Transcript Naomi Surgi NCEP/Environmental Modeling Center HWRF Program Leader

Naomi Surgi
HWRF Program Leader
NCEP/Environmental Modeling Center
WHERE AMERICA’S CLIMATE AND WEATHER SERVICES BEGIN
Overview
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HWRF ’07 implementation strategy
HWRF development
Results: HWRF vs. GFDL
HWRF for the future
TRANSITIONING TO HURRICANE WRF
02-03
03-04
05
06
07
Mesoscale Data Assimilation for Hurricane Core
GFDL
Begin Physics
upgrades
Continue
upgrades
Final GFDL
upgrades
HWRF
Begin R&D
Prelim. Testing
grid, hurricane physics
T&E
IOC
THE HURRICANE WRF (HWRF)
PREDICTION SYSTEM
• Community based infrastructure (HWRF began
development 2002)
• Non-hydrostatic hurricane model; movable, nested
grid
• Slated to become operational in 2007; GFDL will run
in parallel
• Coupled air-sea-land prediction system
• Advanced data assimilation for hurricane core (make
use of airborne doppler radar obs and land based
radar)
HWRF continued…..
• Assimilation of ocean observations
• Advanced physics for high resolution and air-sea
• Coupling with wave model (’08)
• Land surface coupled to hydrology/inundation (’09)
• Coupling with dynamic storm surge (>2010)
Hurricane-Wave-Ocean-Surge-Inundation Coupled
Models
NCEP/Environmental Modeling Center
NOS
Atmosphere- Ocean-Wave-Land
land and coastal waters
HWRF SYSTEM
NMM hurricane atmosphere
NOAH LSM
runoff
fluxes
Atmosphere/oceanic
Boundary Layer
winds
air temp.
wave
spectra
radiative
fluxes
High resolution
Coastal, Bay &
Estuarine
hydrodynamic
model
surge
inundation
other fluxes
SST
currents
WAVEWATCH III
Spectral wave model
HYCOM
3D ocean
circulation
model
wave fluxes
elevations
currents
3D salinities
temperatures
Pre-Implementation Strategy for HWRF
FOR THE HWRF OPERATIONAL IMPLEMENTATION:
HWRF MUST PERFORM AT LEAST AS WELL AS
THE GFDL MODEL
 UPGRADE GFDL SYSTEM / Establish GFDL as benchmark
 TRANSITION GFDL UPGRADES TO HWRF
 PERFORM EXTENSIVE COMPARISONS BETWEEN GFDL
AND HWRF FOR MULTIPLE SEASONS AND STORMS
Joint EMC/TPC T&E document now available
Pre-Implementation Strategy for HWRF
Upgrade GFDL as the benchmark for the HWRF
UPGRADE GFDL PHYSICS WITH GFS PHYSICS (’04)
(GFS SAS and PBL schemes)
INCREASE GFDL RESOLUTION (’05)
(inner nest from 18 to 9km.)
