Providing Environmental Awareness for the Urban

Ocean

Alan F. Blumberg and

Nickitas Georgas

Davidson Laboratory August 22 -23, 2013

New York Harbor Observing and Prediction System

Integrated system of observing sensors and forecast modelsTO OBSERVE TO PREDICTTO COMMUNICATE Weather Currents Water Level Salinity Temperature Waves

3D Circulation Model (ECOM/POM-derived):Boussinesq, Hydrostatic, Primitive Equation, Sigma Coordinate

ModelMode Splitting: 10 external/internal steps, Δte=1sec. Smagorinksy lateral diffusion: HORCON=0.01, Prandtl

Number=1000!Mellor-Yamada 2.5-Kl vertical closure: UMOL=10-6 m2/s.Bottom stress: CDmin=3x10-3, z0=10-

3m, everywhere!*Modified by dynamic wave boundary layer (Grant-Madsen)!

Surface Wind Stress: Large and Pond 1982.Barometric Pressure Gradient forcing: Switched off.2D Surface Heat Fluxes: Ahsan and Blumberg, QUAL-2E-type.

*Modified for 10m winds, generalized for UTC or local time coordinate.

Robust, explicit, wetting and drying.

Dynamically Coupled, Surface Wind Wave Model (GLERL-derived):Empirical Wave Momentum Model, JONSWAP spectrum.Wind-wave growth equation: γ=2.8%, CDs=0.7x10-3,

,z0w=σ/5.Incl. Bottom dissipation: fw=0.04Incl. Depth-induced breaking: γB=0.8261 (Longuet-Higgins and

Fenton, 1974).*Dynamic depth from circulation model.

Incl. Offshore wave boundary condition. Adopted new dispersion eqn. for shallows.

Included and validated Thin Dams (obstruction grids).Standardized, CF-protocol-compliant, NetCDF Outputs.

sECOM Hydrodynamic Model. NYHOPS App.

Bathymetry:Over 1M soundings!

Resolution: 4km -> 25m

DE

NJ

CT RINY

NYC

NYHOPS Forecast Model _ it is all about realism! 3D General Circulation Model dynamically coupled with Surface Wind-Wave modelInput forcing:(O): Observed(F): Forecasted(H): Historic Tides (O+F) NOS Offshore Surge and Steric (O+F) NOS Offshore Waves (O+F) Surface Winds (O+F) NAM 12km Heating and Cooling (O+F) 239 Rivers and Streams (O+F) NERFC 280 Major Dischargers (H) River Ice (O+F)

Output: hindcasts+forecasts 4x/day Results every 10min, since 2006.Total water level.3D Currents, Salinity, Temperature.Significant wave height and wave period. Colored DOM and light absorption.

+

1967

+Real timeObservatio

ns

External dataand models

Distributed Inflows and Effluents

A fully automated system of systemsNew York Harbor Observing and Prediction

System

0.5 hrs + 1.5 hrs + 2.0 hrs

ValidationEvery model has errors. Validation tells us that they are sufficiently small.

Adopted NOAA/NOS Model Evaluation Software (DB-MEE).2 years of recent in situ data: 2007-2009; 6+ years of real-time experienceOver 100 local stations (Georgas and Blumberg ‘10, DiLiberto et al ’11, etc.)T/S vertical transect profiles from gliders (Georgas and Blumberg ‘08)Satellite SST comparisons (Bhushan ‘09, Bhushan, Blumberg, Georgas ‘10)HF-radar (Gopalakrishnan ‘11) and surface drifters (Blumberg et al, forthcoming).

Marine Search and Rescue (SAR) Missions…………

NY/NJ Harbor Commercial Pilots & Schedulers (Harbor Pilots Associations, Marine Transportation)……………

Recreational Boaters (Regattas, Kayaks,…)………………..

Coastal Flooding Responders (PD, FEMA, NWS)……

Scientists/Engineers……

NYHOPS supports:

New York Harbor Observing and Prediction System

Sandysurge Post-Sandy

Nor’easter

1

Totals for Sandy’s forecast period: 30,334 unique hits.

The NYHOPS/SSWS forecast water elevation (posted Saturday at 6am): - Along coast of NJ/NY and all

of the Hudson River were within 5%,

- the Battery, NY was low by 20%,

- Long Island Sound was low by 10%

ConclusionsNYHOPS established as an urban ocean forecast system –

large following – extensive validationMARACOOS assets a blessing – hf radar, drifters, gliders and

“met forcing”Need more robust assimilation – bring in mobile sensors,

including truncated fisheries dataNeed better offshore boundary forcingStudy wave and wave-driven set-up modelingFaster code… offsite mirroring… online data storeThank you NWS & NCEP & NOS– great operational productsLinks needed to National Hurricane Center collection of

hurricane models;Include infrastructure ensembles/probabilistic forecasts;

Thank You! ablumberg@stevens.edu