Impact of Assimilating Ocean Velocity Observations Inferred from Lagrangian Drifter Data Using the NCOM-4DVAR

Matthew J. Carrier Naval Research Laboratory, Stennis Space Center, Mississippi

Search for other papers by Matthew J. Carrier in
Current site
Google Scholar
PubMed
Close
,
Hans Ngodock Naval Research Laboratory, Stennis Space Center, Mississippi

Search for other papers by Hans Ngodock in
Current site
Google Scholar
PubMed
Close
,
Scott Smith Naval Research Laboratory, Stennis Space Center, Mississippi

Search for other papers by Scott Smith in
Current site
Google Scholar
PubMed
Close
,
Gregg Jacobs Naval Research Laboratory, Stennis Space Center, Mississippi

Search for other papers by Gregg Jacobs in
Current site
Google Scholar
PubMed
Close
,
Philip Muscarella American Society for Engineering Education, Washington, D.C.

Search for other papers by Philip Muscarella in
Current site
Google Scholar
PubMed
Close
,
Tamay Ozgokmen University of Miami, Miami, Florida

Search for other papers by Tamay Ozgokmen in
Current site
Google Scholar
PubMed
Close
,
Brian Haus University of Miami, Miami, Florida

Search for other papers by Brian Haus in
Current site
Google Scholar
PubMed
Close
, and
Bruce Lipphardt University of Delaware, Newark, Delaware

Search for other papers by Bruce Lipphardt in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Eulerian velocity fields are derived from 300 drifters released in the Gulf of Mexico by The Consortium for Advanced Research on Transport of Hydrocarbon in the Environment (CARTHE) during the summer 2012 Grand Lagrangian Deployment (GLAD) experiment. These data are directly assimilated into the Navy Coastal Ocean Model (NCOM) four-dimensional variational data assimilation (4DVAR) analysis system in a series of experiments to investigate their impact on the model circulation. The NCOM-4DVAR is a newly developed tool for data analysis, formulated for weak-constraint data assimilation based on the indirect representer method. The assimilation experiments take advantage of this velocity data along with other available data sources from in situ and satellite measurements of surface and subsurface temperature and salinity. Three different experiments are done: (i) A nonassimilative NCOM free run, (ii) an assimilative NCOM run that utilizes temperature and salinity observations, and (iii) an assimilative NCOM run that uses temperature and salinity observations as well as the GLAD velocity observations. The resulting analyses and subsequent forecasts are compared to assimilated and future GLAD velocity and temperature/salinity observations to determine the performance of each experiment and the impact of the GLAD data on the analysis and the forecast. It is shown that the NCOM-4DVAR is able to fit the observations not only in the analysis step, but also in the subsequent forecast. It is also found that the GLAD velocity data greatly improves the characterization of the circulation, with the forecast showing a better fit to future GLAD observations than those experiments without the velocity data included.

Naval Research Laboratory Contribution Number JA/7320-13-1824.

Corresponding author address: Matthew J. Carrier, Naval Research Laboratory, Bldg. 1009, Balch Blvd., Stennis Space Center, MS 39529. E-mail: matthew.carrier@nrlssc.navy.mil

Abstract

Eulerian velocity fields are derived from 300 drifters released in the Gulf of Mexico by The Consortium for Advanced Research on Transport of Hydrocarbon in the Environment (CARTHE) during the summer 2012 Grand Lagrangian Deployment (GLAD) experiment. These data are directly assimilated into the Navy Coastal Ocean Model (NCOM) four-dimensional variational data assimilation (4DVAR) analysis system in a series of experiments to investigate their impact on the model circulation. The NCOM-4DVAR is a newly developed tool for data analysis, formulated for weak-constraint data assimilation based on the indirect representer method. The assimilation experiments take advantage of this velocity data along with other available data sources from in situ and satellite measurements of surface and subsurface temperature and salinity. Three different experiments are done: (i) A nonassimilative NCOM free run, (ii) an assimilative NCOM run that utilizes temperature and salinity observations, and (iii) an assimilative NCOM run that uses temperature and salinity observations as well as the GLAD velocity observations. The resulting analyses and subsequent forecasts are compared to assimilated and future GLAD velocity and temperature/salinity observations to determine the performance of each experiment and the impact of the GLAD data on the analysis and the forecast. It is shown that the NCOM-4DVAR is able to fit the observations not only in the analysis step, but also in the subsequent forecast. It is also found that the GLAD velocity data greatly improves the characterization of the circulation, with the forecast showing a better fit to future GLAD observations than those experiments without the velocity data included.

Naval Research Laboratory Contribution Number JA/7320-13-1824.

Corresponding author address: Matthew J. Carrier, Naval Research Laboratory, Bldg. 1009, Balch Blvd., Stennis Space Center, MS 39529. E-mail: matthew.carrier@nrlssc.navy.mil
Save
  • Barron, C. N., A. Birol Kara, P. J. Martin, R. C. Rhodes, and L. Smedstad, 2006: Formulation, implementation and examination of vertical coordinate choices in the Global Navy Coastal Ocean Model (NCOM). Ocean Modell., 11, 347–375, doi:10.1016/j.ocemod.2005.01.004.

