1. A Lagrangian Trajectory View on Transport and Mixing Processes between the Eye, Eyewall, and Environment Using a High-Resolution Simulation of Hurricane Bonnie Cram et al. 2007:J. Atmos. Sci.,64, 1832~1856

2. Introduction

3. Model setup and overview Bonnie simulation MM5 V3.4 ResolutiongridsPBLCumulus scheme MP scheme Model time UTC (start) DO136 km91x91x27BlackadarGrellGoddar36 h1998-08-22 1200 DO212 Km160x160x 27 BlackadarGrellGoddar36 h1998-08-22 1200 STEP1:(hourly output) MM5 V3.4 ResolutiongridsPBLCumulus scheme MP scheme Model time UTC (start) DO36km255x255x 27 BlackadarNOGoddar30 h1998-08-22 1800 DO4 (moved grid) 2 Km266x266x 27 BlackadarNOGoddar30 h1998-08-22 1800 STEP2:(hourly output; Using the outer domain(Do1,2) outputs to initial conditions) a. Experimental design.

4. The intensity of Bonnie The black solid line is the central surface pressure. The gray solid line is the maximum tangential wind speed The gray dash line is the averaged tangential wind speed

5. b. Summary of simulated structure (Braun et al. 2006) 1.The northwesterly environmental deep layer vertical shear. (200-850 mb) 2.Simulated radar reflectivity exhibits an asymmetric storm structure consist with the influence of northwesterly vertical wind shear. (V~12m/s) 3.The horizontal profile of the radial wind. 4.The vertical profile of Bonnie Hurricane. The dotted line is the radius of maximum mean tangential wind. The shadow is positive values. The solid line is negative values. Hot tower

6. HθeHθe Gray shading denotes azimuthally averaged relative humidity greater 90 %. The dash line is the radius of maximum averaged tangential wind as a function height

7. Using of trajectories to study transport, stirring, and mixing process with the vortex a. The low-level eye-eyewall interaction 1) The trajectory sample. 2) Transport form the low-level eye to the eyewall. 3) Evidence of superintensity mechanism. b. Eye inflow trajectories and replenishment of the θe reservoir. 1) The trajectory sample. 2) Low-level eye mass replacement. 3) Superintensity mechanism maintained. c. The upper-level eyewall interaction. 1) The trajectory sample. 2) The containment vessel hypothesis reviewed. 3) Evidence of upper-level eye mass recycling. d. Ventilation of the TC by the midlevel environment. 1) The trajectory sample. 2) Environmental entrainment. 3) Ventilation illustrated.

8. a. The low-level eye-eyewall interaction The eyewall : On the RMW with azimuthally averaged vertical velocity greater than 0.25 (m/s) and RH greater than 90%. The low-level eye: Inside the RMW and near the storm center with θe ≧ 370 K. (Z<1 Km) Averaged vertical velocity near the center is less than 0.25 m/s. (Z=1.1 Km) The eye at mid- to up level: Inside the RMW with W 5.5 Km) 2. Transport from the low-level eye to the eyewall. T=15-20 h, Forward trajectory, R < 15 Km, initial height = 453 m 1. The trajectory sample. (case I)

9. Black dot is that trajectories encounter the eyewall below 1.5 Km Gray dot is that trajectories encounter the eyewall at 1.5 Km Vertical wind shear (a). θe (b). w as a function of height z =453 m,,total θe >= 370, trajectories=515 57%

10. 3) Evidence of superintensity mechanism. PM03: the low level eye air enhanced the θe of eyewall.

11. b. Eye inflow trajectories and replenishment of the θe reservoir. 1. The trajectory sample Forward trajectories seeded in the inflow layer converging on the storm center (case II) Histogram of trajectories of class II that are transported into the eye (θe>270K, z<2km). a.Seed level = 244 m b.Seed level = 121 m c.Seed level = 40 m

12. 2. Low-level eye mass replacement (a)Eye reservoir trajectories (41) (b)Stand eyewall ascent trajectories (78) (c)θe vs. height with the same trajectories (eye reservoir trajectories) (d)θe vs. height with the same trajectories (Stand eyewall ascent trajectories ) Maximum θe vs. eye residence time for the eye reservoir trajectories.

13. 3. Superintensity mechanism maintained Difference in θe between z=1.5 km and 500 m for the eye reservoir and stand eyewall ascent trajectories Note: The eye reservoir trajectories with high θe replenished the moist entropy low-level eye

14. c. The upper-level eyewall interaction. 1. The trajectory sample. Forward trajectories seeded within the eye above the inversion (z=1.1, 5.6 and 9.9 Km, case III) 2. The containment vessel hypothesis reviewed. (W98)

15. 3. Evidence of upper-level eye mass recycling Saturated-adiabatic process (600 ~ 900 mb) A shallow quasi-isothermal layer (800 ~ 850 mb) Z=5.6 Km (59%) Z=9.8 Km (76%)

16. Percentage of eye trajectories of class III seeded at each radius and at z= 453 m (solid line), 1.1 Km (dotted line), 5.6 Km (dash line), which stirred into the axisymmetric mean eyewall (Wavg>0.25(m/s), RH>90%)

17. d. Ventilation of the TC by the midlevel environment 1. The trajectory sample. Backward trajectories seeded across the eyewall and determine the source of that air. (To distinguish class IV trajectories; z =5 Km, 36< r <50 (Km), total trajectories=400) (a). Locations where trajectories encounter the eyewall plotted in (r,z) plane. (b). The same as (a) in (x,y) plane (c). The same as (a), but “x” is initial point of the case IV (d). The same as (b), but “x“ is initial point of the case IV Case I or II Case III Case IV

18. 3. Ventilation illustrated 2. Environmental entrainment form numbers Case I, IICase IIICase IV 40021311572 Case III entry point on downshear storm. Case IV entry point on upshear of the storm. downshear upshear Total numbers of case IV are 72

19. Conclusions Low-level : 1. The low-level eye is replenished by boundary layer parcels that slip underneath the eyewall updrafts to linger for some time in the eye. 2. The low-level trajectories with high θe enhanced the eyewall (case I and II). Mid-upper : 1. Very little air is stirred into the eye from the environment boundary layer. 2. The interaction of environment air with low entropy and the eyewall is hypothesized to waken the TC