The feasibility of global ocean weather prediction was just emerging as the Global Ocean Data Assimilation Experiment (GODAE) began in 1997. Ocean weather includes phenomena such as meandering currents and fronts, eddies, the surface mixed layer and sea surface temperature (SST), equatorial and coastally trapped waves, upwelling of cold water, and Rossby waves, all influencing ocean variables such as temperature (T), salinity (S), currents, and sea surface height (SSH). Adequate real-time data input, computing power, numerical ocean models, data assimilation capabilities, atmospheric forcing, and bathymetric/boundary constraints are essential to make such prediction possible. The key observing systems and real-time data inputs are SSH from satellite altimetry, satellite and in situ SST, T, or T and S profiles (e.g., Argo, TAO/Triton, PIRATA moored array in the Atlantic, bathythermographs), and atmospheric forcing. The ocean models dynamically interpolate data in conjunction with data assimilation, convert atmospheric forcing into oceanic responses, and forecast the ocean weather, applying bathymetric/boundary constraints in the process. The results are substantially influenced by ocean model simulation skill and it is advantageous to use an ocean model that is eddy-resolving (nominally 1/10° or finer), not just eddy-permitting. Because the most abundant ocean observations are satellite surface data, and subsurface data are very sparse in relation to the spatial scales of the mesoscale ocean features that dominate the ocean interior, downward projection of surface data is a key challenge in ocean data assimilation. The need for accurate prediction of ocean features that are inadequately observed, such as mixed layer depth, places a major burden on the ocean model, data assimilation, and atmospheric forcing. The sensitivity of ocean phenomena to atmospheric forcing and the time scale for response affect the time scale for oceanic predictive skill, sensitivity to the initial state versus the atmospheric forcing as a function of forecast length, and thus oceanic data requirements and prediction system design. Outside of surface boundary layers and shallow regions, forecast skill is about one month globally and over many subregions, and is only modestly reduced by using climatological forcing after the end of atmospheric forecasts versus using analysis-quality forcing for the duration. In addition, global ocean prediction systems must demonstrate the ability to provide initial and boundary conditions to nested regional and coastal models that enhance their predictive skill. Demonstrations of feasibility in relation to the preceding phenomena, requirements, and challenges are drawn from the following global and basin-scale ocean prediction systems: BLUElink> (Australia), the HYbrid Coordinate Ocean Model (HYCOM; USA), Mercator (France), Multivariate Ocean Variational Estimation/Meteorological Research Institute Community Ocean Model (MOVE/MRI.COM; Japan), and the Naval Research Laboratory Layered Ocean Model (NLOM; USA).
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Volume 22, No. 3
Pages 110 - 127
High-Resolution Global and Basin-Scale Ocean Analyses and Forecasts
By Harley E. Hurlburt , Gary B. Brassington, Yann Drillet , Masafumi Kamachi, Mounir Benkiran , Romain Bourdallé-Badie, Eric P. Chassignet , Gregg A. Jacobs , Olivier Le Galloudec , Jean-Michel Lellouche, E. Joseph Metzger , Peter R. Oke , Timothy F. Pugh, Andreas Schiller , Ole Martin Smedstad , Benoit Tranchant , Hiroyuki Tsujino , Norihisa Usui , and Alan J. Wallcraft
Hurlburt, H.E., G.B. Brassington, Y. Drillet, M. Kamachi, M. Benkiran, R. Bourdallé-Badie, E.P. Chassignet, G.A. Jacobs, O. Le Galloudec, J.-M. Lellouche, E.J. Metzger, P.R. Oke, T.F. Pugh, A. Schiller, O.M. Smedstad, B. Tranchant, H. Tsujino, N. Usui, and A.J. Wallcraft. 2009. High-resolution global and basin-scale ocean analyses and forecasts. Oceanography 22(3):110–127, https://doi.org/10.5670/oceanog.2009.70.
Ambe, D., S. Imawaki, H. Uchida, and K. Ichikawa. 2004. Estimating the Kuroshio axis south of Japan using a combination of satellite altimetry and drifting buoys. Journal of Oceanography 60:375–382.
Barnier, B., G. Madec, T. Penduff, J.-M. Molines, A.-M. Treguier, J. Le Sommer, A. Beckman, A. Biastoch, C. Böning, J. Dengg, and others. 2006. Impact of partial steps and momentum advection schemes in a global ocean circulation model at eddy-permitting resolution. Ocean Dynamics 56:543–567, doi:10.1007/s10236-006-0082-1.
Bloom, S.C., L.L. Takacs, A.M. da Silva, and D. Ledvina. 1996. Data assimilation using incremental analysis updates. Monthly Weather Review 124:1,256–1,271.
Brasseur, P., and J. Verron. 2006. The SEEK filter method for data assimilation in oceanography: A synthesis. Ocean Dynamics 56:650–661.
