National Oceanic and Atmospheric Administration

Atlantic Oceanographic and Meteorological Laboratory

Physical Oceanography Division

Dr. George Halliwell


4301 Rickenbacker Causeway,
Miami, FL 33149, USA
Phone: (305) 361-4346

Research Interests

  • Regional ocean modeling.
  • Ocean forecasting.
  • Ocean forecast model improvement for hurricane forecasting.
  • Ocean observing system impact assessments.

Current Work

    George Halliwell performs data-assimilative regional ocean modeling using the HYbrid Coordinate Ocean Model (HYCOM) in support of several research activities:

  • Develop, improve, and apply regional ocean forecast systems to a variety of oceanographic problems such as the transport and dispersion of oil spills and marine debris.
  • Evaluate and improve ocean model performance in coupled hurricane forecast models with the overarching goal of improving intensity forecasts. Collaborate with the operational hurricane modelers at NOAA/EMC to improve operational hurricane forecast models.
  • Develop and validate a relocatable ocean Observing System Simulation Experiment (OSSE) system to evaluate the impact of new and altered ocean observing systems. Conduct experiments to evaluate both existing and new ocean observing systems for their impact on improving the initialization and performance of ocean forecast models.
  • Co-director of the joint AOML/CIMAS/RSMAS Ocean Modeling and OSSE Center (OMOC;


Halliwell, Jr. G.R ., V. Kourafalou, M. Le Henaff, L.K. Shay, and R. Atlas, 2015: OSSE impact analysis of airborne ocean surveys for improving upper-ocean dynamical and thermodynamical forecasts in the Gulf of Mexico. Progress in Oceanography , 130:32-46, doi:10.1016/j.pocean.2014.09.004. [pdf]

Halliwell, G.R ., S. Gopalakrishnan, F. Marks, and D. Willey. Idealized study of ocean impacts on tropical cyclone intensity forecasts. Monthly Weather Review, doi:10.1175/MWR-D-14-00022.1, in press, 2015.

Oke, P., G. Larnicol, E. M. Jones, V. Kourafalou, A. K. Sperrevik, F. Carse, C. A. S. Tanajura, B. Mourre, M. Tonani, G. B. Brassington, M. Le Hénaff, G. R. Halliwell , Jr., R. Atlas, A. M. Moore, C. A. Edwards, M. J. Martin, A. A. Sellar, A. Alvarez, P. De Mey, and M. Iskandarani, 2014: Assessing the impact of observations on ocean forecasts and reanalyses: Part 2, regional applications. J. Operational Oceanogr ., in press, 2015.

Halliwell, Jr., G. R ., A. Srinivasan, V. Kourafalou, H Yang, D. Willey, M. Le Henaff, and R. Atlas, 2014. Rigorous evaluation of a fraternal twin ocean OSSE system in the open Gulf of Mexico. J. Atmos. Ocean. Technol. , 31, 105-130 (doi:10.1175/JTECH-D-13-00011. 1). [pdf]

Bozec, A., E.P. Chassignet, M.S. Lozier, and G.R. Halliwell, 2011: On the variability of the Mediterranean outflow water in the Atlantic Ocean. J. Geophys. Res., 116, C09033, doi:10.1029/2011JC007191. [pdf]

Halliwell, G.R. Jr., L.K. Shay, J. Brewster, and W.J. Teague, 2011: Evaluation and sensitivity analysis to an ocean model response to hurricane Ivan. Mon. Weather Rev., 139(3):921-945 [pdf]

Jaimes, B., L.K. Shay, and G.R. Halliwell, 2011: The response of quasi-geostrophic oceanic vortices to tropical cyclone forcing. J. Phys. Oceanogr., 41:1965-1985, doi:10.1175/JPO-D-11-06.1. [pdf]

Mariano, A.J., G.R. Halliwell, V. Kourafalou, E. Ryan, A. Srinivasan, and M. Roffer 2011: On the modeling of the 2010 Gulf of Mexico oil spill. Dynam. Atmos. Oceans., 52:322-340, doi:10.1016/j.dynatmoce.2011.06.001 [pdf]

Shay, L.K., B. Jaimes, J.K. Brewster, P. Meyers, E. Claire McCaskill, E. Uhlhorn, F. Marks, G.R. Halliwell, Jr., O-M Smedstad, and P. Hogan, 2011: Airborne ocean surveys of the Loop Current complex from NOAA WP-3D in support of the Deep Water Horizon oil spill. In: Monitoring and Modeling the Deepwater Horizon Oil Spill: A Record-Breaking Enterprise, Liu et al., Eds., AGU Monograph Series, 131-151. [pdf]

