Triple eyewall experiment of the 2012 typhoon Bolaven using cloud resolving ensemble forecast

(1)

“The

3

rd

Research

meeting

of

Ultrahigh

Precision

Meso

‐

Scale

Weather

Prediction”

Thu 21 Mar 2013

Thu.

21

Mar.

2013

Triple

eyewall experiment

of

the

2012

typhoon

“Bolaven”

using

cloud

resolving

ensemble

forecast

Seiji

ORIGUCHI, Kazuo

SAITO,

Hiromu SEKO,

Wataru MASHIKO

(MRI)

Tohru KURODA

(JAMSTEC)

(2)

JMA’s

Radar

image

(RISS)

04JST 26 05JST 26 06JST 26 07JST 26 03JST 26 07JST 26 08JST 26 09JST 26 10JST 26 11JST 26 12JST 26 13JST 26 14JST 26 _15JST15JST ₂₆26 16JST 26 17JST 26 18JST 26 19JST 26 20JST 26 21JST 26 Nago station 15JST; Outer eyewall 18JST; Middle eyewall 18JST 26 20JST 26 21JST 26 18JST; Middle eyewall 20JST; Inner eyewall 21JST; Center position of typhoon

(3)

Surface

observation

data

(Nago station)

26 – 27 Aug 2012

40

1020

Sea

level

pressure

Maximum

instantaneous

wind

velocity

Wind

direction(36dir)

26

27

Aug

2012

Wind peak; 1530JST

Wind

peak;

1830JST

hPa

m/s

dir

Local maximum wind velocity

35

1000

1010

Wind

peak;

1530JST

p

;

Local maximum wind velocity

caused by outer rainband Local maximum wind velocity

caused by outer rainband

25

30

980

990

15

20

960

970

10

15

940

950

Wind

peak;

2010JST

0

5

920

930

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Difference between minimum sea level pressure(2116JST)

and minimum of maximum instantaneous wind velocity (2149JST) 826010 0 826020 0 826030 0 826040 0 826050 0 826060 0 826070 0 826080 0 826090 0 826100 0 826110 0 826120 0 826130 0 826140 0 826150 0 826160 0 826170 0 826180 0 826190 0 826200 0 826210 0 826220 0 826230 0 827000 0 827010 0 827020 0 827030 0 827040 0 827050 0 827060 0 827070 0 827080 0 827090 0 827100 0 827110 0 827120 0 827130 0 827140 0 827150 0 827160 0 827170 0

JST

(4)

Surface

observation

data

(Nago station)

Approaching period,

～

21JST 26 Aug

40 1020

Sea level pressure Maximum instantaneous wind velocity Wind direction(36dir)

Approaching

period,

21JST

26

Aug

hPa

m/s

dir

About

120km

35 1000 1010 25 30 980 990

About

50km

20 960 970 10 15 940 950 960

About

10km

0 5 920 930 940 0 920 397.6 389.4 381.3 373.1 364.9 356.7 348.6 340.4 332.2 324.0 315.9 307.7 299.5 291.3 283.2 275.0 266.8 258.6 250.5 242.3 234.1 225.9 217.8 209.6 201.4 193.2 185.1 176.9 168.7 160.5 152.4 144.2 136.0 127.8 119.7 111.5 103.3 95.1 87.0 78.8 70.6 62.5 54.3 46.1 37.9 29.8 21.6 13.4 5.2

km

(5)

JMA’s

Radar

image

(RISS)

04JST 26 05JST 26 06JST 26 07JST 26 03JST 26 07JST 26 08JST 26 09JST 26 10JST 26 11JST 26 12JST 26

Targeting

period

of

ensemble

experiment

13JST 26 14JST 26 _15JST₂₆ 16JST 26 17JST 26 19JST 26 18JST 26 20JST 26 21JST 26 Nago station 15JST; Outer eyewall 18JST; Middle eyewall 18JST; Middle eyewall 20JST; Inner eyewall 21JST; Center position of typhoon

(6)

Ensemble

experiment

under

the

changed

physical

conditions

・

Case1

10km

（

789x251

）

→

2km

（

400x400

）

[10km:

2mom3iceCMF+KF,

MYNN3, 2km:

2mom3iceCMF,

MYNN3]