Brassington, G.B., T. Pugh, C. Spillman, E. Schulz, H. Beggs, A. Schiller, and P.R. Oke. 2007. BLUElink> Development of operational oceanography and servicing in Australia. Journal of Research and Practice in Information Technology 39(2):151–164.
Bryan, F.O., M.W. Hecht, and R.D. Smith. 2007. Resolution convergence and sensitivity studies with North Atlantic circulation models. Part I. The western boundary current system. Ocean Modelling 16:141–159.
Chassignet, E.P., H.E. Hurlburt, E.J. Metzger, O.M. Smedstad, J. Cummings, G.R. Halliwell, R. Bleck, R. Baraille, A.J. Wallcraft, C. Lozano, and others. 2009. US GODAE: Global ocean prediction with the HYbrid Coordinate Ocean Model (HYCOM). Oceanography 22(2):64–75.
Chassignet, E.P., and D.P. Marshall. 2008. Gulf Stream separation in numerical ocean models. Pp. 39–61 in Ocean Modeling in an Eddying Regime, Geophysical Monograph 177. M.W. Hecht and H. Hasumi, eds, American Geophysical Union, Washington, DC.
Chelton, D.B., R.A. deSzoeke, and M.G. Schlax. 1998. Geographical variability of the first baroclinic Rossby radius of deformation. Journal of Physical Oceanography 28(3):433–460.
Clark, C., and the In Situ Observing System Authors, and S. Wilson and the Satellite Observing System Authors. 2009. An overview of global observing systems relevant to GODAE. Oceanography 22(3):22–33.
Csanady, G.T. 2001. Air-Sea Interactions: Laws and Mechanisms. Cambridge University Press, New York, 248 pp.
Cummings, J.A. 2005. Operational multivariate ocean data assimilation. Quarterly Journal of the Royal Meteorological Society 131(613):3,583–3,604.
Cummings, J., L. Bertino, P. Brasseur, I. Fukumori, M. Kamachi, M.J. Martin, K. Mogensen, P. Oke, C.E. Testut, J. Verron, and A. Weaver. 2009. Ocean data assimilation systems for GODAE. Oceanography 22(3):96–109.
Daley, R. 1991. Atmospheric Data Analysis. Cambridge University Press, Cambridge, 457 pp.
Dombrowsky, E., L. Bertino, G.B. Brassington, E.P. Chassignet, F. Davidson, H.E. Hurlburt, M. Kamachi, T. Lee, M.J. Martin, S. Mei, and M. Tonani. 2009. GODAE systems in operation. Oceanography 22(3):80–95.
Donlon, C.J., K.S. Casey, I.S. Robinson, C.L. Gentemann, R.W. Reynolds, I. Barton, O. Arino, J. Stark, N. Rayner, P. LeBorgne, and others. 2009. The GODAE High-Resolution Sea Surface Temperature Pilot Project. Oceanography 22(3):34–45.
Ducet, N., P.Y. Le Traon, and G. Reverdin. 2000. Global high-resolution mapping of ocean circulation from TOPEX/Poseidon and ERS-1 and -2. Journal of Geophysical Research 105(C8):19,477–19,498.
Emery, W.J., W.G. Lee, and L. Magaard. 1984. Geographic and seasonal distributions of Brunt-Väisälä frequency and Rossby radii in the North Pacific and North Atlantic. Journal of Physical Oceanography 14:294–317.
Griffies, S.M., M.J. Harrison, R.C. Pacanowski, and A. Rosati. 2004. A Technical Guide to MOM4. GFDL Ocean Group Technical Report No. 5, National Oceanic and Atmospheric Administration/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, 339 pp.
Hurlburt, H.E., and P.J. Hogan. 2000. Impact of 1/8° to 1/64° resolution on Gulf Stream model-data comparisons in basin-scale subtropical Atlantic Ocean models. Dynamics of Atmospheres and Oceans 32:283–329.
Hurlburt, H.E., and P.J. Hogan. 2008. The Gulf Stream pathway and the impacts of the eddy-driven abyssal circulation and the Deep Western Boundary Current. Dynamics of Atmospheres and Oceans 45:71–101.
Hurlburt, H.E., E.P. Chassignet, J.A. Cummings, A.B. Kara, E.J. Metzger, J.F. Shriver, O.M. Smedstad, A.J. Wallcraft, and C.N. Barron. 2008a. Eddy-resolving global ocean prediction. Pp. 353–381 in Ocean Modeling in an Eddying Regime, Geophysical Monograph 177. M.W. Hecht and H. Hasumi, eds, American Geophysical Union, Washington, DC.
Hurlburt, H.E., Y. Drillet, G.B. Brassington, M. Benkiran, E.P. Chassignet, J.A. Cummings, M. Drevillon, H. Etienne, O. Le Galloudec, E.J. Metzger, and others. 2009. Global high resolution analyses and forecasts at the mesoscale. Pp. 95–111 in Proceedings Final GODAE Symposium, November 12–15, 2008, Nice, France.
