A 4DVAR System for the Navy Coastal Ocean Model. Part 1: System Description and Assimilation of Synthetic Observations in Monterey Bay

AbstractA 4D variational data assimilation system was developed for assimilating ocean observations with the Navy Coastal Ocean Model. It is described in this paper, along with initial assimilation experiments in Monterey Bay using synthetic observations. The assimilation system is tested in a series of twin data experiments to assess its ability to fit assimilated and independent observations by controlling the initial conditions and/or the external forcing while assimilating surface and/or subsurface observations. In all strong and weak constraint experiments, the minimization of the cost function is done with both the gradient descent method (in the control space) and the representer method (observation space). The accuracy of the forecasts following the analysis and the relevance of the retrieved forcing correction in the case of weak constraints are evaluated. It is shown that the assimilation system generally fits the assimilated and nonassimilated observations well in all experiments, yielding lowe...

[1]  John Derber,et al.  A Global Oceanic Data Assimilation System , 1989 .

[2]  R. Daley.  Atmospheric Data Analysis , 1991 .

[3]  Patricia A. Phoebus,et al.  The navy's operational atmospheric analysis , 1992 .

[4]  T. Rosmond.  The Design and Testing of the Navy Operational Global Atmospheric Prediction System , 1992 .

[5]  Andrew F. Bennett,et al.  Inverse Methods in Physical Oceanography: Frontmatter , 1992 .

[6]  A. Bennett.  Inverse Methods in Physical Oceanography , 1992 .

[7]  A. Bennett,et al.  TOPEX/POSEIDON tides estimated using a global inverse model , 1994 .

[8]  L. Leslie,et al.  Generalized inversion of a global numerical weather prediction model , 1996 .

[9]  R. Hodur.  The Naval Research Laboratory’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) , 1997 .

[10]  R. Giering,et al.  Construction of the adjoint MIT ocean general circulation model and application to Atlantic heat transport sensitivity , 1999 .

[11]  Boon S. Chua,et al.  Generalized Inverse of a Reduced Gravity Primitive Equation Ocean Model and Tropical Atmosphere–Ocean Data , 2000 .

[12]  Paul J. Martin,et al.  Description of the Navy Coastal Ocean Model Version 1.0 , 2000 .

[13]  P. Courtier,et al.  Correlation modelling on the sphere using a generalized diffusion equation , 2001 .

[14]  Andrew F. Bennett,et al.  An inverse ocean modeling system , 2001 .

[15]  A. Bennett,et al.  Inverse Modeling of the Ocean and Atmosphere , 2002 .

[16]  John C. Kindle,et al.  High resolution modeling and data assimilation in the Monterey Bay area , 2002 .

[17]  Carl Wunsch,et al.  Global ocean circulation during 1992-1997, estimated from ocean observations and a general circulation model , 2002 .

[18]  D. Wurmser,et al.  Global Ocean Nowcasts and Forecasts with the Navy Coastal Ocean Model (NCOM) , 2003 .

[19]  Paul J. Martin,et al.  Global Ocean Nowcasts and Forecasts with the Navy Coastal Model (NCOM) , 2003 .

[20]  J. O'Brien,et al.  Export pathways for river discharged fresh water in the northern Gulf of Mexico , 2003 .

[21]  H. Ngodock,et al.  The Maintenance of Conservative Physical Laws within Data Assimilation Systems , 2003 .

[22]  Jérôme Vialard,et al.  Three- and Four-Dimensional Variational Assimilation with a General Circulation Model of the Tropical Pacific Ocean. Part I: Formulation, Internal Diagnostics, and Consistency Checks , 2003 .

[23]  Hernan G. Arango,et al.  A comprehensive ocean prediction and analysis system based on the tangent linear and adjoint of a regional ocean model , 2004 .

[24]  H. Hurlburt,et al.  Sea Surface Height Predictions from the Global Navy Coastal Ocean Model During 1998-2001 , 2004 .