Goni G.J., M. DeMaria, J. Knaff, C. Sampson, J. Price , A. Mehra, I. Ginis, I-I Lin, P. Sandery, S. Ramos-Buarque, M. M. Ali, F. Bringas, S. Aberson, R. Lumpkin, G. Halliwell, C. Lauer, E. Chassignet, A. Mavume, and K. Kang, 2010: The ocean observing system for tropical cyclone intensification forecasts and studies. In Proceedings of the "OceanObs'09: Sustained Ocean Observations and Information for Society" Conference (Vol. 2), Venice, Italy, 21-25 September 2009, Hall, J., Harrison D.E. and Stammer, D., Eds., ESA Publication WPP-306. [pdf]

Chassignet, E. P., H. E. Hurlburt, E. J. Metzger, O. M. Smedstad, J. A. Cummings, G. R. Halliwell, R. Bleck, R. Baraille, A. J. Wallcraft, C. Lozano, H. L. Tolman, A. Srinivasan, S. Hankin, P. Cornillon, R. Weisberg, A. Barth, R. He, F. Werner, and J. Wilkin, 2009: U. S. GODAE: Global Ocean Prediction with the HYbrid Coordinate Ocean Model (HYCOM). Oceanogr., 22(2), special issue: Excellence in Partnering award winners, 64-75. [pdf]

Goni G. J., M. DeMaria, J. Knaff, C. Sampson, I. Ginis, F. Bringas, A. Mavume, C. Lauer, I-I Lin, M. M. Ali, Paul Sandery, S. Ramos-Buarque, K. Kang , A. Mehra, E. Chassignet, and G. Halliwell, 2009: Applications of satellite-derived ocean measurements to tropical cyclone intensity forecasting. Oceanogr., 22(3):176-183. [pdf]

Halliwell, G.R., A. Barth, R.H. Weisberg, P. Hogan, O.M. Smedstad, and J. Cummings, 2009: Impact of GODAE products on nested HYCOM simulations of the West Florida Shelf. Ocean Dyn., 59(1):139-155 [pdf]

Peng, G., Z. Garraffo, G.R. Halliwell, O.M. Smedstad, C. S. Meinen, V. Kourafalou, and P. Hogan, 2009: Temporal variabaility of the Florida Current transport at 27N. In Ocean Circulation and El Nino: New Research, J.A. Long and D.S. Wells (ed.). Nova Science Publishers, New York, 119-137 [pdf]

Wallcraft, A. J., A. B. Kara, H. E. Hurlburt, E.P. Chassignet, and G. R. Halliwell, 2008: Value of bulk heat flux parameterizations for ocean SST prediction. J. Mar. Sys. [pdf]

Halliwell Jr. G. R., L.K. Shay, Jacob, Smedstad OM, Uhlhorn EW, 2008: Improving ocean model initialization for coupled tropical cyclone forecast models using GODAE nowcasts. Mon. Wea. Rev., 136, 2576-2591. [pdf]

Chassignet, E. P., H. E. Hurlburt, O. M. Smedstad, G. R. Halliwell, P. J. Hogan, A. J. Wallcraft, and R. Bleck, 2007: Ocean Prediction with the HYbrid Coordinate Ocean Model (HYCOM). J. Marine Systems, 65, 60-83. [pdf]

Olascoaga, M. J., I. I. Rypina, M. G. Brown, F. J. Beron-Vera, H. Kocak, L. E. Brand, G. R. Halliwell, and L. K. Shay, 2006: Persistent Transport Barrier on the West Florida Shelf. Geophys. Res. Lett., 33, L22603, doi: 10.1029/2006GL027800. [pdf]

Chassignet, E.P., H.E. Hurlburt, O.M. Smedstad, G.R. Halliwell, P.J. Hogan, A.J. Wallcraft, and R. Bleck, 2006: Ocean prediction with the Hybrid Coordinate Ocean Model (HYCOM) In: Ocean Weather Forecasting: An Integrated View of Oceanography, Chassignet, E.P., and J. Verron (Eds.), Springer, 413-426. [pdf]

Chassignet, E. P., H. E. Hurlburt, O. M. Smedstad, G. R. Halliwell, A. J. Wallcraft, E. J. Metzger, B. O. Blanton, C. Lozano, D. B. Rao, P. J. Hogan, and A. Srinivasan, 2006: Generalized vertical coordinates for eddy resolving global and coastal ocean forecasts. Oceanogr., 19, 20-31. [pdf]

Halliwell, Jr., G.R., 2004: Evaluation of Vertical Coordinate and Vertical Mixing Algorithms in the Hybrid-Coordinate Ocean Model (HYCOM). Ocean Modelling, 7, 285-322. [pdf]

Shaji, C., C. Wang, G.R. Halliwell, Jr., and A.J. Wallcraft, 2004: Simulation of Tropical Pacific and Atlantic Oceans using hybrid coordinate ocean model. Ocean Modelling, 9, 253-282. [pdf]

Thacker, W.C., S-K Lee, and G.R. Halliwell, Jr., 2004: Assimilating twenty years of Atlantic XBT data HYCOM: A first look. Ocean Modelling, 7,183-210. [pdf]

