BMRCCAWCR RESEARCH INTEREST IN

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BMRC/CAWCR RESEARCH INTEREST IN T-PARC
TCS08 Noel Davidson, Chi Mai Nguyen2,3, Yimin
Ma, Harry Weber1, Kevin Tory, and Jeff
Kepert BMRC/CAWCR, Melbourne,
Australia 1Meteorological Institute, University
of Munich 2National HydroMeteorological Service,
Hanoi, VietNam 3School of Mathematical Sciences,
Monash University, Victoria US Office of
Naval Research mtm, mjr
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• Dare and Davidson, 2004 Tropical Cyclone
  Characteristics in the Australian Region. Mon.
  Wea. Rev.
• Forecast issues
• Track,
• Genesis,
• Intensification/Decay,
• ET (and TT),
• Landfall the ultimate challenge

Data for Diagnosis, Initialization and Validation
nearly NON-EXISTENT in the Aust. Reg.!! Cannot do
diagnosis, validate structures or quantify
forecast skill much beyond track. So, validate
over the US.. and NW PACIFIC during T-PARC
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CURRENT, ONGOING AND FUTURE PROJECTS Research
Interest in T-PARC and TCS08

• Operational Prediction of TC behavior with
  TC-LAPS ( successors).
• Genesis Diagnosis and Prediction, Tory et al.,
  JAS, 2006 a,b, 2007,etc
• Environmental Influences on Rapid
  Intensification.
  
• Ensemble Simulations from High-Resolution TCLAPS
  
• Intensity and Track Sensitivity, Vortex Structure
  Evolution.
• Vortex Structure Change during Rapid
  Intensification.
• Initialization for Prediction of Hurricane Track
  and Structure.
• Observed and Synthetic Vortex Structures
• Sensitivity of Track, Structure and Intensity to
  Initial Vortex Structure.
• Monitoring and Prediction of the Monsoon and MJO
  over the NWPac
• 2008 Tropical and Extratropical Transition in
  the Aust. Region.

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2007 OPERATIONAL PREDICTION WITH TC-LAPS
Sepat Man-Yi Lekima Sidr
Some skill at intensity prediction but
performance is inconsistent .... Source of the
Inconsistency LSE, Vortex Structure, SST/
Surface Interaction (Fluxes)
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TC-LAPS - OPERATIONAL FROM 1999 Davidson and
Weber, 2000, MWR
TC-LAPS has five basic components all are
critical Data assimilation (Bourke, Steinle,
Kepert, Tingwell, ) to establish the storms
large-scale environment (LSE) and outer
structure. (0.3750X29L,550S-550N, 700E-1800E)
Vortex specification (Weber and Davidson
Holland vortex) to construct the inner core
circulation and motion asymmetries consistent
with the estimated size, intensity and past
motion, and then to re-locate the circulation to
its observed position. High-resolution (HR)
analysis (Steinle, Mills, Davidson) with
appropriate observational errors, length scales
and quality control tolerances, to merge the
intense vortex into the LSE. (0.150X29L,
270Lat-Long) Initialisation with diabatic,
dynamical nudging, (Davidson and Puri) to balance
the vortex using the models dynamics, and to
re-define the vertical motion field to be
consistent with the satellite imagery.
High-resolution prediction (Puri et al., 1998)
with the generalised LAPS forecast model, which
contains high order numerics and sophisticated
physical parameterisations.
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During T-PARC/TCS08 will run An Operational
(0.15) and a Research (0.05) Configuration (30x30
degs lat-lon) of TC-LAPS with mesoscale DA for
Genesis and Named-Storms
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ENVIRONMENTAL INFLUENCES ON RAPID INTENSIFICATION
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ENS experiments with High Resolution
TCLAPSKatrina (2005)
1. Perturbed observations (C) 2. Nudging methods
(N) gt Small change in track and intensity
3. Boundary conditions (E) gt Large variations
in track, and hence, intensity due to different
SST along the tracks gt 80 of variations in
intensity can be explained by variations in SST
4. Model and vortex configurations (P) gt
Large change in track and intensity a. Larger/sma
ller vortex deflect to the left(south)/right(north
) of the control track b. Larger/smaller vortex
intensified slower/faster and reached a higher
/lower intensity c. Change in SST gt change in
intensity structure gt change track d.
Inclusion of both convective parameterization and
bulk microphysics results in a smaller intensity
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DIFFERENT B.C
MODEL VORTEX CONFIG.
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KATRINA (2005) FORECASTSIntensity and Vortex
structure evolution
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KATRINA (2005) FORECASTS Vertical velocity at
850hPa
Symmetric phase Faster intensification rate (at
39h)
Less symmetric phase Slower intensification
rate (at 44h)
Wave No. 4 structure
Wave No. 3 structure
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KATRINA (2005) FORECASTS (Strain Enstrophy)
at 500hPa
Symmetric phase Faster intensification rate (at
39h)
Less symmetric phase Slower intensification
rate (at 44h)
Weaker strain
Stronger strain
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KATRINA (2005) FORECASTS Barotropic
instability dPV/dr at 850hPa
Symmetric phase Faster intensification rate (at
39h)
Less symmetric phase Slower intensification
rate (at 44h)
Large region of positive dPV/dr
Small region of positive dPV/dr
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7 NORMALIZED WIND PROFILES (Mean of 152 Structure
Estimates from QC EXBT DS of DeMaria et al.)
What aspects of Vortex Structure are important
for prediction?
VMAX, CP, RMW, (R64, R50), R34, ROCI
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7 WIND PROFILES FOR SPECIFIC TCs
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KATRINA 2005 Evolution of symmetric 975 hPa wind
profiles
EF Enhanced Fujita H80 Holland (80) ACW
Amended ChanWilliams (87) TCH TCLAPS
operational F52 Fujita (54) EH Enhanced
Holland TCF TCLAPS Fujita
F48h
F00h
Slow Decrease in winds beyond the RMW
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TC GENESIS PROJECT..ongoing Tory et al.,
2006a,b, 2007 JAS
In the absence of other inhibiting
factors (eg, strong wind shear, cold SSTs), TC
genesis occurs via a concentration of
environmental cyclonic absolute vorticity driven
by deep convection.. Both sufficient
active deep convection (net-upward mass flux
Mu(CE)) and a sufficiently cyclonic environment
are necessary for formation (Tory, circa 2007)
00h
48h
850 hPa wind field from valid time 00z,
20OCT2006.
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REAL-TIME MONITORING AND PROJECTIONS OF THE
MJO Wheeler and Hendon
http//www.bom.gov.au/bmrc/clfor/cfstaff/matw/mapr
oom/index.htm
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POSSIBLE IMPLICATIONS FOR T-PARC
TCS08 (Selfish, Wish-List!!)