3

・

Case2

5km

（

789x251

）

→

1km

（

800x800

）

[5km:

2mom3iceCMF,

MYNN3, 1km:

2mom3iceCMF,

deardorff]

2

・

Case3

5km

（

789x251

）

→

1km

（

800x800

）

[5km: 2mom3iceCMF+KF MYNN3 1km: 2mom3iceCMF deardorff]

1

[5km:

2mom3iceCMF+KF,

MYNN3, 1km:

2mom3iceCMF,

deardorff]

・

Case4

2km

（

800x800

）

5

[2km:

2mom3iceCMF,

MYNN3]

・

Case5

2km

（

800x800

）

4

2km

（

800x800

）

[2km:

2mom3iceCMF,

deardorff]

・

Case6

（

）

（

）

4

2km

（

1800x1440

）

→

500m

（

3000x3000

）

[2km:

2mom3iceCMF,

deardorff, 500m:

2mom3iceCMF,

deardorff]

(7)

Experimental

conditions

of

Case3

＜

Ensemble forecast

＞

＜

Model settings

＞

8/25 12UTC (FT00) 12UTC (FT24) 00UTC (FT36) 00UTC (FT12)

＜

Ensemble

forecast

＞

5km‐forecast 1km‐forecast Model JMA‐NHM

＜

Model settings

＞

18UTC (FT24) 06UTC (FT12)

Resolution 5km, Member 11, Forecast Time 36hr 18UTC

(FT00)

Resolution ・Grid size 5km ・721x577x50 1km ・800x800x60

Time step 24(sec) 4(sec)

Meso anal sis (NHM 4DVAR) Self‐nest (FT12) _(FT24)

Resolution 1km, Member 11, Forecast Time 24hr (FT00)

Initial condition (CNTL)

Meso analysis (NHM‐4DVAR) Resolution 5km (Inner‐loop 15km,

Increment method 5km, Window 3hr)

FT=06 of 5km forecast Boundary condition (CNTL) GSM forecast (interval 1hr) 5km forecast (interval 1hr)

Initial condition Meso analysis + perturbation FT=06 of 5km

Analysis term 8/26 04JST～8/26 09JST(6hr)

Initial condition (ENS)

Meso analysis perturbation

of JMA 1 week forecast

FT 06 of 5km forecast Boundary condition

(ENS)

GSM forecast + perturbation

of JMA 1 week forecast

5km forecast (interval 1hr)

Member 11(CNTL+ENS)

＜

Model

domain

＞

1km‐forecast

Treatment of density Full compressibility

Basic equations Elasticity ・Nonhydrostatic・Solution of HE‐VI

Cloud microphysics ・ Convective scheme

2‐moment 3‐ice bulk method

＋Kain‐Fritsch scheme 2‐moment 3‐ice bulk method Layer ・Turbulent

scheme MYNN Level3 Deardorff(1980)

(8)

Reproducible

criteria

of

multiple

eyes?

・

There

aren’t

objective(numerical)

evaluation

method

or

common

indicator

between

researchers.

・

Therefore,

we

think

the

following

2

criteria.

●

We

don’t

decide

by

shape

of

precipitation

distribution

of

the

short

time.

We

judge

by

shape

of

updrafts

or

water

substances(

Qc+Qr

+Qi+Qs+Qg)

between

1km

and 5km AGL and if ring shape of updrafts or water substances keeps about 6

and

5km

AGL,

and

if

ring

shape

of

updrafts

or

water

substances

keeps

about

6

hours,

we

define

as

eyewall structure.

●

E

h

t f i

h

i l

it

t

ff f

th

h t ti

if i

●

Even

when

a

part

of

ring

changes

spiral

or

it

cuts

off

for

the

short

time,

if

ring

shape

of

updrafts

or

water

substances

keeps

overall

between

1km

and

5km

AGL,

(9)

Radar

P01

P02

P03

P04

P05

Precipitation

1hr(prec1)

・

Water

substance(tw=lw+iw)

・

Updraft(w)

FT=03

Surf

Surface(Nago) and Radar

observation Radius of eyewall; About 10km, About 50km, About 120km Z*=3.72km 1km Ensemble forecast Inner eyewallweak About 10km

