Title Page
Contents
요약 10
I. Introduction 12
II. Experimental design and Model 15
1. The structure of the idealized vortex 15
2. Environmental field 22
3. Boundary conditions 24
4. The numerical model 26
III. Results 28
1. Response of vortices 28
1.1. The track change of vortex 28
1.2. The intensity change of vortex 31
2. Analysis of moving vortex 35
2.1. Flow induced by SST field 35
2.2. The mechanism for moving vortex 43
2.3. Potential vorticity of moving vortex 46
3. Supplementary numerical experiment 51
3.1. Introduction 51
3.2. The result of supplementary numerical experiment 54
IV. Summary and Conclusion 56
Reference 59
Table 2-1. The information for constructing the idealized vortex. 20
Table 2-2. The model configurations and model parameterizations used in this study. 27
Fig. 2-1. The flowchart of the procedure for constructing the idealized vortex. 16
Fig. 2-2. The structure of axisymmetric idealized vortex of (a) tangential wind (unit= ms-1), (b) geopotential deviation (with long dashed contour; unit= m), and temperature deviation (with shading; unit= K). The contour interval is 1 ms-1 for tangential wind and 100 m²s-2 for geopotential deviation.(이미지참조) 21
Fig. 2-3. The profiles of environmental for (a) geopotential height (unit= m), (b) relative humidity (unit= %), and (c) temperature (unit= K) fields from Jordan’s (1958) mean hurricane season sounding in West Indies. 23
Fig. 2-4. The SST fields (shaded) with (a) constant SST (=28.5℃), (b) warmer SST to the south of vortex center, and (c) warmer SST to the north of vortex center. The contour lines are isobar at initial time and its interval is 4 hPa. 25
Fig. 3-1. The track of vortex center for (a) CTRL case, (b) Exp. 1 case, and (c) Exp. 2 case during 96 h. The track positions are shown at 6 h intervals (0~12 h, red; 18~24 h, orange; 30~36 h, yellow; 42~48 h, green; 54~60 h, blue; 66~72 h, navy; 78~84 h, purple; 90~96 h, black). The motion vector of the vortex for (d) CTRL... 30
Fig. 3-2. The time series of (a) central pressure (unit= hPa), and (b) maximum wind speed (unit= ms-1). The solid line indicates the result of CTRL case. The long dashed line and dot lines indicate the result of Exp. 1 case and Exp. 2 case, respectively.(이미지참조) 33
Fig. 3-3. The temporal variations of the average temperature anomalies (K) within 50 km from the vortex center of (a) CTRL case, (b) Exp. 1 case, and (c) Exp. 2 case. The contour interval is 1 K. 34
Fig. 3-4. The zonal averaged vertical section of the asymmetric temperature (contour) for (a) CTRL case, (b) Exp. 1 case, and (c) Exp. 2 case at 96 h. The horizontal axis represents a meridional distance from the position of vortex at initial time. The contour interval is 0.5 K. 38
Fig. 3-5. The zonal averaged vertical section of the asymmetric u-component (shaded) and v-component (contour) for the CTRL case. The horizontal axis represents a meridional distance from the position of vortex at initial time. The contour interval is 1 ms-1.(이미지참조) 39
Fig. 3-6. Same as Fig. 3-5 but for the Exp. 1 case. 40
Fig. 3-7. Same as Fig. 3-5 but for the Exp. 2 case. 41
Fig. 3-8. The time averaged vertical shear within 50 km from the vortex center during 48 h to 96 h. The solid line indicates the vertical shear of CTRL case. The long dashed line and dot lines indicate the vertical shear of Exp. 1 case and Exp. 2 case, respectively. 42
Fig. 3-9. Schematic of the potential interaction between an upper-level anticyclone (A) and low-level cyclone (C). The direction of propagation of the vortex is into the page. 45
Fig. 3-10. Potential vorticity fields in CTRL case at 24 h intervals. Contour interval is 0.001 K kg-1 m² s-1. The length and direction of arrow indicate the speed and direction of moving vortex at the lowest level, respectively.(이미지참조) 48
Fig. 3-11. Same as Fig. 3-10 but for the Exp. 1 case. 49
Fig. 3-12. Same as Fig. 3-10 but for the Exp. 2 case. 50
Fig. 3-13. The vertical shear for the supplementary numerical experiment. 53
Fig. 3-14. The track of vortex center for (a) Exp. 3, and (b) Exp. 4 case during 96 h. The track positions are shown at 6 h intervals (0~12 h, red; 18~24 h, orange; 30~36 h, yellow; 42~48 h, green; 54~60 h, blue; 66~72 h, navy; 78~84 h, purple; 90~96 h, black). The motion vector of the vortex for (c) Exp. 3 case, and (d) Exp. 4 case... 55