• Obs and DA Methods to define
• Pre-conditioning of Tropical Atmosphere during
  Extratropical Tropical Interaction and/or
  arrival of MJO (Moisture, Omega in Monsoon
  Trough).
• Downstream Development Events at Upper Levels.
  (nd)
• Moisture Distribution through the Entire Depth of
  the Troposphere over Regions of Disturbed
  Weather. (kt)
• Dynamical Regimes (evolving in Space and Time)
  within Typhoons. (cmn)
• Both the Rotational and Divergent Flows, to
  scales of approximately 500km for the LSE, and to
  20km inside r 200 km for Typhoons!! (yma)

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SUMMARY OF RESEARCH INTERESTS

• Real-time Prediction and Diagnosis of Genesis
• Vortex Structure Observed vs Synthetic
• Operational Prediction of Track, Structure and
  Intensity
• Environmental Influences on Storm Behaviour
  
• Downstream Development
• Phase and Group Propagation at Upper Levels
• Real-time Monitoring and Predictions of the
  Monsoon and the MJO

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The Rest are Spares!!
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FORMATION OF TY SEPAT (850hpa Wind) 00UTC,
20070813, near 16.9N, 135.5E, 996hpa
00h
48h
COLD START
NO CTT HEATING
MTSAT-CTT HEATING
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• Environmental Influences
• Evolving Midlatitude Circulation.
• Downstream Development.
• Cg gtgt 0, Cp 0 (separation).
• Long, Large Amplitude Waves in the presence of a
  Jet.

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BAROTROPIC DYNAMICS Cp, Cg vs Umean, for
various Lx, Ly, and ß ß - d2U/dy2 Long,
Large-Amplitude Waves with a Jet Structure
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Vorticity conservation theory advanced
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Changing state of gradient wind balance

• Eliassen balanced vortex Response to a point
  heat source in a rotating environment.

LR
The scale of the response (LR) is proportional to
the magnitude of the system rotation. The
response enhances the system rotation. Persisten
t convection thus results in a contraction in
scale and concentration of spin-up energy.
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Changing state of gradient wind balance

• Eliassen balanced vortex Response to a point
  heat source in a rotating environment.

LR
The spin-up efficiency increases the more the
system spins up.
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Thermodynamic considerations

• System spin-up proportional to net-upward mass
  flux (Mu) and environmental absolute vorticity
  (?a)

Rs surface rainfall C condensation E
evaporation

• System spin-up efficiency (Sef) proportional to
  Mu / released energy
• Released energy proportional to total
  condensation.

• Dry environment ? evaporation of cloud water and
  precipitation
• Spin-up efficiency increases with environmental
  humidity