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Coupled Hurricane Atmosphere-Ocean Modeling System HWRF-HYCOM and Hurricane Forecast Performance. Hyun-Sook Kim B. Hundermark, D. Iredell, Y. Kwon, L. Liu, C. Lozano, J. O’Connor, N. Surgi, V. Tallapragada, B. Tuleya, and Z. Zhan. Marine Modeling and Analysis Branch
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Coupled Hurricane Atmosphere-Ocean Modeling System HWRF-HYCOM and Hurricane Forecast Performance Hyun-Sook Kim B. Hundermark, D. Iredell, Y. Kwon, L. Liu, C. Lozano, J. O’Connor, N. Surgi, V. Tallapragada, B. Tuleya, and Z. Zhan Marine Modeling and Analysis Branch Environmental Modeling Center (EMC)/NCEP/NOAA 5200 Auth Road Camp Springs, MD 207641
Data Assimilation (SST, SSH, Hydro.Graphic.Profiles) using 2D/3DVAR HWRF-HYCOM RTOFS* (HYCOM–Basin) O(4~17 km) • Real-Time • Ocean Forecast System • http://polar.ncep.noaa.gov/ofs IC BC GFS:O(25 km) meld Parametric Winds SST ATMOS. HWRF O(9 & 27 km) OCEAN HYCOM–regional O(8~14 km) * Wind-stress *Heat Fluxes *Precipitation *Atm. Pressure
5. IC RTOFS (daily run indpt) Remote sensing SST/SSH/Feature model to provide meso-scale features in GOM, and Cold wake Differences HWRF-POM (Operational HWRF) HWRF-HYCOM 1. Ocean Model POM HYCOM 2. Resolution O(20 km) & 23 levels O(8-14 km) & 26 hybrid layers 3. Tides No Yes Ready to couple tide & storm surge models 4. Mixing Mellor-Yamada Level 2.5 GISS 6. BC GDEM RTOFS (daily run indpt) 7. Nowcast Only Init. Stage GFS + Parametric Winds Update a storm location and intensity; Data assim.
HWRF-HYCOM: Model Domains in Atlantic Ocean O(8-14 km) O(4-17 km) O(~27 km) Dynamic, depending on a storm location & HWRF-Nest Moving domain (10 x 10o @4-km Resolution)
Work in progress to support operational Hurricane forecast • Explicit representation of waves: 3-way coupling atmosphere-ocean-waves (HWRF-HYCOM-WAVEWATCH III). • Eddy Resolving Global Ocean Modeling coupled with Ice model (1/12o) to provide IC/BC to Basin-scale Models, e.g., Atlantic RTOFS, Hurricane Eastern Pacific Ocean Model (HYCOM in collaboration with Navy). • Full data assimilation cycle in the Regional Ocean Hurricane Models. • Increase horizontal and vertical resolution in the Regional Ocean Hurricane Models.
HWRF-HYCOM simulation for Katrina Compared with 6-hourly GOES SST (http://svs.gsfc.nasa.gov/vis/a000000/a003200/a003222/index.html)
being presented Test Cases & More …
Katrina Rita Kyle Gustav TrackForecast Skill Comparison: Black – HYCOM Red – Operational • Conclusion: • Comparable to Op. • Coherent Forecast Summary: • Error is at the same order of magnitude; • Error bars are consistently smaller
Katrina Rita Gustav Kyle Intensity Forecast Skill Comparison : Black – HYCOM Red – Operational • Conclusion: • Comparable to Op. • Coherent Forecast Summary: • Error is at the same order of magnitude; • Error bars are consistently smaller
LoopCurrent Loop Current Example of Individual cycle performance Katrina Best: NHC fKat05: HWRF-HYCOM H08: Operational HWRF
Position Time 1. Ocean Response:SST Katrina SST loss rate (average): For a major Hurricane, e.g. Katrina ~0.3oC/6-hr For a weak storm, e.g. Kyles ~0.1oC/6-hr
Loop Currents Eddy Eddy LC GS 2. Ocean Response:MLD Rita Rita Size @34-kt MLD variation at storm passage: Kyle • Relatively large deepening for stronger storms • Relatively large variation at shallower waters
Latent Latent Sensible Sensible SST tau SST tau Ut: ~5 m/s Ut: ~8 m/s MLD: 1.2 m/6-hr MLD: 0.4 m/6-hr SST: -0.3oC/6-hr SST: -0.1oC/6-hr LH Flux: ~3000 W/m2(SST=29.6oC) LH Flux: ~1000 W/m2(SST=27.7oC) SST feedback:Snap Shot Analysis Rita, a strong storm Kyle, a weak storm Latent Sensible
Cold Wake Inertial Waves Example of Realistic Realization of Oceanic Response
Plan for Years 2009 & …: A. Further Improvements in the System to increase Track and Intensity Forecast Skill B. Transition to operations Real time exercises for 2009 Operational for 2010, if accepted C. 3-way coupling HWRF-HYCOM-WAVEWATCH III D. Global Model (1/12o) for IC/BC