Evolution Of Residual Circulation And Its Influence On Trace Component Distribution

Using European Center for Medium Range Weather Forecasts Interim (ERA-Interim) data, temporal-spatial structural switch and evolution character of the residual circulation derived from the improved transformed Eulerian-mean equation in different seasons during1979-2011was analyzed. Dynamic transport and residual force of stratospheric ozone and water vapour derived from transformed Eulerian-mean equation during1979-2011was analyzed. Using WACCM-3model, the residual circulation change was simulated with and without ozone change, temporal-spatial structural switch and evolution character of the residual circulation in ozone recovery scene was analyzed.The results show that:(1)The center of residual circulation upwelling in150hPa extends to more north in March, April and May(MAM) and in June, July and August(JJA), and reach to more south in September, October and November(SON) and in December, January and February(DJF) during1979-2011. The change in JJA and SON is most obvious; it extends0.92°/decad toward north in JJA and0.57°/decade toward south in SON respectively during1979-2011.(2)The residual circulation in troposphere observably strengthens in different seasons during1979-2011, but it weakens in circulation upwelling area near tropical and near tropopause.(3)Both of downward mass flux in high latitude of two hemispheres and upward mass flux in tropical near100hPa almost weaken in different seasons during1979-2011, except for downward mass flux in the Northern Hemisphere (NH) during JJA and SON.(4)The mean transport and chemical term contributes a majority of stratospheric ozone tendency, eddy transport decrease ozone in South Polar during South winter, reduce ozone hole due to chemical losing during South spring, and ensure following ozone recovery.(5)The vertical transport is primary in mean transport. The horizontal eddy transport control of eddy ozone transport. The strength of eddy transport is dependent on both of wave breakdown and stronger ozone meridional gratitude. The instability of ozone layer in South Polar cause eddy transport strengthening during South spring.(6)Stratospheric water vapour source from vertical mean transport and vertical eddy transport in tropical, maximum convection height is near50hPa. The water vapour was consumed by phase change near tropical tropopause. (7)The water vapour distribution in higher stratosphere is influenced by mean transport and chemical term. The positive and negative water vapour tendency arrays beginning from higher stratosphere, and transport path move toward north with high.(8) The producing of stratospheric cloud in South Polar is controlled by horizontal eddy transport, which provides abundant water vapour during polar vortex maintaining, it can reach to lOhPa.(9) Residual circulation strengthens in the South Hemisphere and weakens in the North Hemisphere when greenhouse gases in troposphere increase. The velocity of residual circulation decreases, air-mass transport by it increases and moving from south to north of residual circulation strengthens in ozone recovery scene.(10) The mass flux in stratosphere increase in greenhouse warming, but the trend in earlier stage is larger than that in later stage. The mass flux increases in100hPa and decreases in70hPa in ozone recovery scene.