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Meteorology seminar

Meteorology seminar. 2004.9.3. 1. Daisuke NAITO. 2. Mamami NOMURA. Miyakojima island. 台風. 梅雨. GAME HUBEX ’ 98- ’ 99. X-BAIU ’ 99, ’ 01, ’ 02. 長江下流域 ’ 01-’02. LAPS/CREST ’ 03- ’ 04. TAMEX ’ 87. Baiu season ( early ). SCSMEX ’ 98. Baiu season ( later ).

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Meteorology seminar

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  1. Meteorology seminar 2004.9.3 1. Daisuke NAITO 2. Mamami NOMURA

  2. Miyakojima island

  3. 台風 梅雨

  4. GAME HUBEX ’98-’99 X-BAIU ’99,’01,’02 長江下流域 ’01-’02 LAPS/CREST ’03-’04 TAMEX ’87 Baiu season ( early ) SCSMEX ’98 Baiu season ( later )

  5. Observation at Okinawa ( 13 May – 26 June 1987 ) Radar ・MRI Doppler radar ( X-band ) ・ODA radar ( C-band ) 　*ODA = Okinawa Development Agency Other ・Sounding ( at NAHA )

  6. AMTEX ’74-’75 Air Mass Transformation Experiment 14–28 Feb 1974 and 1975 ・Boundary layer ・Flux over the ocean ・Medium-Scale Depression (Saito1977) ・Precipitation (Takeda 1979) There are no observation around Miyakojima-island at Baiu/Meiyu season.

  7. Evolution of the Kinematic Structure within a Meso-β-Scale Convective System in the Growing and Mature Stages Monthly Weather Review 1991 Volume 119 2264 - 2676 KENJI AKAEDA, TATSUO YOKOYAMA, AKIRA TABATA, MASAHITO ISHIHARA AND HITOSHI SAKAKIBARA

  8. One meso-β-scale convective system One or severalmeso-β-scale convective system Introduction Cloud Cluster Squall cloud cluster Nonsquall cloud cluster

  9. We are not understand the structure and the time variation of the convective system in a cloud cluster. Ogura et al.(1985) Propagating mesoscale convective system ( in a early stage) Cloud cluster Stationary mesoscale convective system ( in a later stage) Akaeda et al.(1987) The distribution of convective system changed depending on cloud clusters evolutionary stages.

  10. Objects The structure and evolution of a meso-β-scale convective system (Time variation) are analyzed. My motivation in this paper ・Characteristic of the convection around Okinawa Similar to convection around Miyako or not ? ・Technique of single Doppler analysis

  11. Data Volume scan and RHI ( 7 min interval? ) ・MRI Doppler radar ( X-band ) ・ODA radar ( C-band ) PPI reflectivity data ( 5 min interval ) ・GMS hourly IR images ・Surface weather map ( 09JST 6 June 1987 ) ・Sounding ( at NAHA ) ( 21JST 5 June 1987 and 09JST 6 June 1987 )

  12. Synoptic situation 09JST 6 June 1987

  13. Low θe TIME

  14. before during CAPE 567m2/s2 LFC 763hPa LCL 986hPa

  15. before before Moderate shear Bulk Richardson number = 27 during during Lowest levels - southeast Lower levels - northwest Mid to upper levels - southwest

  16. The meso-β-scale convective system OKINAWA Observation area of ＭＲＩ radar

  17. STAGE 1 STAGE 1 STAGE 2 7m/s STAGE 2 MRI Doppler radar

  18. MRI radar B-type A-type Moving cells Stationarycells Northeastern part of the line Southwestern part of the line Location Almost stationary Northeastward at the speed 5.5m/s Movement Not regular Southwest side of the old cell Evolution STAGE 1 Nonpropagatingstage (line shape) Outermost contour 45dBZ Interval 5dBZ

  19. Rear inflow Reflectivity(dBZ) Doppler velocity(m/s) 減衰 斜線部：遠ざかる速度 白抜き：近づく速度 :convergence :divergence

  20. C-type Moving cells Central part of the system Location East-northeastward at the speed 4.5m/s Movement Southeast side of the old cell Evolution STAGE 2 Propagating stage (convex shape)

  21. Rear inflow Outflow Gust font Reflectivity(dBZ) Doppler velocity(m/s) 減衰

  22. A3 C1

  23. Conclusion

  24. Surface condition( 21JST 5 June ) 23.6℃、90％ CAPE 567m2/s2 Surface condition( 05JST 6 June ) 25.0℃、90％ CAPE 1463m2/s2 Discussion Maximum updraft – near 30m/s (CAPE 567m2/s2 ) Wmax = (2*CAPE)1/2 = 33.6m/s So large!! The sounding did not represent prestorm environment.

  25. I will try soon! For my study Characteristic of the convection around Okinawa ・Very strong reflectivity ( over 50dBZ ) ・Low LCL( the lowest layer is moist ) Technique of single Doppler analysis ・Very useful for my study

  26. Akaeda et al 1987 Ogura et al 1985 対流雲の発達や内部の詳細な構造の時間変化について調べた ものはない。

  27. Temperature drop(３℃) Pressure rise 通過 Gust front from the north MRI Doppler radar

  28. 減衰 通過 TIME MRI Doppler radar

  29. Time variation of echo area stage2 stage1 In stage2 , the strong echo maintained their area and the system was long-lived. The formation of a squall-line-type circulation is important in maintaining a strong system.

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