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 University
2Chinese Culture University
OUTLINE
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
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/G4
Atlantic 2002
• TD EDOURAD
• TD FAY
Phase 1 : 2003-2005
Funding 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 days
Storm Watch (CWB, NTU)
DB 3~2 days
Flight path making (NTU)
Flight plan sending to NAHA, Philippines, HK FIR (AIDC)
DB: Day Before
DA: Day After
DB 2~1 days
Crews Call (NTU)
Decision making (Go or not) (NTU+CWB)
DB 5~2 hrs
Ground transportation Taipei---Taichung (NTU)
DB 2~1 hrs
Final ground check (AIDC + NTU)
DB 1hr
Mission + Weather briefing (AIDC + NTU)
DA 0~6hrs
Drop + onboard code editing + voice communication (NTU, AIDC, CWB)
ASTRA (Gulfstream 100)
RD94 dropsonde
AVAPS operator
System Engineer
Code editor
Launcher + PI (visitor)
pilots
gate
Satcomm
Code
editor
SE
internet
launcher
AVAPS
operator
PI / Visitor
toilet
Onboard data processing
Astra Jet flight Information
RD94 dropsonde in-air data
Pilot console
AR-429 Bus-Card
AVAPS
(Airborne Vertical Atmospheric Profiling System )
Vaisala
Madonna (2003-2006)
(realtime airborne and dropsonde
data ploting & diagnosis system )
ASPEN
(Atmospheric Sounding Processing Environment )
NCAR
Britney (2007~)
(Bright tool for onboard enjoy)
NTU
DCF
NTU
(Data Compress and FTP sending )
Satcomm
FTP
TTFRI
CWB
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: 64
TY : 49
Dropsonde impact study by NCEP GFS
2003-2009 45 TCs (35 cases)
Improvement of track
error 12~18%
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 CWB-TWRF
2008-2012 22 TCs (34 cases)
Improvement of track error ~8%
track errors (km)
300
250
TWRF_45_DP
200
TWRF_45_NODP
244
177
151
150
114
87
100
50
67
13
55
0 (34)
12 (34)
13
221
167
140
115
82
0
24 (34)
36 (32)
48 (30)
60 (28)
72 (24)
forecast hours (case no.)
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 )
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
Target observation
> 500 km
/ 216
for sensitivity regions
Characteristics of Typhoon Outer Core
Tangential velocity
DR
DL
UR
UL
1100m
DL: shallow and small
DR: deep and larger
UR: maxi wind at ~1100m height and 1.4 times more than DL
Characteristics of Typhoon Outer Core
Tangential velocity (UR)
DR
DL
UL
UR
Typhoon intensity defined by CWB
1100m
light : strong (1 : 1.4 )
DR
UR
In-situ measurement of wind speed
by Aerosonde in Typhoon Longwang 2005
(Lin and Lee, 2008)
DL
UL
Characteristics of Typhoon Outer Core
Relative Humidity
DR
DL
UR
UL
600m
Compared with wind field, moisture profiles are more symmetric in outer core of typhoon
DR
DL
Characteristics of Typhoon Outer Core
Relative Humidity (UR)
UR
UL
500m
light : strong (1 : 1.03 )
DR
DL
UR
Characteristics of Typhoon Outer Core
Virtual Potential Temperature
UL
500m
Compared with wind field, thermal profiles are more symmetric in outer core of typhoon
Unstable level height is about ~ 500m height
DR
DL
Characteristics of Typhoon Outer Core
Virtual Potential Temperature (UR)
UR
UL
500m
Stability below 500m in different intensity of typhoon needs more study
eye crossing flights and Inner core of typhoon
*2003 Melor
N
S
N
S
N
S
Comparison of vertical profiles between Inner core and outer core
lower and stronger windshear + more humid
Summary and next step
• 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
DR
UR
DL
UL
Summary and next step
DORIS:
A mini AXBT(airborne XBT) in same size of RD94 dropsonde
is 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
Questions ?
∗ Any possibility to have typhoon joint flights among
western Pacific countries ?
∗ Joint Program for Western Pacific Typhoon Observation
(JP-WPTO) ?