    • Search Google Scholar
    • Export Citation
  • Bennett, A. F., 1992: Inverse Methods in Physical Oceanography. Cambridge University Press, 347 pp.

  • Bennett, A. F., 2002: Inverse Modeling of the Ocean and Atmosphere. Cambridge University Press, 234 pp.

  • Bleck, R., 2002: An oceanic general circulation model framed in hybrid isopycnic-Cartesian coordinates. Ocean Modell., 4, 55–88, doi:10.1016/S1463-5003(01)00012-9.

    • Search Google Scholar
    • Export Citation
  • Blumberg, A. F., and G. L. Mellor, 1987: A description of a three-dimensional coastal ocean circulation model. Three-Dimensional Coastal Ocean Models, N. Heaps, Ed., Amer. Geophys. Union, 1–16.

  • Carrier, M. J., and H. Ngodock, 2010: Background-error correlation model based on the implicit solution of a diffusion equation. Ocean Modell., 35, 45–53, doi:10.1016/j.ocemod.2010.06.003.

    • Search Google Scholar
    • Export Citation
  • Chua, B. S., and A. F. Bennett, 2001: An inverse ocean modeling system. Ocean Modell., 3, 137–165, doi:10.1016/S1463-5003(01)00006-3.

    • Search Google Scholar
    • Export Citation
  • Courtier, P., 1997: Dual formulation of four-dimensional variational assimilation. Quart. J. Roy. Meteor. Soc., 123, 2449–2461, doi:10.1002/qj.49712354414.

    • Search Google Scholar
    • Export Citation
  • Cummings, J. A., 2005: Operational multivariate ocean data assimilation. Quart. J. Roy. Meteor. Soc., 131, 3583–3604, doi:10.1256/qj.05.105.

    • Search Google Scholar
    • Export Citation
  • Fan, S., O. Lie-Yauw, and P. Hamilton, 2004: Assimilation of drifter and satellite data in a model of the northeastern Gulf of Mexico. Cont. Shelf Res., 24, 1001–1013, doi:10.1016/j.csr.2004.02.013.

    • Search Google Scholar
    • Export Citation
  • Hernandez, F., P. Y. Le Traon, and N. H. Barth, 1995: Optimizing a drifter cast strategy with a genetic algorithm. J. Atmos. Oceanic Technol., 12, 330–345, doi:10.1175/1520-0426(1995)012<0330:OADCSW>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Ide, K., L. Kuznetsov, and C. K. R. T. Jones, 2002: Lagrangian data assimilation for point vortex systems. J. Turbul., 3, 053, doi:10.1088/1468-5248/3/1/053.

  • Ishikawa, Y. I., T. Awaji, and K. Akimoto, 1996: Successive correction of the mean sea surface height by the simultaneous assimilation of drifting buoy and altimetric data. J. Phys. Oceanogr., 26, 2381–2397, doi:10.1175/1520-0485(1996)026<2381:SCOTMS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Kurapov, A. L., G. D. Egbert, J. S. Allen, and R. N. Miller, 2009: Representer-based analyses in the coastal upwelling system. Dyn. Atmos. Oceans, 48 (1–3), 198–218, doi:10.1016/j.dynatmoce.2008.09.002.

    • Search Google Scholar
    • Export Citation
  • Kurapov, A. L., D. Foley, P. T. Strub, G. D. Egbert, and T. S. Allen, 2011: Variational assimilation of satellite observations in a coastal ocean model off Oregon. J. Geophys. Res., 116, C05006, doi:10.1029/2010JC006909.

    • Search Google Scholar
    • Export Citation
  • Kuznetsov, L., K. Ide, and C. K. R. T. Jones, 2003: A method for assimilation of Lagrangian data. Mon. Wea. Rev., 131, 2247–2260, doi:10.1175/1520-0493(2003)131<2247:AMFAOL>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Marchesiello, P., J. C. McWilliams, and A. F. Shchepetkin, 2001: Open boundary conditions for long-term integration of regional oceanic models. Ocean Modell., 3, 1–20, doi:10.1016/S1463-5003(00)00013-5.

    • Search Google Scholar
    • Export Citation
  • Martin, P. J., 2000: Description of the Navy Coastal Ocean Model version 1.0. NRL Rep. NRL/FR/7322/00/9962, 45 pp. [Available from NRL, Code 7322, Bldg. 1009, Stennis Space Center, MS 39529-5004.]

  • Mellor, G. L., and T. Yamada, 1982: Development of a turbulence closure model for geophysical fluid problems. Rev. Geophys. Space Phys., 20, 851–875, doi:10.1029/RG020i004p00851.

