A further study of the tropical cyclone without parameterizing the effects of cumulus convection

Masanori Yamasaki
1983 Papers in Meteorology and Geophysics  
As a continuation of previous studies(Yamasaki,1977a,b)numerical experiments of axially symmetric tropical cyclones are performe(i.As in the previous studies,a fine resolu− tion model is used in which convective clouds are not parameterized but explicitly resolved. A recent advance in the computer has enabled us to deal with the tropical cyclone with realistic horizoptal scale even when a sufnciently small grid size is used.Although assumption of axial symmetry restricts very realistic
more » ... n of real tropical cydones,it seems that the numerical experiments have reveale(l many important aspects of the formation and intensi丘cation processes and the structures of the tropical cydone and their mechanisms. At the early stage before the tangential velocity attains about10ms『1,the area of convective activity and the vortex size expand with time because convection at the outermost part of the convective area propagates outward. Individual convective clouds are usuallyP organized as a convective system with a time scale of about3hours,which is referre(l to as mesoscale convection in this paper。As one mesoscale convection・weakens,another forms at some distance.As a result of successive formation,convective activity and rainfalI propagate outward or inward and persist for a long Period of time.A Iarge・scale(cyclone− scale)meri(iional circulation is intensifie(1by an ensemble of several mesoscale convections,
doi:10.2467/mripapers.34.221 fatcat:huk2cwelp5e5jbfpehr3ad664q