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The evolution and dynamics of an oceanic The evolution and dynamics of an oceanic quasi-linear convective system occurred on Sept. quasi-linear convective system occurred on Sept.
10, 2004 over the Taiwan Strait10, 2004 over the Taiwan Strait
The evolution and dynamics of an oceanic The evolution and dynamics of an oceanic quasi-linear convective system occurred on Sept. quasi-linear convective system occurred on Sept.
10, 2004 over the Taiwan Strait10, 2004 over the Taiwan Strait
Zhao KunZhao Kun1,21,2 and and Ben Jong-Dao JouBen Jong-Dao Jou11
11Department of Atmospheric Sciences, National Taiwan University, Taipei, TaiwanDepartment of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan22The key laboratory of Mesoscale Severe Weather, Department of Atmospheric SciencesThe key laboratory of Mesoscale Severe Weather, Department of Atmospheric Sciences
Nanjing University, Nanjing ChinaNanjing University, Nanjing China
Oct.Oct. 331, 2001, 20066 BoulderBoulder
Zhao KunZhao Kun1,21,2 and and Ben Jong-Dao JouBen Jong-Dao Jou11
11Department of Atmospheric Sciences, National Taiwan University, Taipei, TaiwanDepartment of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan22The key laboratory of Mesoscale Severe Weather, Department of Atmospheric SciencesThe key laboratory of Mesoscale Severe Weather, Department of Atmospheric Sciences
Nanjing University, Nanjing ChinaNanjing University, Nanjing China
Oct.Oct. 331, 2001, 20066 BoulderBoulder
OutlineOutline
BackgroundBackground, case description, case description Dual-Doppler synthsis (kinematic structure Dual-Doppler synthsis (kinematic structure
and thermodynamic/dynamic retrieval) and and thermodynamic/dynamic retrieval) and results aresults analysisnalysis
Discussion on origin, longevity, and the Discussion on origin, longevity, and the upscale growth of the mesovortexupscale growth of the mesovortex
ConclusionsConclusions
BackgroundBackground, case description, case description Dual-Doppler synthsis (kinematic structure Dual-Doppler synthsis (kinematic structure
and thermodynamic/dynamic retrieval) and and thermodynamic/dynamic retrieval) and results aresults analysisnalysis
Discussion on origin, longevity, and the Discussion on origin, longevity, and the upscale growth of the mesovortexupscale growth of the mesovortex
ConclusionsConclusions
Dual-Doppler AnalysisDual-Doppler Analysis1. RCTP and RCWF Radars, baseline 60km2. 1.5 hour period, total of 15 analysis volumns 3. Grid spacing: 1000m X 1000 m X 500m4. Domain: 60 km X 60 km X 16 km 5. Boundary conditions: W=0 at upper and lower
boundaries6. Horizontal field at echo top are lightly smoothed wit
h two pass Leise filter prior to divergence calculation and vertical integration for W
Thermodynamic Retrieval: Roux et al.(1990)
Houze et al. 1989
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0750UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Mature stage of mesovortex: after merge, a balanced feature?
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0709UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0703UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0657UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0646UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0640UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0634UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
V#3
V#1
V#2
V#1
V#2
CELL
Mesovortices in QLCS#1Mesovortices in QLCS#1
