Chuck Skupniewicz

1
Fleet Numerical Meteorology Oceanography
Center TCC 29-30 April 2009
GFDN 2009
Chuck Skupniewicz Models (N34M) FNMOC
Operations Dept
The GFDN Team Carey Dickerman, FNMOC lead Roger
Stocker, FNMOC Isaac Ginnis, URI Morris Bender,
GFDL
Fleet Numerical
Supercomputing Excellence for Fleet Safety and
Warfighter Decision Superiority
2
Old vs New GFDN Comparison of Main Features
GFDN GF3C
Ocean Coupling none POM (3-D)
Nests ½, 1/6 1/2, 1/6, 1/12
Grid domain 75 X 75, 11 X 11 Fixed moving 75 X 75, 11X 11, 5 X 5 Fixed moving moving
Dissipative Heating none Added to Core Region
Microphysics Large-scale Condensation NCEP Ferrier Upgrade
3
Ocean response to hurricane forcing 1. Vertical
mixing/entrainment
A T M O S P H E R E
Wind stress ? surface layer currents
Current shear ? turbulence
Turbulent mixing ? entrainment of cooler water
O C E A N
Warm sea surface temperature
Sea surface temperature decreases
Cool subsurface temperature
Subsurface temperature increases
This is a 1-D (vertical) process
from Ginnis et al., Developing Coupled Tropical
Cyclone-Wave-Ocean Models for Transition to
Operations, 63th Interdepartmental Hurricane
Conference, St. Petersburg, FL, 2009.
4
Ocean response to hurricane forcing 2. Upwelling
A T M O S P H E R E
Cyclonic wind stress ? divergent surface currents
Divergent currents ? upwelling
Upwelling ? cooler water brought to surface
O C E A N
Warm sea surface temperature
Cool subsurface temperature
This is a 3-D process
from Ginnis et al., Developing Coupled Tropical
Cyclone-Wave-Ocean Models for Transition to
Operations, 63th Interdepartmental Hurricane
Conference, St. Petersburg, FL, 2009.
5
SST cooling within hurricane inner-core in 3D and
1D ocean models
Hurricanes have historically translated in the
Gulf of Mexico lt 5 m s-1 73 and lt 2 m s-1 16
of the time in the western tropical North
Atlantic at lt 5 m s-1 62 and lt 2 m s-1 12 of
the time
from Ginnis et al., Developing Coupled Tropical
Cyclone-Wave-Ocean Models for Transition to
Operations, 63th Interdepartmental Hurricane
Conference, St. Petersburg, FL, 2009.
6
Typhoon Cimaron November 2nd , 0000 UTC, 2006
Demonstrates Importance of Upwelling for Slow
Moving Storm
1-D Coupling
3-D Coupling
HOUR 0
HOUR 0
1-D Coupling
3-D Coupling
HOUR 120
HOUR 120
7
Significantly Improved Prediction of Track and
Intensity( Typhoon Cimaron November 2nd , 0000
UTC, 2006)
MAXIMUM WINDS
3-D Coupling
CENTRAL PRESSURE
1 3-D OCEAN COUPLING 2 2006 OPERATIONAL
GFDN 3 1-D OCEAN COUPLING
3-D Coupling
8
GFDN Forecast Performance Intensity Forecast
Validation against Old
Northern Indian Ocean - io012008 North Atlantic
- al022008 North Eastern Pacific - ep022008,
ep052008 Southern Hemisphere - sh232008,
sh262008, sh282008 Northwestern Pacific -
wp042005, wp212005, wp042006, wp112006, wp212006,
wp222006, wp052007, wp072007, wp072008
9
GFDN Forecast Performance Statistical Typhoon
Intensity Prediction Scheme (ST5D) Validation
Northern Indian Ocean - io012008 North Atlantic
- al022008 North Eastern Pacific - ep022008,
ep052008 Southern Hemisphere - sh232008,
sh262008, sh282008 Northwestern Pacific -
wp042005, wp212005, wp042006, wp112006, wp212006,
wp222006, wp052007, wp072007, wp072008
10
GFDN Forecast Performance Tracks
TRACK ERROR (NM)
Northern Indian Ocean - io012008 North Atlantic
- al022008 North Eastern Pacific - ep022008,
ep052008 Southern Hemisphere - sh232008,
sh262008, sh282008 Northwestern Pacific -
wp042005, wp212005, wp042006, wp112006, wp212006,
wp222006, wp052007, wp072007, wp072008
11
IMPROVED TRACK AND INTENSITY SKILL AT ALL TIME
LEVELS FOR SELECTED WPAC CASES (2005-2007)
AVERAGE TRACK SKILL
AVERAGE INTENSITY SKILL
from Bender et al., Upgrades to the GFDN model
for 2009 and Beyond, 63th Interdepartmental
Hurricane Conference, St. Petersburg, FL, 2009.
12
GFDN STATUS - TODAY

• Operational on A2 since Oct 2008.
• Atlantic 3-D Princeton Ocean Model (POM)
  forecast with GDEM ocean climatology
  initialization. NOGAPS (NCODA low resolution)
  SST analysis.
• Pacific 1-D POM with 3-D NCODA analysis
  initialization. NCODA high resolution SST
  analysis.

13
GFDN STATUS June 2009

• Adding Asymmetry Factor. DONE. Operational in
  January.
• Adding altimetry data assimilation for Atlantic
  to define Gulf of Mexico Loop Current. DONE
  Operational in April.
• With University of Rhode Island, adding POM-3D in
  the Pacific. Delivery in March. Operational in
  May.