    • Search Google Scholar
    • Export Citation
  • Molcard, A., L. I. Piterbarg, A. Griffa, T. M. Ozgokmen, and A. J. Mariano, 2003: Assimilation of drifter positions for the reconstruction of the Eulerian circulation field. J. Geophys. Res., 108, 3056, doi:10.1029/2001JC001240.

    • Search Google Scholar
    • Export Citation
  • Molcard, A., A. Griffa, and T. M. Ozgokmen, 2005: Lagrangian data assimilation in multilayer primitive equation ocean models. J. Atmos. Oceanic Technol., 22, 70–83, doi:10.1175/JTECH-1686.1.

    • Search Google Scholar
    • Export Citation
  • Ngodock, H. E., 2005: Efficient implementation of covariance multiplication for data assimilation with the representer method. Ocean Modell., 8, 237–251, doi:10.1016/j.ocemod.2003.12.005.

    • Search Google Scholar
    • Export Citation
  • Ngodock, H. E., and M. J. Carrier, 2013: A weak constraint 4D-Var Assimilation system for the Navy coastal ocean model using the representer method. Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications, Vol. II, S. K. Park and L. Xu, Eds., Springer-Verlag, 367–390, doi:10.1007/978-3-642-35088-7_15.

  • Nilsson, J. A. U., S. Dobricic, N. Pinardi, P. M. Poulain, and D. Pettenuzzo, 2012: Variational assimilation of Lagrangian trajectories in the Mediterranean Ocean forecasting system. Ocean Sci., 8 (2), 249–259, doi:10.5194/os-8-249-2012.

    • Search Google Scholar
    • Export Citation
  • Ozgokmen, T. M., A. Molcard, T. M. Chin, L. I. Piterbarg, and A. Griffa, 2003: Assimilation of drifter positions in primitive equation models of midlatitude ocean circulation. J. Geophys. Res., 108, 3238, doi:10.1029/2002JC001719.

    • Search Google Scholar
    • Export Citation
  • Roemmich, D., and Coauthors, 2001: Argo: The global array of profiling floats. Observing the Oceans in the 21st Century, C. J. Koblinsky and N. R. Smith, Eds., Melbourne Bureau of Meteorology, 248–257.

  • Rosmond, T. E., J. Teixeria, M. Peng, T. F. Hogan, and R. Pauley, 2002: Navy operational global prediction system (NOGAPS): Forcing for ocean models. Oceanography, 15, 99–106, doi:10.5670/oceanog.2002.40.

    • Search Google Scholar
    • Export Citation
  • Salman, H., L. Kuznetsov, and C. K. R. T. Jones, 2006: A method for assimilating Lagrangian data into a shallow-water-equation ocean model. Mon. Wea. Rev., 134, 1081–1101, doi:10.1175/MWR3104.1.

    • Search Google Scholar
    • Export Citation
  • Shchepetkin, A. F., and J. C. McWilliams, 2003: A method for computing horizontal pressure-gradient force in an oceanic model with nonaligned vertical coordinate. J. Geophys. Res., 108, 3090, doi:10.1029/2001JC001047.

    • Search Google Scholar
    • Export Citation
  • Shchepetkin, A. F., and J. C. McWilliams, 2005: The regional oceanic modeling system (ROMS): A split-explicit, free-surface, topography-following-coordinate oceanic model. Ocean Modell., 9, 347–404, doi:10.1016/j.ocemod.2004.08.002.

    • Search Google Scholar
    • Export Citation
  • Smagorinsky, J., 1963: General circulation experiments with the primitive equations. I: The basic experiment. Mon. Wea. Rev., 91, 99–164, doi:10.1175/1520-0493(1963)091<0099:GCEWTP>2.3.CO;2.

    • Search Google Scholar
    • Export Citation
  • Taillandier, V., A. Griffa, and A. Molcard, 2006: A variational approach for the reconstruction of regional scale Eulerian velocity fields from Lagrangian data. Ocean Modell., 13, 1–24, doi:10.1016/j.ocemod.2005.09.002.

    • Search Google Scholar
    • Export Citation
  • Weaver, A. T., and P. Courtier, 2001: Correlation modeling on the sphere using a generalized diffusion equation. Quart. J. Roy. Meteor. Soc., 127, 1815–1846, doi:10.1002/qj.49712757518.

    • Search Google Scholar
    • Export Citation
  • Yaremchuk, M., M. Carrier, S. Smith, and G. Jacobs, 2013: Background error correlation modeling with diffusion operators. Data Assimilation for Atmospheric, Oceanic and Hydrologic Applications, Vol II, S. K. Park and L. Xu, Eds., Springer-Verlag, 177–203, doi:10.1007/978-3-642-35088-7_8.

  • Yu, P., A. L. Kurapov, G. D. Egbert, J. S. Allen, and A. P. Kosro, 2012: Variational assimilation of HF radar surface currents in a coastal ocean model off Oregon. Ocean Modell., 49–50, 86–104, doi:10.1016/j.ocemod.2012.03.001.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 1813 893 191
PDF Downloads 415 103 4