Dual-Aircraft Investigation of the Inner Core of Hurricane Nobert

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1 Dual-Aircraft Investigation of the Inner Core of Hurricane Nobert
Dual-Aircraft Investigation of the Inner Core of Hurricane Nobert. PARTⅡ: Mesoscale Distribution of ice Particles Houze, R. A., Jr., F. D. Marks, Jr., and R. A. Black, 1992: J. Atmos. Sci., 49, Speaker:Liou 2007/03/29

2 Introduction 層狀降水的冰粒子 來源在哪? 如何傳送? NOAA WP-3D雷達 資料如何收集? 資料如何分析?
對流降水區的降水有60%將在曾狀降水區

3 Data collection and analysis
Flight pattern. Radar reflectivity data Classification of particle images Mapping of ice-particle data Mapping of flight-path wind and vertical velocity data

4 Three-dimensional radar reflectivity structure
Eyewall echo pattern at 1-, 3-, 6-, and 9-km level. Vertical cross sections through the eyewall Vertical cross sections through the stratifrorm region outside the eyewall.

5 Mapping of ice-particle data obtained at 6-km level
Mass concentration Median volume diameter Number concentration Particle size Schematic pattern of ice-particle characteristics at the 6-km level

6 Relationship of vertical and horizontal air motion at flight level to precipitation and microphysical fields

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9 Trajectory analysis

10 Conclusions First large size: 眼牆上的強對流產生的冰雹
High concentration: 上升氣流所產生的冰晶(secondary ice production)和眼牆中的冰粒子靠著二次環流傳送到此處 Second large size: 由眼牆經過二次環流經過疊合過程所產生的large size

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12 0.55<2DC<1.05 2DC-medium (unit: mm) 1.05<2DC 2DC-large
2DC (cloud probe) 0.05<2DC< DC-small 0.55<2DC< DC-medium (unit: mm) 1.05<2DC DC-large 2DP (precipitation probe) 0.2<2DP< DP-small 2<2DP< DP-medium 4<2DP DP-large Black and Hallett (1986) columnar nearly round aggregates

13 Number of data sample.

14 底層為非對秤，在颱風西邊有最強的雷達迴波??9KM得眼牆有明顯的PLUME往外
色階深淺代表10、20、25、30、35、40dbz

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16 Precipitation typically forms high in the atmosphere where the temperature is below freezing. As ice crystals form aloft and fall toward the surface, they collect each other to form large snowflakes. As the snowflakes fall, they pass through a level where the temperature rises above freezing. When the snowflakes start to melt, they initially develop a water coating. Water is about 9X more reflective than ice at microwave wavelengths, so these large wet snowflakes produce a high reflectivity.

17 圖形類似，小於0.2mm的降水物質數量很小 位於6KM處，在0度線以上假設都為冰

18 0.55<2DC<1.05 2<2DP<4

19 因為層狀降水來自對流區而經過比較長時間的疊合作用而成長

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