Hurlburt, H.E., D.N. Fox, and E.J. Metzger. 1990. Statistical inference of weakly correlated subthermocline fields from satellite altimeter data. Journal of Geophysical Research 95(C7):11,375–11,409.
Hurlburt, H.E., E.J. Metzger, P.J. Hogan, C.E. Tilburg, and J.F. Shriver. 2008b. Steering of upper ocean currents and fronts by the topographically constrained abyssal circulation. Dynamics of Atmospheres and Oceans 45:102–134.
Johns, W.E., T.J. Shay, J.M. Bane, and D.R. Watts. 1995. Gulf Stream structure, transport, and recirculation near 68°W. Journal of Geophysical Research 100(C1):817–838.
Kanamitsu, M., W. Ebisuzaki, J. Woollen, S.-K. Yang, J.J. Hnilo, M. Fiorino, and G.L. Potter. 2002. NCEP-DOE AMIP-II reanalysis (R-2). Bulletin of the American Meteorological Society 83:1,631–1,643.
Kara, A.B., and H.E. Hurlburt. 2006. Daily inter-annual simulations of SST and MLD using atmospherically-forced OGCMs: Model evaluation in comparison to buoy time series. Journal of Marine Systems 62:95–119.
Lumpkin, R., and M. Pazos. 2007. Measuring surface currents with SVP drifters: The instrument, its data, and some recent results. Pp. 39–67 in Lagrangian Analysis and Prediction of Coastal and Ocean Dynamics. A. Griffa, A.D. Kirwan, A.J. Mariano, T. Özgökmen, and T. Rossby, eds, Cambridge University Press, New York.
Madec, G. 2008. NEMO Ocean Engine. Report 27, ISSN No. 1288-1619. Institut Pierre-Simon Laplace (IPSL), France, 197 pp.
National Oceanic and Atmospheric Administration, Office of Oceanic and Atmospheric Research Climate Program Office, Climate Observation Division. 2008. Program Plan for Building a Sustained Ocean Observing System for Climate. Available online at: http://www.oco.noaa.gov/docs/programplan_current.doc (accessed December 2008).
Oh, I.S., V. Zhurbas, and W.S. Park. 2000. Estimating horizontal diffusivity in the East Sea (Sea of Japan) and the northwest Pacific from satellite-tracked drifter data. Journal of Geophysical Research 105(C3):6,483–6,492.
Oke, P.R., G.B. Brassington, D.A. Griffin, and A. Schiller. 2008. The Bluelink ocean data assimilation system (BODAS). Ocean Modelling 21:46–70.
Pickart, R.S., and D.R. Watts. 1990. Deep Western Boundary Current variability at Cape Hatteras. Journal of Marine Research 48:765–791.
Ridgeway, K.R., and J.R. Dunn. 2003. Mesoscale structure of the mean East Australian Current system and its relationship to topography. Progress in Oceanography 56:190–222.
Roemmich, D., and the Argo Steering Team. 2009. Argo: The challenge of continuing 10 years of progress. Oceanography 22(3):46–55.
Rosmond, T.E., J. Teixeira, M. Peng, T.F. Hogan, and R. Pauley. 2002. Navy Operational Global Atmospheric Prediction System (NOGAPS): Forcing for ocean models. Oceanography 15(1):99–108.
Schiller, A., P.R. Oke, G.B. Brassington, M. Entel, R. Fiedler, D.A. Griffin, J. Mansbridge. 2008. Eddy-resolving ocean circulation in the Asian-Australian region inferred from an ocean reanalysis effort. Progress in Oceanography 76:334–365.
Shriver, J.F., H.E. Hurlburt, O.M. Smedstad, A.J. Wallcraft, and R.C. Rhodes. 2007. 1/32° real-time global ocean prediction and value-added over 1/16° resolution. Journal of Marine Systems 65:3–26.
Tsujino, H., N. Usui, and H. Nakano. 2006. Dynamics of Kuroshio path variations in a high-resolution general circulation model. Journal of Geophysical Research 111, C11001, doi:10.1029/2005JC003118.
Usui, N., H. Tsujino, and Y. Fujii. 2006. Short-range prediction experiments of the Kuroshio path variabilities south of Japan. Ocean Dynamics 56:607–623.
Usui, N., H. Tsujino, Y. Fujii, and M. Kamachi. 2008a. Generation of a trigger meander for the 2004 Kuroshio large meander. Journal of Geophysical Research 113, C01012, doi:10.1029/2007JC004266.
Usui, N., H. Tsujino, H. Nakano, and Y. Fujii. 2008b. Formation process of the Kuroshio large meander in 2004. Journal of Geophysical Research 113, C08047, doi:10.1029/2007JC004675.
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