Chassignet, E.P., L. Smith, G.R. Halliwell, and R. Bleck, 2003: North Atlantic simulation with the hybrid coordinate ocean model (HYCOM): Impact of the vertical coordinate choice and resolution, reference density, and thermobaricity. J. Phys. Oceanogr., 33, 2504-2526. [pdf]

Halliwell, Jr., G.R., R. H. Weisberg, and D.A. Mayer, 2003: A synthetic float analysis of upper-limb meridional overturning circulation interior ocean pathways in the tropical/subtropical Atlantic. In: Interhemispheric Water Exchange in the Atlantic Ocean, G. Goni and P. Malanotte-Rizzoli, editors, Elsevier Publishing Company, 93-136. [pdf]

Halliwell, Jr., G.R., 1998: Simulation of North Atlantic decadal/multi-decadal SST anomalies driven by basin-scale atmospheric circulation anomalies. J. Phys. Oceanogr., 28, 5-21. [pdf]

Halliwell, Jr., G.R., 1997: Decadal and multi-decadal North Atlantic SST anomalies driven by basin-scale atmospheric anomalies. J. Climate, 10, 2405-2411. [pdf]

Halliwell, Jr., G.R. and D.A. Mayer, 1996: Frequency response properties of forced climatic SST anomaly variability in the North Atlantic. J. Climate, 9, 3575-3587. [pdf]

Halliwell, Jr., G.R., G. Peng and D.B. Olson, 1994: Stability of the Sargasso Sea Subtropical Convergence Zone. J. Phys. Oceanogr., 24, 1166-1183. [pdf]

Halliwell, Jr., G.R., P. Cornillon and D.A. Byrne, 1991: Westward-propagating SST anomaly features in the Sargasso Sea, 1982-88. J. Phys. Oceanogr., 21, 635-649. [pdf]

Halliwell, Jr., G.R., Y.J. Ro and P. Cornillon, 1991: Westward-propagating SST anomalies and baroclinic eddies in the Sargasso Sea. J. Phys. Oceanogr., 21, 1664-1680. [pdf]

Hanson, H.P., V.M. Halliwell, P. Cornillon, G.R. Halliwell, Jr. and E. Bohm, 1991: Climatological perspectives, oceanographic and meteorological, on variability in the subtropical convergence zone in the northwestern Atlantic. J. Geophys. Res., 96, 8517-8529. [pdf]

Halliwell, Jr., G.R., P. Cornillon, K.H. Brink, R.T. Pollard, D.L. Evans, L.A. Regier, J.M. Toole and R.W. Schmitt, 1991: Descriptive oceanography during FASINEX: Medium to large-scale variability. J. Geophys. Res., 96, 8553-8567. [pdf]

Halliwell, Jr., G.R. and P. Cornillon, 1990: Large-scale SST variability in the western North Atlantic subtropical convergence zone during FASINEX. Part 2: Upper ocean heat balance and frontogenesis. J. Phys. Oceanogr., 20, 223-234. [pdf]

Halliwell, Jr., G.R. and P. Cornillon, 1990: Large-scale SST variability in the western North Atlantic subtropical convergence zone during FASINEX. Part 1: Description of SST and wind stress fields. J. Phys. Oceanogr., 20, 209-222. [pdf]

Halliwell, Jr., G.R. and P. Cornillon, 1989: Large-scale SST anomalies associated with subtropical fronts in the western North Atlantic during FASINEX. J. Mar. Res., 47, 757-775. [pdf]

Halliwell, Jr., G.R. and J.S. Allen, 1987: Wavenumber-frequency domain properties of the coastal sea level response to alongshore wind stress along the west coast of North America, 1980-84. J. Geophys. Res., 92, 11761-11788. [pdf]

Halliwell, Jr., G.R. and J.S. Allen, 1987: The large-scale coastal wind field along the west coast of North America 1981-82. J. Geophys. Res., 92, 1861-1884. [pdf]

Brink, K.H., D.C. Chapman and G.R. Halliwell, Jr., 1987. A stochastic model for wind-driven currents over the continental shelf. J. Geophys. Res., 92, 1861-1884. [pdf]

Halliwell, Jr., G.R. and J.S. Allen, 1984: Large-scale sea level response to atmospheric forcing along the west coast of North America, summer 1973. J. Phys. Oceanogr., 14, 864-886. [pdf]

Halliwell, Jr., G.R. and C.N.K. Mooers, 1983: Meanders of the Gulf Stream downstream of Cape Hatteras, 1975-1978. J. Phys. Oceanogr., 13, 1275-1292. [pdf]

Halliwell, Jr., G.R. and C.N.K. Mooers, 1979: The space-time structure and variability of the shelf water-slope water and Gulf Stream surface temperature fronts and associated warm-core eddies. J. Geophys. Res., 84, 7707-7727. [pdf]