
Subject Areas : Geopolitic
Abbas Mofidi
1
(
ندارد
)
Keywords: Stratosphere, Stratospheric Ozone, Stratospheric Circulation, Planetary
, 
, Scale Rossby Waves, Polar Vortex, Brewer-Dobson Circulation, Quasi-
, 
, Biennial Oscillation, Tropopause, Stratospheric Sudden Warming, Ozone
, 
, Hole,
Abstract :
In order to recognize and understand the mechanism governing on variations anddecrease of stratospheric ozone, the dynamical characteristics of Middle atmospherespecially,atmospheric circulation and mass transport in the stratosphere wereinvestigated.The first, characteristics of stratospheric ozone such as it’s production andtemporal and spatial distribution of it has been noticed. Then, considering the veryimportant role of stratospheric circulation in distribution, variation and decrease ofstratospheric ozone, with presentation of a division of stratospheric circulation; meancharacteristics of zonal(consist of Polar Vortex, Surf Zone, QBO and summerhemisphere circulation) and meridional circulation(Brewer-Dobson circulation) hasbeen illustrated.In following, in order to explanation of stratospheric ozone depletion, trend oftemporal and spatial ozone decreasing were investigated. Finally, links between themost important dynamical components, i.e. Polar Vortex, Planetary Scale RossbyWaves, Stratospheric Sudden Warming, QBO and variations and depletion ofstratospheric ozone, illustrated.The results indicate that since 1980, the global mean of ozone decrease was about3% and the largest decreases have been observed over the polar regions of twohemispheres in spring.Stratospheric Polar Vortex has a key role in interannual variability of Total Ozoneand account a necessary precondition for ozone depletion and formation ofstratospheric ozone hole. Therefore, Shape, Area, intensity and Persistence of PolarVortex in two hemisphere is determining ozone decrease rate and the maximum arealcoverage of ozone hole.Dynamical forcing from troposphere is the major source of stratospheric variationsand upward propagation of planetary waves in addition to the occurance Brewer-Dobson circulation and Stratospheric Sudden Warming, is controlling the temporal andspatial distribution of total ozone and decrease and increase of stratospheric ozone.Hence, the circulation of the winter stratosphere is strongly influenced by verticallypropagating forced planetary waves and rate of planetary waves activity in stratosphereand their interaction with dynamical components such as QBO and Polar Vortex,additionally control of Brewer-Dobson circulation and temperature ratio, isdetermining transport and interannual variability of stratospheric ozone.