[25]  H. Ngodock.  Efficient implementation of covariance multiplication for data assimilation with the representer method , 2005 .

[26]  Paul J. Martin,et al.  Formulation, implementation and examination of vertical coordinate choices in the Global Navy Coastal Ocean Model (NCOM) , 2006 .

[27]  Paul J. Martin,et al.  Validation of interannual simulations from the 1/8° global Navy Coastal Ocean Model (NCOM) , 2006 .

[28]  R. Signell,et al.  Two-way air-sea coupling : A study of the adriatic , 2006 .

[29]  C. Wunsch.  Discrete Inverse and State Estimation Problems: With Geophysical Fluid Applications , 2006 .

[30]  Paul J. Martin,et al.  Modeling of upwelling/relaxation events with the Navy Coastal Ocean Model , 2007 .

[31]  T. Özgökmen,et al.  A Lagrangian subgridscale model for particle transport improvement and application in the Adriatic Sea using the Navy Coastal Ocean Model , 2007 .

[32]  Martin Erwig,et al.  Parametric Fortran: program generation in scientific computing , 2007, J. Softw. Maintenance Res. Pract..

[33]  Julie Pullen,et al.  Bora event variability and the role of air‐sea feedback , 2007 .

[34]  Cycling the Representer Algorithm for Variational Data Assimilation with the Lorenz Attractor , 2007 .

[35]  Hernan G. Arango,et al.  Weak and strong constraint data assimilation in the inverse Regional Ocean Modeling System (ROMS): Development and application for a baroclinic coastal upwelling system , 2007 .

[36]  P. Martin,et al.  Vertical structure of bottom Ekman tidal flows: Observations, theory, and modeling from the northern Adriatic , 2009 .

[37]  N. Banas,et al.  Evaluation of a coastal ocean circulation model for the Columbia River plume in summer 2004 , 2009 .

[38]  P. Martin,et al.  Eddies and filaments of the Western Adriatic Current near Cape Gargano: Analysis and prediction , 2009 .

[39]  Andrew M. Moore,et al.  Application of 4D-Variational data assimilation to the California Current System , 2009 .

[40]  J. Kindle,et al.  Summary diagrams for coupled hydrodynamic-ecosystem model skill assessment , 2009 .

[41]  H. Ngodock,et al.  Cycling the Representer Method with Nonlinear Models , 2009 .

[42]  Paul J. Martin,et al.  Impact of glider data assimilation on the Monterey Bay model , 2009 .

[43]  David M. Fratantoni,et al.  Development, implementation and evaluation of a data-assimilative ocean forecasting system off the central California coast , 2009 .

[44]  Pierre F. J. Lermusiaux,et al.  Forecasting and Reanalysis in the Monterey Bay/California Current Region for the Autonomous Ocean Sampling Network-II Experiment , 2009 .

[45]  Michel Rixen,et al.  Relative dispersion in the Liguro-Provençal basin: From sub-mesoscale to mesoscale , 2011 .

[46]  C. Lemckert,et al.  Evaluation of met-ocean forecast data effectiveness for tracking drifters deployed during operational oil spill response in Australian waters , 2011 .

[47]  Qing Xu,et al.  SAR observation and model tracking of an oil spill event in coastal waters. , 2011, Marine pollution bulletin.

[48]  Mark A. Moline,et al.  Observed and modeled bio‐optical, bioluminescent, and physical properties during a coastal upwelling event in Monterey Bay, California , 2011 .

[49]  A. Moore,et al.  Corrections to ocean surface forcing in the California Current System using 4D variational data assimilation , 2011 .

[50]  H. Ngodock,et al.  A Weak Constraint 4D-Var Assimilation System for the Navy Coastal Ocean Model Using the Representer Method , 2013 .

[51]  H. Ngodock,et al.  A 4DVAR System for the Navy Coastal Ocean Model. Part 2: Strong and Weak Constraint Assimilation Experiments with Real Observations in Monterey Bay , 2014 .