A long\|standing issue on the role of vertical shear and β\|effect on tropical cyclone intensity and structure is studied through a series of numerical experiments underdifferent vertical wind shears (VWS)inf\| and β\| planes using the fully compressible, nonhydrostatic tropical cyclone model\|TCM4. The result shows that: (1) When a TC is embedded in a relatively week VWS, the intensityof this TC will finally become a steady\|state, by researching the sensitivity of the steady\|state intensity to the VWS, we suggest that it may be more appropriate to discuss the threshold of a VWS for a TC to stay above a certain intensity (typhoon, tropical storm and tropical depression) instead of a threshold to determine whether a TC would weaken or intensify undera VWS.(2) In f\|plane, the vorticity advection are changed with height caused by vertical shear, which in turn produces low\|level convergence ahead of and to the left of the shear vector, with the air then rising in a cyclonic spiral, correspond to this, the outflow level exist a divergence region, producing convection and rain on the downshear left. (3) Planetary vorticity gradient (β\|effect) could also cause a certain asymmetric, when consideringthe superposition effect of β\|effect and VWS,the asymmetric is more than it cause individual by β\|effect or VWS, and the severe convection concentrate on the left front of the shear vector. (4) The eyewall replacement phenomena may have a certain degree of predictability because they appear to depend on the β\|effect and VWS.
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