meteorology seminar 2004.9.3 1. daisuke naito 2. mamami nomura
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SCSMEX ’98
GAME HUBEX ’98-’99
Baiu season ( early )
長江下流域 ’01-’02
X-BAIU’99,’01,’02
Baiu season ( later )
TAMEX ’87LAPS/CREST ’03-’04
Observation at Okinawa ( 13 May – 26 June 1987 )
・MRI Doppler radar ( X-band )
・ ODA radar ( C-band ) *ODA = Okinawa
Development Agency
Radar
Other
・ Sounding ( at NAHA )
AMTEX ’74-’75
Air Mass Transformation Experiment14–28 Feb 1974 and 1975
There are no observation around Miyakojima-island at Baiu/Meiyu season.
・ Boundary layer・ Flux over the ocean
・Medium-Scale Depression (Saito1977)・ Precipitation (Takeda 1979)
Evolution of the Kinematic Structure within a Meso-β-Scale Convective System
in the Growing and Mature Stages
KENJI AKAEDA, TATSUO YOKOYAMA, AKIRA TABATA, MASAHITO ISHIHARA AND
HITOSHI SAKAKIBARA
Monthly Weather Review 1991 Volume 119 2264 - 2676
Introduction
Cloud Cluster
Squall cloud cluster
Nonsquall cloud cluster
One meso-β-scale convective system
One or several meso-β-scale convective system
We are not understand the structure and the time variation of the convective system in a cloud cluster.
Ogura et al.(1985)
Cloud cluster
Propagating mesoscale convective system( in a early stage)
Stationary mesoscale convective system( in a later stage)
Akaeda et al.(1987)The distribution of convective system changed depending on cloud clusters evolutionary stages.
ObjectsThe 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
・MRI Doppler radar ( X-band )・ODA radar
( C-band )・GMS hourly IR images
・ Surface weather map ( 09JST 6 June 1987 )
・ Sounding ( at NAHA ) ( 21JST 5 June 1987and 09JST 6 June 1987 )
PPI reflectivity data ( 5 min interval )
Volume scan and RHI ( 7 min interval? )
Data
before
during
before
during
Lowest levels - southeast
Lower levels - northwest
Mid to upper levels - southwest
Bulk Richardson number = 27
Moderate shear
STAGE 1MRI radar
A-typeStationary cells
B-typeMoving cells
LocationSouthwestern part of the line
Northeastern part of the line
MovementNortheastward at the speed 5.5m/s
Almost stationary
EvolutionSouthwest side of the old cell
Not regular
Nonpropagating stage(line shape)
Outermost contour 45dBZInterval 5dBZ
STAGE 2Propagating stage(convex shape)
C-typeMoving cells
LocationCentral part of the system
MovementEast-northeastward at the speed 4.5m/s
EvolutionSoutheast side of the old cell
Discussion
Maximum updraft – near 30m/s (CAPE 567m2/s2 )
So large!!Wmax = (2*CAPE)1/2
= 33.6m/s
The sounding did not represent prestorm environment.
Surface condition( 21JST 5 June ) 23.6℃、 90%
Surface condition( 05JST 6 June ) 25.0℃、 90%
CAPE 567m2/s2
CAPE 1463m2/s2
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 I will try soon!