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0738UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0732UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0727UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)D
ista
nce
Nor
th o
f R
CW
F R
adar
(km
)
10m/s
0721UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Distance West of RCWF Radar (km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar (
km)
10m/s
0715UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
Vortex MergeV#1+V#3
Distance West of RCWF Radar (km)D
ista
nce
Nor
th o
f R
CW
F R
adar
(km
)
10m/s
0750UTC 2KM
-80 -75 -70 -65 -60 -55 -50 -45 -40 -35 -3010
15
20
25
30
35
40
45
50
55
60
dBZ
10
15
20
25
30
35
40
45
50
0634UTC
10m/s(dBZ) 2KM
A
A'
(a)
10
15
20
25
30
35
40
4510 15 20 25 30 35 40 45 50 10m/s
(dBZ) 4KM
(b)10 15 20 25 30 35 40 45 50
1
1
2
-2-1
0
0
0
0
00
0
1
23
-2
-1
2KMVertical Velocity Vertical Vorticity
(c)
-80 -70 -60 -5010
15
20
25
30
35
40
45
1
1
1
1
2
-2-1
0
0
0
1234
-2
-2
-1
-1 -1
4KMVertical Velocity Vertical Vorticity
(d)
-80 -70 -60 -50
Distance West of RCWF Radar(km)
Dis
tan
ce N
ort
h o
f RC
WF
Ra
da
r(km
)
V#1
V#2
V#1
10m/s(dBZ) 2KM
B
B'
(a)
10
20
30
40
50
6010 15 20 25 30 35 40 45 50 10m/s
(dBZ) 4KM
(b)10 15 20 25 30 35 40 45 50
1
1
1
11
2
2
23
3
34
-2
-2-1
-1
-1
-1
0
0
0
0
0
0
0
00
0
11
1
1
1
12
2
2
2
-1
-1
-1
-1-1
-1
2KMVertical Velocity Vertical Vorticity
(c)
-80 -70 -60 -50 -40 -3010
20
30
40
50
60
1
1
1
1
2
2
-2-1
-1
-1
-1
-1
0
0
00
0
0
0
11
1
1
1
1
1
1
1
2
2
2
3
3
-2
-2
-1
-1
-1
-1
-1
-1
-1
-1
4KMVertical Velocity Vertical Vorticity
(d)
-80 -70 -60 -50 -40 -30
Distance West of RCWF Radar(km)
Dis
tan
ce N
ort
h o
f RC
WF
Ra
da
r(km
)0709UTC
V#1
V#2
V#3
10m/s(dBZ) 2KM
C
C' (a)
10
20
30
40
50
6010 15 20 25 30 35 40 45 50 10m/s
(dBZ) 4KM
(b)10 15 20 25 30 35 40 45 50
1
1
1
11
22
23 3 4
-2-1
-1
-1
-1
-1
-1
0
0
0
0
0
0
0
0
0
00
0
0
0
1
1
11
1
1
2
2 3
3
-1
-1
-1
-1-1
2KMVertical Velocity Vertical Vorticity
(c)
-80 -70 -60 -50 -40 -3010
20
30
40
50
60
11
1
1
1 2
23
-1
-1
-1
-1
-1
-1
-1
0
0
00
0
0
0
0
0
0
0
0
1
1
1
1 1
1
1
1
12
2
22
3
34
-2
-2
-2
-2
-1
-1
-1
-1
-1
-1
-1
-1
-1
4KMVertical Velocity Vertical Vorticity
(d)
-80 -70 -60 -50 -40 -30
Distance West of RCWF Radar(km)
Dis
tan
ce N
ort
h o
f RC
WF
Ra
da
r(km
)0750UTC
V#3
Themodynamic Fields at 0750UTCThemodynamic Fields at 0750UTC
-80 -70 -60 -50 -4010
15
20
25
30
35
40
45
50
55
60
2
-80 -70 -60 -50 -4010
15
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35
40
45
50
55
60
6
-80 -70 -60 -50 -4010
15
20
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40
45
50
55
60
0
-80 -70 -60 -50 -4010
15
20
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30
35
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50
55
60
2km P’(0.1mb) T’(0.1o)
4km
W
W
L
L
Distance West of RCWF Radar(km)
Dis
tance N
ort
h o
f R
CW
F R
adar(
km
)
0750~0756UTC 2KM term-dynamic-dev
-5
(b) Dynamic
-80 -70 -60 -50 -40 -3010
15
20
25
30
35
40
45
50
55
60
Distance West of RCWF Radar(km)
Dis
tance N
ort
h o
f R
CW
F R
adar(
km
)
0750~0756UTC 2KM term-buoyancy-dev
-5
(c) Buoyancy
-80 -70 -60 -50 -40 -3010
15
20
25
30
35
40
45
50
55
60
Distance West of RCWF Radar(km)
Dis
tanc
e N
orth
of
RC
WF
Rad
ar(k
m)
0750~0756UTC 2KM term-total-dev
0
0
0
0
0
0
5
5
5
5
-25
-20-15
-15
-10
-10
-10
-10
-5
-5
-5
-5
-5
-5
-5
(a) Total
-80 -70 -60 -50 -40 -3010
15
20
25
30
35
40
45
50
55
60
Thermodynamic diagnose
For the vortex at mature stage
Cross sectionCross section
Heigh
t (km)
10m/s
5m/s
0750~0756UTC Reflectivity and Wind Field
(a)
0 5 10 15 20 250
2
4
6
8
10
dBZ
101520253035404550
0750~0756UTC Vertical velocity and Vertical vorticity
(b)
Distance (km)
Heigh
t (km)
0 5 10 15 20 250
2
4
6
8
10
Heigh
