Ocean observations in developing and mature TC

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Ocean observations in developing and mature TCs
based on a new airborne observing strategy
'Combo' deployments of AXBTs and GPS
dropsondes from long-endurance, multi-altitude
reconnaissance flights
P. G. Black1 and J. D. Hawkins2 1SAIC, Inc./Naval
Research Laboratory, Monterey, CA 2Naval
Research Laboratory, Monterey, CA
Collaborators E. DAsaro M. Ohmart- U.
Washington P. Harr, A. Penny, C. DePalma, R.
Creasey and H. Hornick- NPS Y. Jin, S. Chen, J.
Cummings, S. Wang, J. Solbrig M. Surrat- NRL
G. Elliott G. Foley- BoM-Au M. Kucas, R.
Ballucanag, K. Bench C. Morris- JTWC P.
Niiler- Scripps J. Kerling- NAVO Robert Lee-
CORLEE, Lld. LtCol Roy Deatherage, 53rd WRS-AFRC
65th Interdepartmental Hurricane Conference
(IHC) 28 February 3 March, 2011 Miami, Florida
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• Objectives
• Observe atmosphere and ocean during formation
  phase of candidate TCs
• Observe TC Inner-Core surface wind field and
  ocean structure, especially during RI/RD.
• Observe mature phase cold wake formation,
  structure and time evolution.
• Technical Approach
• Design and execute WC-130J aircraft flight plans
  for optimal achievement of ITOP goals.
• Employ two WC-130J aircraft/crews with SFMR, AXBT
  and buoy-deployment capability- transmit data in
  real-time.
• Conduct joint flights of 53rd WRS WC-130J and
  DOTSTAR ASTRA.

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• ITOP Operations
• Aircraft Module
• Synoptic surveillance module (Taiwan-NTU/ CWB)
• Taiwan moorings (4)
• U. Miami ASIS/EASI moorings (2)
• Satellite image acquisition (NRL)
• SAR image acquisition (U. Miami)
• R/V Revelle 4 Taiwan research vessels
• Ship-based AUVs (16)

ITOP DOTSTAR/WC-130J joint observations Fanapi
(2010)
WC-130J
DOTSTAR- ASTRA
0000 UTC, Sept. 17th
0000 UTC, Sept. 18th
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WC-130J Ocean Sensor Deployments
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MOOS
Drifters - Floats
NRL Mobile Ocean Observing System
AXBT/Launcher
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Fanapi
Malakas
Megi
ITOP TC tracks and ARGO ocean temperature
profiles near point of development showing range
of D26 values (Courtesy I-I Lin)
CAT 3
TY Fanapi (70m)
CAT 2
TY Malakas (40 m)
CAT5
STY Megi (120m)
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Semi-Diurnal Tide in the Philippine Sea
Model Ko
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Fanapi development modulated by ocean features!
TC Fanapi
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1) Slow development over Warm pool-cold eddy
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TC Fanapi
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2) Formation over WARM EDDY
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Fanapi 13 Sept Warm/Cold Eddy
ITOP AXBT Data
60 m variation in 26oC isotherm
100 m variation in 26oC isotherm
Semi-Diurnal Tides
50 m variation in 26oC isotherm over 9 hr
Fanapi 14 Sept Warm Eddy
Eddy ocean structure variability greater than
that from diurnal tides!
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1.Wave growth over deep D26
5.FANAPI genesis over warm eddy
3.Sfc vortex develops over warm/cold eddies
2.Weak wave vertical consistency
4.Slow vertical development
6.Vertical development established
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OHC26 KO EASNF 19 Sept Typhoon Fanapi region
Major Eddy Locations
Cold
Warm
A1, A2, A3 moorings
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AMSR-E Fanapi Cold Wake Monitoring Typhoon Phase
NTU Lin
NRL Hawkins
Eddies modulate cold wake
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Similar to TCS08 STY Jangmi RI/RD episode
Jangmi Rapid Intensification/Decay Coincides with
passage over warm/cold eddy pair prior to Taiwan
landfall ITOP/TCS10 STY Megi undergoes RI over
large D26 and OHC26 region
RD
RI
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Jangmi TCS08 COAMPS-TC Coupled and Uncoupled
Intensity Simulation
Eddy
Landfall
(Courtesy Y. Jin)

• Coupled COAMPS-TC continued RI until cold eddy
  passage and began weakening following passage,
  prior to landfall.

• Uncoupled COAMPS-TC began weakening only after
  landfall.

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Key Results

• TC formation process modulated by underlying
  ocean heat content structure
• TC Rapid Intensification/Rapid Decay (RI/RD)
  cycle strongly modulated by
• underlying ocean eddy pairs
• Warm and cold eddies modulate cold wake
• Warm and cold eddy pairs contribute to timing
  of RI/RD

Future Plans

• Develop additional diagnostic analysis tools
  for TPARC/TCS08 and ITOP/TCS10 aircraft data and
  companion COAMPS-TC model output fields.
• Develop operational AXBT/Sonde Combo TC data
  archive to assist in initializing and validating
  coupled TC prediction models