Operational review on the 10-year (2003-2012) typhoon surveillance flight observation with dropsondes and their statistical feature of outer core in western Pacific region

Po-Hsiung Lin1 Chun-Chieh Wu1 Kun-Hsuan Chou2

1National Taiwan University2Chinese Culture University

� Part I:• Phases of DOTSAR Project• Operation Flow of DOTSTAR� Part II:� Some Statistics Numbers (2003~2012)� Characteristics of Typhoon Outer Core� eye crossing flights and Inner core of typhoon � Summary and next step

OUTLINE

Phases of DOTSAR Project

� Pre-Phase: 2002 summer (visiting NOAA/RHD, AOC)

� Phase 1 : 2003-2005 (NTU, supported by NSC)

� Phase 2: 2006-2012 (NTU, supported by CWB +

2008 TPARC + 2010 ITOP)

� Phase 3: 2013~ (TTFRI, supported by CWB)

Pre-Phase: 2012 NOAA/RHD, NOAA/AOC/G4Atlantic 2002 • TD EDOURAD• TD FAY

Phase 1 : 2003-2005Funding support by NSC

• Airplane owners: Japan Diamond Air Service, Taiwan AIDC• AIDC ASTRA Jet AVAPS setup• Interface for flight path making (Virtual Basics, Windows-Based) • Onboard flight-aid software (NTU-Madonna , NCAR-ASPEN) • 1st test flight: May 23, 2003• 1st typhoon mission: Dujuan (Sept. 1, 2003)

ASTRA (Gulfstream 100)

Windows Interface for flight path making (Virtual Basics)

Flight domain

Naha FIR

Philippines FIR

Operation Flow of DOTSTAR

DB 5~3 daysStorm Watch (CWB, NTU)

DB 3~2 daysFlight path making (NTU)Flight plan sending to NAHA, Philippines, HK FIR (AIDC)

DB 2~1 daysCrews Call (NTU)Decision making (Go or not) (NTU+CWB)

DB 5~2 hrsGround transportation Taipei---Taichung (NTU)

DB 2~1 hrsFinal ground check (AIDC + NTU)

DB 1hrMission + Weather briefing (AIDC + NTU)

DA 0~6hrsDrop + onboard code editing + voice communication (NTU, AIDC, CWB)

DB: Day BeforeDA: Day After

System Engineer

Code editor

Launcher + PI (visitor)

AVAPS operator

RD94 dropsonde

ASTRA (Gulfstream 100)

gate

toilet

Code

editor

launcher

SE

AVAPS

operator

Satcomm

PI / Visitor

internet

pilots

Onboard data processing

AVAPS (Airborne Vertical Atmospheric Profiling System )

RD94 dropsonde in-air data

SatcommFTP

TTFRI

CWB

Astra Jet flight Information

Madonna (2003-2006)

(realtime airborne and dropsondedata ploting & diagnosis system )

Britney (2007~)

(Bright tool for onboard enjoy)

AR-429 Bus-Card

Pilot console

Vaisala

NTU

ASPEN (Atmospheric Sounding Processing Environment )

DCF (Data Compress and FTP sending )

NTU

NCAR

Phase 1~3

� 2004 “e-Taiwan” Film by Government Information Office� 2008 ”T-PARC”� 2008 “National Geography” TV program� 2009 “NSC-50th” film program� 2010 “ITOP”� 2012 “Follow me” TV children program� 2013 Technical transfer from NTU to TTFRI

Some Statistics Numbers (2003-2012)

Dropsonde: 946/1051 (10% bad, most of this number contributed by old RD93 dropsonde before 2009)

Flights: 64TY : 49

The case-averaged track error statistics of 2003–2009 DOTSTAR cases at every 24-h forecast time for different periods.

Bars represent the case-averaged track error of control (NCEP-O) and denial (NCEP-N) forecasts (in km). The solid

line indicates the case-averaged track error improvement (in %) and the dashed line the number of cases in each

forecast time. The single (double) asterisk shown on the abscissa indicates that the forecast error difference between the

control and denial runs is statistically significant at the 90% (95%) confidence level. (Chou et al.,2011)

Dropsonde impact study by NCEP GFS 2003-2009 45 TCs (35 cases)

Improvement of track error 12~18%

13 13 13 13 55 55 55 55 82 82 82 82 114 114 114 114 140 140 140 140 167 167 167 167 221 221 221 221 13 13 13 13 67 67 67 67 87 87 87 87 115 115 115 115 151 151 151 151 177 177 177 177 244 244 244 244

0

50

100

150

200

250

300

0 (34) 12 (34) 24 (34) 36 (32) 48 (30) 60 (28) 72 (24)

track

erro

rs

(km

)

forecast hours (case no.)

TWRF_45_DP

TWRF_45_NODP

Dropsonde impact study by CWB-TWRF 2008-2012 22 TCs (34 cases)

增加dropsonde資料34個案，TWRF平均颱風路徑誤差改進 7.9%。

鄭浚騰, 陳得松,蕭玲鳳 ,黃康寧, 洪景山 ,馮欽賜 ,Xiang-Yu Huang, Hongli Wang, 葉天降(2013,天氣分析與預報研討會 )

Improvement of track error ~8%

Some Statistics Numbers (2003-2012) Distance to eye / dropsonde number

• 0-100 km (inner core) / 17• 100-300 km (outer core) / 314• 300-500 km / 399• > 500 km / 216

Target observation for sensitivity regions

Characteristics of Typhoon Outer CoreTangential velocity

DRUR

DLUL

DL: shallow and smallDR: deep and largerUR: maxi wind at ~1100m height and 1.4 times more than DL

1100m

Characteristics of Typhoon Outer CoreTangential velocity (UR)

DRUR

DLUL

light : strong (1 : 1.4 )

1100m

Typhoon intensity defined by CWB

DR

UR

DL

UL

In-situ measurement of wind speedby Aerosonde in Typhoon Longwang 2005 (Lin and Lee, 2008)

Characteristics of Typhoon Outer CoreRelative Humidity

DRUR

DLUL

600m

Compared with wind field, moisture profiles are more symmetric in outer core of typhoon

Characteristics of Typhoon Outer CoreRelative Humidity (UR)

DRUR

DLUL

light : strong (1 : 1.03 )

500m

Characteristics of Typhoon Outer CoreVirtual Potential TemperatureDR

UR

DLUL

500m

Compared with wind field, thermal profiles are more symmetric in outer core of typhoonUnstable level height is about ~ 500m height

Characteristics of Typhoon Outer CoreVirtual Potential Temperature (UR)

DRUR

DLUL

500m

Stability below 500m in different intensity of typhoon needs more study

eye crossing flights and Inner core of typhoon *2003 Melor

N

SN S N S

Comparison of vertical profiles between Inner core and outer core�lower and stronger windshear + more humid

DR

UR

DL

UL

• tangential wind : maximum speed close to 1000m height and asymmetric in quadrants (stronger at UR, weaker at DL)

• humidity : more symmetric than wind field • The profiles in different intensity of typhoons are under

studied. • More data from inner core should be collected

Summary and next step

Summary and next step

DORIS:A mini AXBT(airborne XBT) in same size of RD94 dropsondeis under developed by NTU, TORI and TTFRI

DORIS will be dropped from ASTRA after RD94 to measure OCPI (Ocean Coupling Potential Index) for typhoon intensity study

∗ Any possibility to have typhoon joint flights among western Pacific countries ?

∗ Joint Program for Western Pacific Typhoon Observation

(JP-WPTO) ?

Questions ?