IMPLEMENT EMC Ferrier MICROPHYSICS
 UPGRADE AIR-SEA PHYSICS (reduced drag)
 IMPROVE OCEAN INITIALIZATION
‘06
CONTINUED: PRE-IMP HWRF STRATEGY
 TRANSITION GFDL UPGRADES TO HWRF
Next 3-4 weeks:
 HWRF OCEAN COUPLING (ready in 2-3 weeks)
 FINALIZE HWRF PHYSICS (wave dependent drag,
cumulus momentum mixing)
THEN…..(begin in January)
 PERFORM EXTENSIVE COMPARISONS BETWEEN
GFDL AND HWRF FOR THREE SEASONS over ATL and
EPAC
THE Coupled HWRF SYSTEM
2007:
Movable, 2- way nested grid (9km; 27km/42L; ~75X75)
Coupled with ocean (AXBT, altimeter data )
Advanced Physics (atmosphere-waves-ocean)
Advanced vortex initialization (3-D var w/airborne radar
obs to run in parallel)
HWRF Results– 4X daily throughout
’04, ’05, ‘06 hurricane seasons for all
storms – system very stable and reliable
Twenty three HWRF experiments to test
and verify each part of system for clean
comparisons
HYCOM testing/validation
HWRF
DENNIS
HYCOM T&E - Dennis
HURRICANE
EMILY
HWRF
Hurricane
Katrina
HWRF
Hurricane Wilma
Comparisons:
HWRF vs. GFDL
(2006 Version)
HWRF Better than GFDL
(1-5 days)
HWRF Better than GFDL
(1-3 days)
HWRF Comparable than GFDL (1-3 days)
HWRF Comparable or Better than GFDL
(Beyond 72-hrs)
HWRF Worse than GFDL
HWRF Better than GFDL
HWRF Comparable to GFDL
except
HWRF Worse than GFDL
Forecast Spread: Katrina 2005
HWRF
GFDL
Forecast Spread: Wilma 2005
HWRF
GFDL
Forecast Spread: Ernesto 2006
HWRF
GFDL
Forecast Spread: Dennis 2005
HWRF
GFDL
Forecast Spread: Rita 2005
HWRF
GFDL
HWRF better than GFDL
HWRF better than GFDL
PAUL (17E) 2006
ROSA (19E) 2006
Mean Track Errors for East Pac, 2006 (74 cases)
Mean Track Errors for all 11 storms (218 cases)
Next 3-4 weeks:
 HWRF OCEAN COUPLING (ready in 2-3 weeks)
 FINALIZE HWRF PHYSICS (wave drag, cumulus
momentum mixing)
THEN…..(begin in January)
 PERFORM EXTENSIVE COMPARISONS BETWEEN
GFDL AND HWRF FOR MULTIPLE SEASONS AND
STORMS
Aircraft in Hurricanes
Need to develop flight strategies for GIV and P-3’s
Need to obtain resources for flight hrs/add’l crews
New operational requirement for AXBT’s
Two mission profiles:
Environment & core
Observations:
GPS, AXBT’s, Radar
Requirement for operational status of P-3’s
WHAT’s NEXT ????
THE Coupled HWRF SYSTEM
2007:
Movable, 2- way nested grid (9km; 27km/42L; ~75X75)
Coupled with ocean (w/data assimilation for AXBT’s,
altimeter data )
Advanced Physics (atmosphere-waves-ocean)
Advanced vortex initialization (3-D var w/airborne radar)
2012:
 2008
Wave -Coupling
 Coupling
to Wavewatch
III
07: Multi-grid
wave model
(static)
 Land
to streamflow and inundation
08: surface
Movablecoupling
multi-grid
 Development
HWRF
ensembles
09: Waves up of
to the
coastline
(Non-linear
interactions,
 Coupling surf-zone
to dynamic
shallow-water
storm surge model
physics)
(w/NOS)
The multi-grid wave model
Deep ocean model
resolution dictated by
GFS model
Higher coastal model
resolution dictated by
model economy
Highest model
resolution in areas of
special interest
Hurricane nests moving with
storm(s) like GFDL and
HWRF
Advancing HURRICANE WRF System
08
09
10
11
12
Mesoscale Data Assimilation for Hurricane Core
Radial vel. Advance reflectivity
A4DDA
Atm. Model physics and resolution upgrades (continuous)
Atm/ocean boundary layer: wave drag, enthalpy fluxes (sea spray)
Microphysics, radiation
Incr. resolution
(4km/>64L?)
Waves: surf-zone physics
implement
Ocean: 4km. - continuous upgrades in ODAS
 Development of Advanced Probabilistic Guidance
for Intensity/structure (in progress)
HWRF Ensembles
Configuration
initial conditions, resolution, members???
OR
Use of multi model ensembles (MME)
(Share w/Navy?)
(Value of very hi-resolution deterministic forecasts
vs. ensembles?) (LES studies in progress)
HWRF and the community
• Current release HWRF w/movable,
nested grid (2-way)
• Updated physics
• Future version: coupled HWRF system
The Way forward……
Joint strategy/document between NOAA, NRL,
NASA. Available January through OFCM
Science Issues
Fundamental questions (process/sensitivity studies):

Relative role of vortex vs. environment in influencing
intensity.