Middle eyewallstrong About 50km

Outer eyewallmoderate

Z*=3.87km

M

M01

01

M02

M03

M04

M05

CNTL

About 120km Surf Z*=3.72km * k Z*=3.87km

(10)

Analysis

method

of

triple

eyewall

～

Estimation

of

center

position

～

●Braun’s method 2002 CP_m; Position decided by minimum surface pressure(Psea_m) CP_b; Position decided by Braun’s method

At fixed time Center position of ring

At fixed time CP_m At fixed time p g (Geometric center) CP_m At fixed time CP_b CP_b Width; 1km CP_m CP_b t1 t2 t3 t4 t5 t6 t1～t6

Sr; Standard deviation(Psea) in ring of radius r and width 1km

①_{C l l ti} _{f S} _t _{i hb h} _d _iti

Ring's oscillation occurs

for each forecast time

Ring is fixed for each forecast time. Consistency with temperature and wind ①_Calculation_of_{Sp at}_neighborhood_position

②CP_b decided by position of minimum value of Sp

Results

depend

on

the

determining

method

of

the

center

position,

therefore

we

decided

optimum

position

from

Braun‘s

method

2002.

(11)

Analysis

results

of

triple

eyewall

～

Estimation

of

center

position

～

Comparison of CP_m and CP_b for FT=01～06 (11member) Comparison of Psea_m and Psea_b for FT=01～06 (11member)

Different about maximum 6km between CP_m and CP_b

920.0hPa

920.0hPa 925.0hPa

Radius of inner eyewall is about 10km. So, if we don’t correct center position

(12)

Analysis

method

of

triple

eyewall

～

Averaged

physical

element

～

Physical

element

averaged

in

the

ring

region

of

radius

every

1km(from

1km

to

600km)

and

width

1km.

Y

vt

vr

R

・〈

vt

m

〉

t

・〈

vr

m

〉

t

・〈

vel

m

〉

t=

〈

(Vt+Vr)

1/2

|m

〉

t

・〈

w

m

〉

t

1km

・〈

w

m

〉

t

・〈

tt

m

〉

t

・〈

lw

m

〉

t=

〈

(Qc+Qr)|m

〉

t

・〈

iw

m

〉

t=

〈

(Qi+Qs+Qg)|m

〉

t

Center position decided

by Braun’s method 2002

*

m

:

Spatial

average

of

*

〈

*

〉

t

:

Temporal

average

of

_*

X

r

～

600km

Average

region

(13)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(14)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(15)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(16)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(17)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(18)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(19)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(20)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(21)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(22)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(23)

Analysis

results

of

triple

eyewall

～

Averaged

physical

element

～

(24)

vel

velm

Radius

of

local

maximum

wind

speed

at

10m

AGL Each

forecast

time

FT=01 FT=02 FT=03 FT=04 FT=05 FT=06 vr vrm vt vtm vvttm_1 vt vtm_2

Eye_in Eye_in _{Eye_in} _{Eye_in}

Eye_in

Eye_out _{Eye_out} Eye_out

Eye_md Eye_md Eye_md Eye_md Eye_md Eye_md

(25)

Radius

of

local

maximum

wind

speed

at

10m

AGL Each

member

vvttm_1 CNTL P01 P02 P03 P04 P05 Eye in Eye_in CNTL P01 P02 P03 P04 P05 y _ vt vtm_2 Eye_md Eye_md

Eye_md Eye_md Eye_md Eye_md

Eye_out Eye_out Eye_out

vvttm_1

M01 M02 M03 M04 M05

Eye_in

Eye_in Eye_in

As forecast time passed, the radius of local maximum wind speed(Eye_md) is reduced.

vt

vtm_2

Eye out Eye out

Eye_md

Eye_out

Eye_md _{Eye_md} Eye_md Eye_md

(26)

Conceptual

figure

of

triple

eyewall from

1km

ensemble

forecast

results

T1215(

T1215(Bolaven

Bolaven))

Z

vr

10

～

12km

vt

w

vt

6km

vt

vr

R

10km

50km

120km

vr

(27)

Future

Plan

●

We

will

continue

the

experiment

of

Case6

(2km

1800x1440

→

500m

3000x3000).



If

2km

or

500m

forecast

results

have

high

reproducibility

about

triple

eyewall,