Overview of WC-130J storm-scale
observations during TPARC/TCS08
Peter G. Black (1) and Jeffrey D. Hawkins (2)
(1) SAIC, Inc. and Naval Research Laboratory, Monterey, CA
(2) Naval Research Laboratory, Monterey, CA
Third THORPEX International Science Symposium
Monterey, CA
14-18 September, 2009
TCS08 Experiment Analysis: Tools
What did we use?
1) WC-130J Aircraft (2)
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GPS dropsonde (750, ~ 26/flt) for
atmospheric profiling (high-altitude)
AXBT*- ocean thermal profiling (250, ~ 13/flt)
SFMR- surface winds
Radar Video Recording*- TC structure
ADOS profiler/ Minimet drift buoys- 3D ocean
structure, surface currents (24)
2) NRL P3 (1)
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Eldora Doppler Radar- 3D winds
LIDAR*- boundary layer wind profiles
GPS dropsonde- atmospheric profiling (low)
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*First used in TCS08
TCS08 Experimental Analysis: Statistics
WC-130J Aircraft Performance
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Research Flights
Missions: 26
Mission Flight Hours: 263
High-Level Missions, 300mb: 12
TC 700mb Missions: 12
Buoy Deployment Missions: 2
Tropical Cyclones: 4
TC Observational Strategy
• Define vertical structure over a TC
vortex-scale domain (WC-130J) in
developing/intensifying systems within
environmental domain (SAT, DOTSTAR,
FALCON) to provide context for
mesovortex (VHT) domain (P3)
• Focus on better definition of asymmetric
3D initial vortex in sheared environment
for evolving coupled models
• Driven by emerging requirements for
improved 5 to 7 day forecasts
Unprecidented Real-Time
Satellite Capabilities: Data Fusion
TCS08 Experiment Analysis:
Situational Awareness
Real-Time Data Fusion
Real-Time Communications
TCS08 Experiment Analysis: HYPOTHESES I
First of Two Key Hypotheses:
I.
Typhoon Formation emerges from initial
meso-vortex in Convective Cloud Clusters via:
•
Mid-level spin-up and downward growth, i.e.-
Top-Down
OR
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Low-level spin-up and upward growth, i.e.-
Bottom-Up
TCS08 Experiment Analysis: Scenarios
Two of several
Key Formation Scenarios:
•
Tropical Easterly Wave/ Upper Trough
Interactions: (Many observed during TCS08)
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Westerly Wind Burst associated with
monsoon trough: (NONE observed during TCS08)
TCS08 Experiment Analysis: RATIONALE I
Why Investigate TC Formation?
I.
New 5-day forecasts (soon 7-day forecasts)
require improved knowledge of TC Formation:
•
•
Where?
How Fast?
II. Strategic and economic consequences
increasing exponentially with time!
TCS08 Experiment Analysis: OBJECTIVE I
1) Address Hypothesis I: Develop
high-level WC-130J Aircraft observing
strategy to define:
• TC 3D storm-scale structure
• Intensity Change
• Context for NRL P3 meso-scale obs
TCS08 Experiment Analysis: RESULTS I
(Preliminary)
1)
Hypothesis I: Concurrent low- and mid-level
vortices were observed in developing and
non-developing TC Formation cases
with 120 – 200 km separation (In Tropical
Wave/ TUTT interaction cases), i.e. not single
tilted vortex, but distinct vortex pairs
Challenge is to learn to distinguish
developers from non-developers
TCS-25
27-28, Aug
Surface
TCS-25
27-28, Aug
700 mb
Surface
120 km
700 mb
15 kt
20 kt
x
x
15 kt
20 kt
SSMIS- F16
27 Sept, 2213 GMT
WC-130J sondes- SFC
27 Sept, 21 UTC 28 Sept, 03 UTC
x
TCS-37
Surface
15 kt
15 kt
200 km separation
TCS-37
400 MB
25 kt
25 kt
Active convection
At begining of flight
Data Fusion:
Google-Earth
Enhanced IR +
WC-130J flight track,
Dropsonde locations
0330 UTC
7 Sept, 2008
TCS-37
0030 UTC
7 Sept, 2008
Convection collapses
near end of flight
TCS08 Experiment Analysis: HYPOTHESES II
Second of Two Key Hypotheses:
II. Typhoon Intensity Change, including Rapid
Intensification (RI), is driven by atmospheric
conditioning:
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Large-scale environmental interaction
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Oceanic Variability
TCS08 Experiment Analysis: RATIONALE II
Why Investigate
TC Rapid Intensity (RI) Change?
I.
Rapid Intensity (RI) Change accounts
for more than half of the large TC intensity
forecast errors.
II. Strategic and economic consequences
for unforecasted RI, which occur in only
15% of the TC life cycle, account for 85%
of TC losses.
