The Research Of The Blocking Process Resulting From Interaction Tetween Barotropic And Baroclinic Enstrophy

Using the baotropic and baroclinic decomposition,this paper firstly studys the character of barotropic and baroclinic flow fields in blocking process.Results shows that in the block shaping stage,the baroclinic flow field is converted towards barotropic flow field;In the maintaining stage ,the barotropic flow field reach the strongest;In the declining stage,the barotropic flow field begins to change towards the baroclinic flow field.The research of barotropic and baroclinic enstrophy indicates that during the course of Okhotsk and Ural mountain blocking,enstrophy increases instably in the blocking shaping stage;In the maintaining stage,it reachs the highest;and in the declining stage.it decreases instably.But to the spreading direction, there has difference between Okhotsk and Ural mountain blocking,enstrophy of the former develops from east-north to west-south accompanying blocking forming.and then spreading from west-north to east-south with blocking declining;While the last,its enstrophy increasing from side of east-north and west-south of blocking field following block formation.then decreases from the direction of west with blocking degradation.The equation of barotropic and baroclinic enstrophy reveals the evolvement mechanism of barotropic and baroclinic enstrophy:Flux and transformation mechanism are vital important in the whole course of Okhotsk and Ural mountain blocking.The flux mechanisn sparks the exchange of barotropic and baroclinic enstrophy,and transformation mechanism motivate the development of barotropic enstrophy,so stimulating evolvement of barotropic and baroclinic flow field.The analysis of flux and transformation item gives that:The transportation of baroclinic vorticity under influence of zonal baroclinic wind has great effect on the shaping and maintaining of blocking.The net transportation of barotropic enstrophy under control of barotropic zonal wind and transportation of mixing enstrophy under control of baroclinic wind also have the same importance in the procress of Okhotsk blocking;While in the Oral mountains blocking,the transportation of baroclinic vorticity under influence of zonal baroclinic wind has great effect on the maintaining and declining of blocking.And the transportation of baroclinic vorticity with the meridional baroclinic wind is vital in the shaping of blocking.The transportation of barotropic enstrophy under influence of meridional barotropic wind and the transportation of mixingenstrophy under influence of baroclinic wind also have key contribution.