Data assimilation of partitioned HF radar wave data into Wavewatch III

In this study the assimilation of HF radar data into a high resolution, coastal Wavewatch III model is investigated. An optimal interpolation scheme is used to assimilate the data and the design of a background error covariance matrix which reflects the local conditions and difficulties associated with a coastal domain is discussed. Two assimilation schemes are trialled; a scheme which assimilates mean parameters from the HF radar data and a scheme which assimilates partitioned spectral HF radar data. This study demonstrates the feasibility of assimilating partitioned wave data into a coastal domain. The results show that the assimilation schemes provide satisfactory improvements to significant wave heights but more mixed results for mean periods. The best improvements are seen during a stormy period with turning winds. During this period the model is deficient at capturing the change in wave directions and the peak in the waveheights, while the high sea state ensures good quality HF radar data for assimilation. The study also suggests that there are both physical and practical advantages to assimilating partitioned wave data compared to assimilating mean parameters for the whole spectrum.

[1]  Hendrik L. Tolman,et al.  Source Terms in a Third-Generation Wind Wave Model , 1996 .

[2]  Piero Lionello,et al.  An optimal interpolation scheme for the assimilation of spectral wave data , 1997 .

[3]  J. Cummings,et al.  Assimilation of Altimeter Wave Measurements into Wavewatch III , 2005 .

[4]  R. Stratton,et al.  Some experiments to investigate the assimilation of SEASAT altimeter wave height data into a global wave model , 1990 .

[5]  L. Gandin.  Objective Analysis of Meteorological Fields , 1963 .

[6]  N. Booij,et al.  A third‐generation wave model for coastal regions: 2. Verification , 1999 .

[7]  Lucy R. Wyatt,et al.  Assimilation of HF radar data into the SWAN wave model , 2009 .

[8]  David R. Jackson,et al.  Use of Canadian Quick covariances in the Met Office data assimilation system , 2008 .

[9]  Dinorah C. Esteva,et al.  Evaluation of preliminary experiments assimilating Seasat significant wave heights into a spectral wave model , 1988 .

[11]  Vladan Babovic,et al.  Wave data assimilation using ensemble error covariances for operational wave forecast , 2006 .

[12]  J. Howarth,et al.  Operational Wave, Current, and Wind Measurements With the Pisces HF Radar , 2006, IEEE Journal of Oceanic Engineering.

[13]  P. Heimbach,et al.  An improved algorithm for the retrieval of ocean wave spectra from synthetic aperture radar image spectra , 1996 .

[14]  M. W. Holt,et al.  Preliminary Assessment and Use of ERS-1 Altimeter Wave Data , 1994 .

[15]  I. Young,et al.  Forecast Divergences of a Global Wave Model , 2005 .

[16]  S. Hasselmann,et al.  Assimilation of wave spectra from pitch-and-roll buoys , 1997 .

[17]  T. Barnett,et al.  Measurements of wind-wave growth and swell decay during the Joint North Sea Wave Project (JONSWAP) , 1973 .

[18]  Hans C. Graber,et al.  Validation and assimilation of Seasat altimeter wave heights using the WAM wave model , 1992 .

[19]  Jeffrey L. Hanson,et al.  Automated Analysis of Ocean Surface Directional Wave Spectra , 2001 .

[20]  David W. Tarasick,et al.  Data assimilation with the Canadian middle atmosphere model , 2001 .

[21]  Lucy R. Wyatt,et al.  Ocean wave parameter measurement using a dual-radar system A simulation study , 1987 .

[22]  S. A. Sannasiraj,et al.  Optimal interpolation of buoy data into a deterministic wind–wave model , 2009 .

[23]  J. P. Thomas,et al.  Retrieval of energy spectra from measured data for assimilation into a wave model , 2006 .

[24]  Piero Lionello,et al.  Assimilation of altimeter data in a global third-generation wave model , 1992 .

[25]  Luigi Cavaleri,et al.  Wave Modeling—Missing the Peaks , 2009 .

[26]  N. Booij,et al.  A third-generation wave model for coastal regions-1 , 1999 .

[27]  S. Hasselmann,et al.  Computations and Parameterizations of the Nonlinear Energy Transfer in a Gravity-Wave Spectrum. Part I: A New Method for Efficient Computations of the Exact Nonlinear Transfer Integral , 1985 .

[28]  J. Bidlot,et al.  User manual and system documentation of WAVEWATCH III R version 4.18 , 2014 .

[29]  John Derber,et al.  The National Meteorological Center's spectral-statistical interpolation analysis system , 1992 .