TCS08 Experiment Analysis: OBJECTIVE II
2) Address Hypothesis II: Develop TC
and ocean observing strategy to define
background ocean conditions and
ocean-TC interaction
(Environmental monitoring accomplished by TPARC
large-scale observing strategy)
TCS08 Experiment Analysis: RESULTS II
(Preliminary)
2) Hypothesis II: Rapid TC Intensification
and Rapid TC Filling occurred over Warm
and Cold eddies, respectively, in the WPAC
Southern Eddy Zone*
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Defined by Wu, et al. (18-25N)
TCS08
Jangmi Sept, 2008
Track,
Intensity Change
1000
Landfall
960
Rapid
Filling
940
50
920
Rapid Structure Change
900
0
9/23
9/24
9/25
9/26
9/27
9/28
9/29
9/30
10/1
10/2
Pressure (mb)
980
Kuroshio
100
Wind Speed (kt)
150
OHC Gradient
Aircraft Pmin
Aircraft
JMA
SATCON Intensity:
Velden, CIMSS
Hawkins, NRL
Rapid Structure Change
SSTA
27 Sept, 2132
STY Jangmi
27 Sept, 1134
Warm, Deep
OHC Gradient
Cold,
Shallow
28 Sept, 0006
27 Sept, 0445
Jangmi
SSTA
2008
26 Aug
Jangmi
OHC
27 Aug
Jangmi
SSTA
2008
28 Aug
QSCAT- and ASCAT-only
Data over-estimates size
And under-estimates
intensity
WC-130J
SFMR data defines true
TC intensity and size
Radar Video defines
Eyewall and Rainband
Structure and Evolution
Super-Typhoon
Jangmi
27 Sept., 2008
0935 UTC
Aircraft – Buoy Deployment
First occurrence of the deployment
of drifting buoys ahead of a category
5 tropical cyclone (Jangmi). Chart at
left and imagery below are from a
few hours after the deployment of
the buoys along the diagonal to the
northwest of the TC
2313 UTC 26 September
First buoy
deployment
In TY Hagupit
several days
earlier
P-3 flight track
Second deployment
in STY Jangmi
Buoy, aircraft, and satellite data in Google Earth
TCS08 Ocean Heat
Content Obs:
•Concurrent with GPS
dropsondes
•Preview of ITOP2010
AXBT vs NRL Ocean
Model Initial Conditions
Ocean Heat
Content (OHC)
TCS08 AXBT Locations
Ko, NRL Stennis
Model
underpredicts
high heat
content
Data Gap
Data Gap
AXBT’s act to fill data
gaps in drifter coverage
And define spacial gradients
2008 Drifters
25 Aug
27 Aug
29 Aug
D26
AXBT’s help to adjust model-predicted
eddy locations
Ko, NRL Stennis
FINAL COMMENT
• We are at an historic turning point in history
for improving hurricane intensity observation
and forecasting where the capability to
observe the TC surface and mid-level wind
domain concurrent with subsurface ocean
thermal structure matches the improved
coupled model capabilities to assimilate and
model the total TC environment.
• This alignment should provide the next best
opportunity for improving hurricane intensity
and structure forecasting.
CONCLUSIONS
1.
‘Tip-of-the-iceberg’ Results:
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2.
‘Stage is set’ for additional in-depth analysis
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3.
Co-existence of low/mid level vortex pairs is typical of formation events
Strong relation of RI/RF to warm/cold ocean eddies in absence of strong
atmospheric forcing
The observation strategy for TCS08 was sound
Determine system evolution with time
Validate satellite estimation schemes
Elaborate theoretical hypotheses leading to new physics
Conduct coupled numerical model simulations to test new physics
For the Future- Fill GAPS (possibly in concert with ITOP 2010) by observing:
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Normally-dominant monsoon trough/ westerly burst formation events
Vortex-pair TC formation scenarios
Satellite validation cases to reach statistical significance
Air-sea RI events with and without strong shear for small/large TCs
END
Overview of WC-130J storm-scale
observations during TPARC/TCS08
AUXILLARY SLIDES
Peter G. Black (1) and Jeffrey D. Hawkins (2)
(1) SAIC, Inc. and Naval Research Laboratory, Monterey, CA
(2) Naval Research Laboratory, Monterey, CA
Third THORPEX International Science Symposium
Monterey, CA
14-18 September, 2009
TCS08 Experiment Analysis: Milestones
What did we do?
1. Developed detailed flight plan and communications
strategies
2. Developed and implemented AXBT observing system
and implemented drift buoy deployments
3. Implemented high altitude (300 mb) TC formation flight
strategy with concurrent GPS sonde and AXBT
deployments over a 5 deg grid
4. Provided maximum surface wind and minimum surface
pressure observations during TC life cycle for validation
of satellite TC Intensity estimates (Hawkins, et al)
5. Provided aircraft SFMR, radar video, AXBT and GPS
dropsonde data for initialization/validation of COAMPSTC coupled model simulations of STYJangmi and other
TCS08 typhoons (Doyle, et al)
TCS08 Flight Patterns: Formation
Base of Operations
Define multi-level
vortex and cloud
cluster evolution
Zig-Zag
Square Spiral
Racetrack
Bow-Tie
TCS08 Flight Patterns: TC Structure
Base of Operations
Define mean vortex
Observe Pmin, Vmax
Rotated Fig 4
Butterfly
Bow-Tie
Figure 4
Define structure, TC asymmetries