14
OVERALL REDUCED INTENSITY ERRORS WITH 3-D
COUPLING COMPARED TO 1-D
1-D GFDN
1-D GFDN
3-D GFDN
3-D GFDN
from Bender et al., Upgrades to the GFDN model
for 2009 and Beyond, 63th Interdepartmental
Hurricane Conference, St. Petersburg, FL, 2009.
15
REDUCED TRACK ERRORS IN DAYS 4 AND 5WITH 3-D
COUPLING
OLD GFDN
from Bender et al., Upgrades to the GFDN model
for 2009 and Beyond, 63th Interdepartmental
Hurricane Conference, St. Petersburg, FL, 2009.
16
ISSUES

• Joint JTWC / FNOC review of SOPs (in progress)
• Need an independent review of GFDN upgrades by
  JTWC.
• Need to watch GFDL vs GFDN (GFS vs NOGAPS)
• NOAA has stopped funding for GFDL. FNMOC relies
  on GFDL/URI developers for maintenance.

17
2008 Northern Hemisphere Homogeneous TC Forecast
Error (nm) 01 August 2008 17 September 2008
150
116
86
Number of Forecasts
68
50
18
GFDN DONE BACKUP SLIDES FOLLOW
19
Atmospheric Boundary Layer
Heat Humidity Flux
Momentum KE Flux
Turbulence
Sea Spray
Wave induced stress? Reynolds stress ?
Airflow separation Intermittency
Air-Sea Interface
Nonbreaking Waves
Breaking Waves
Stokes drift
Bubbles
Momentum KE Flux
Intermittency of Momentum KE injection
MORE PHYSICS TO COME
(Langmuir) Turbulence
Ocean Boundary Layer
from Ginnis et al., Developing Coupled Tropical
Cyclone-Wave-Ocean Models for Transition to
Operations, 63th Interdepartmental Hurricane
Conference, St. Petersburg, FL, 2009.
20
2008 Atlantic Non-Homogeneous TC Forecast Error
(nm)
Interpolated Model Guidance AVNI Global
Forecast System (GFS) run at NCEP GFDI GFDL
model run at NCEP HWFI Hurricane WRF run at
NCEP NGPI Navy global model (NOGAPS) run at
FNMOC GFNI GFDL model run at FNMOC EGRI UK
Met Office global model EMXI ECMWF global
model TVCN Consensus of above models (at least
two) AEMI NCEP GFS ensemble mean
251
160
314
204
131
Number of Forecasts
from Goerss, J., Ensemble, Corrected Consensus,
and Weighted Consensus TC Track Forecasts, 63th
Interdepartmental Hurricane Conference, St.
Petersburg, FL, 2009.
21
2008 Eastern North Pacific Non-Homogeneous TC
Forecast Error (nm)
238
178
130
90
57
Number of Forecasts
from Goerss, J., Ensemble, Corrected Consensus,
and Weighted Consensus TC Track Forecasts, 63th
Interdepartmental Hurricane Conference, St.
Petersburg, FL, 2009.
22
NCEP COMPARISON Apples to Oranges

• The following is from storm AL172008, which
  was an early November 2008 TC. It's the one AL
  storm with some history that was forecast by the
  OPAL OPS GFDN.
• FORECAST VERIFICATION RESULTS
• AVERAGE TRACK ERRORS (NM) FOR HOMOGENEOUS SAMPLE
• 00 12 24 36 48
  72 96 120
• GFDN 6.4 34.0 63.1 96.2 119.1
  167.1 147.1 0.0
• GFDL 6.0 43.8 63.5 74.4 82.5
  111.6 262.5 0.0
• CASES 14 14 12 10 8
  4 1 0

• AVERAGE INTENSITY ERRORS (KT) FOR HOMOGENEOUS
  SAMPLE
• 00 12 24 36
  48 72 96 120
• GFDN 12.7 18.8 25.6 33.5 37.9
  16.0 27.0 0.0
• GFDL 9.2 20.6 18.3 14.8 14.4
  26.0 39.0 0.0
• NCHG 0.0 24.6 43.3 51.5 53.1
  40.0 5.0 0.0
• CASES 14 14 12 10 8
  4 1 0

23
2008 Western PacificHomogeneous TC Forecast
Error (nm)
(UKMet)
24
JTWC TRACK ERRORS (WESTPAC - 96-120 Hours)

• 96 Hr 120 Hr
• 2004 206 275
• 2005 212 263
• 2006 216 309
• 187 214
• 301 447
• Goal 200 250

from Falvey et al., JTWC 2008 Report, 63th
Interdepartmental Hurricane Conference, St.
Petersburg, FL, 2009.
25
JTWC TRACK ERRORS (WESTPAC - 96-120 Hours)

• 96 Hr 120 Hr
• 2004 206 275
• 2005 212 263
• 2006 216 309
• 187 214
• 301 447
• Goal 200 250

from Falvey et al., JTWC 2008 Report, 63th
Interdepartmental Hurricane Conference, St.
Petersburg, FL, 2009.
26
JTWC INTENSITY ERRORS(WESTPAC 24 - 120 Hours)

• 24 Hr 48 Hr 72 Hr 96Hr 120Hr
• 2004 11 17 21 23
  26
• 2005 12 18 24 25
  25
• 2006 13 17 20 22
  24
• 13 18 20 24 26
• 12 19 21 22 28

from Falvey et al., JTWC 2008 Report, 63th
Interdepartmental Hurricane Conference, St.
Petersburg, FL, 2009.