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Role of ocean. Role of Oceanic heat content.
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Processes within atmosphere-ocean boundary layer on
intensity/structure changes.
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Determinants of structure and relationship with
preexisting wave disturbance. Relationship between
structure and intensity.
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Role of inner core processes for
intensification/weakening, e.g. eyewall replacement
cycles, mixing.
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Relative role of physics, e.g. Air-sea, microphysics,
convection etc. on intensity change in various
environments (sheared vs. non-shear)
Some Model Related Issues
 Data Assimilation
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Assimilation of satellite radiances
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Vortex Initialization
definition of hurricane “core” circulation
where to take obs? difficult for mature storms; more elusive
weaker circulations. (obs taken during RAINEX?)
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Physics
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role of radiation? complexity of microphysics and interaction of
microphysics with radiation
atmosphere/oceanic boundary layer for coupled air-sea-wave
problem. Momentum (wave induced drag) and enthalpy fluxes
(sea spray complexity?)
 Resolution  relative importance of horizontal vs. vertical resolution for
modeling intensity/structure (important consideration for ops)
 Coupled Ocean  advancements to support
 initialization
 vertical mixing
 Obs to support effort data assimilation for improved ocean state
(discussed at 2003 Air-Sea workshop at EMC)
 Land Surface Coupling  Complexity of coupling w/HWRF?
 Sensitivity of LSM for track, structure/intensity, rainfall?
 Future coupling with hydrology/inundation models.
 Validation/Verification/Diagnostics –
initialization
requirement for development of verification techniques
all stages of storm evolution; varying atmos/ocean environment
required obs to support model diagnoistics and verification,
e.g IFEX effort led by HRD
particularly deficient in ocean obs.
temporal and spatial scales?
HWRF TEAM
Gopal S. ; Qingfu Liu; Bob T,
Veejay T. ; Y. Kwon, B. O’Connor
+ Isaac Ginis, Morris Bender……
THANK YOU
FOR YOUR
ATTENTION…
HWRF Cycling System
1. Create a new HWRF domain based on the storm
center position, and fill the outer nest and inner nest
grids with guess data.
2. Run GSI regional analysis for both the outer nest and
the inner nest, then merge the two nested data (we
use a larger domain for inner nest analysis).
3. Run HWRF forecast to obtain 03h, 06h and 09h
forecast fields.
4. Go back to Step 1.
Guess Fields Creation
1. Create a new HWRF domain based on the new
storm center position, interpolate GFS analysis
onto the new HWRF grids (outer nest: 750x750,
inner nest: 60x60)
2. Remove the storm vortex from GFS data
3. Obtain the storm vortex from 6h HWRF forecast
and correct its intensity
4. Insert the modified 6h HWRF vortex back to the
new HWRF grids at the observed position
5. If there are no 6h HWRF forecast, we will skip step
3, and replace the storm vortex with a bogus storm
in step 4.
Ocean initialization and assimilation
• Initial conditions from operational Atlantic forecast model, the
Real Time Ocean Forecast System (RTOFS):
– Data is assimilated during the nowcast cycle of RTOFS
• Boundary conditions are derived from RTOFS:
– Five day forecasts are sampled for volume data twice daily and for the
external velocity and surface elevations three hourly.
• Data Assimilation in RTOFS:
– 2D/3D Var
– Data assimilated includes
• SST
• SSH
• CTD, XBT, AXBT’s….
HWRF atmosphere-ocean coupling
• Sea surface temperature to Atmosphere from:
– Regional ocean (HYCOM) dx~ 8-14(km)
– SST analyses (GFS)
dx~ 30(km)
• Radiative/turbulence fluxes to Ocean from:
– Atmosphere model (HWRF) dx~ 27(km) & 9(km)
• Boundary layer model uses surface wave information
from:
– Wave model (Wavewatch 3) dx~ 30(km)