t (km)
10m/s
5m/s
0709~0715UTC Reflectivity and Wind Field
(a)
0 5 10 15 20 250
2
4
6
8
10
dBZ
101520253035404550
1
0
0709~0715UTC Vertical velocity and Vertical vorticity
(b)
Distance (km)
Heigh
t (km)
0 5 10 15 20 250
2
4
6
8
10
Heigh
t (km)
10m/s
5m/s
0634~0640UTC Reflectivity and Wind Field
(a)
0 5 10 15 20 250
2
4
6
8
10
dBZ
101520253035404550
0634~0640UTC Vertical velocity and Vertical vorticity
(b)
Distance (km)
Heigh
t (km)
0 5 10 15 20 250
2
4
6
8
10
A A’ B B’ C C’
1
1.5
2
2.5
3
3.5
4
4.5
5
Heig
ht(
km
)
(a) VORTEX#1
m
erg
er w
ith
cy
clo
nic
vo
rte
x#
2
Vertical Vorticiy 10 Sep. 2004 Vertical Velocity
1
1.5
2
2.5
3
3.5
4
4.5
5
Time (UTC)
Heig
ht(
km
)
(b) VORTEX#2
0634
0640
0646
0657
0703
0709
0715
0721
0727
0732
0738
0741
0744
0750
0756
Vertical Vorticiy 10 Sep. 2004 Vertical Velocity
VORTEX#1
VORTEX#3
Time-height profiles of the average vorticity and divergence within the vortex 1 and 3
He
igh
t(km
)
(a)
-2 -1 0 1 2
1
2
3
4
5
VOR
DIV
W
Vorticity budget 10-7s-2
He
igh
t(km
)
(b)
-15 -12 -9 -6 -3 0 3 6 9 12 15
1
2
3
4
5
HADV
VADV
STRTILT
LC
He
igh
t(km
)
(a)
-2 -1 0 1 2
1
2
3
4
5
VOR
DIV
W
Vorticity budget 10-7s-2
He
igh
t(km
)
(b)
-15 -12 -9 -6 -3 0 3 6 9 12 15
1
2
3
4
5
HADV
VADV
STRTILT
LC
0709UTC 0750UTC
DiscussionDiscussion
(1) Origin of vortex(1) Origin of vortex
14104 s
14104 s 141014 s
0657UTC 0750UTC
Stretching + Tilting (?)
(2) Longevity of Vortex(2) Longevity of VortexVortex Rossby RadiusVortex Rossby Radius (Frank 1983)(Frank 1983)Durran and Klemp (1982) Durran and Klemp (1982)
14
15
1
1055.6
1016.6
22
5.4
)5.2(6
s
sf
kmR
kmH
kmmsVt
2/112/1 )2()( fRVf
NHRd
T
2/1)]([z
gN
2/122
])ln
()/(1(
)/(1[
dz
dq
dz
dq
TC
L
dz
d
CpRTqL
RTLqgNm ws
ps
s
kmRdm
sNm
kmRd
sN
66
101.9
88
1029.1
13
12
TaipeiSounding
Dynamical large
MaKungSounding
kmRdm
sNm
kmRd
sN
29
108.4
73
1022.1
13
12
Dynamical small
Different Environment
(Kuo (Kuo et. al et. al
2004)2004)
0 0.5 1 1.5 2 2.50
0.5
1
1.5
2
2.5
0.8
0.7
0.7
0.7
0.8
0.7
0.7
0.7
/R1
0657UTC
0703UTC
0709UTC
0715UTC
(3) Upscale growth of (3) Upscale growth of
VortexVortex
Merger
A A SchematicSchematic diagram of the circulation and the vertical motion/ diagram of the circulation and the vertical motion/ trajectory atrajectory at mature stage of vortext mature stage of vortex ( (0750UTC)0750UTC)
0
2
4
6
8
10
He
igh
t(km
)
dBZ
10 20 30 40 50
Vm
N
B
10km
A
C
D
ConclusionsConclusions
TThe formation and evolution of thhe formation and evolution of thee mesovorices in mesovorices in QLCS#1 QLCS#1 dependdependss greatly on the greatly on the preexisting boundarypreexisting boundary, , in addition to in addition to the vertical wind shear and CAPEthe vertical wind shear and CAPE..
Contrary to previously documented MCV in QLCS whicContrary to previously documented MCV in QLCS which often accentuated by Coriolis force, this study provideh often accentuated by Coriolis force, this study provides an evidence that the small scale mesovorices originatins an evidence that the small scale mesovorices originating in the convective region can merge and grow upscale tg in the convective region can merge and grow upscale to result in a vortex of greater horizontal and vertical exteo result in a vortex of greater horizontal and vertical extent through an efficient merger process. nt through an efficient merger process.
The MCV at the mature stage exhibited The MCV at the mature stage exhibited somesome features of features of balanced vortex, which may induce a new updraft and cobalanced vortex, which may induce a new updraft and contribute the following convection.ntribute the following convection.