Observed and Simulated Surface Wave and Roller Dissipation with Ground Truth Data at the West Coast of Sylt on Sep 27 - Oct 2, 2016

This dataset contains post-processed Doppler marine radar observations and numerical simulations of surface wave and roller dissipation as well as wave energy flux across the surf zone of a double-barred sandy beach at the island of Sylt, Germany.

The methodology to obtain dissipation from coherent marine radar data is described in the following article:

Streßer, M., Horstmann J., Baschek, B. (2022): Surface Wave and Roller Dissipation Observed with Shore-based Doppler Marine Radar. Manuscript in preparation.

The simulations were realized with with the SimpleWaves1D model using the Janssen and Battjes (2007)  wave breaking parameterization. The wave buoy data used to force the model was recorded as part of the COSYNA observation system. The bathymetry transect was generated using the echosounder data of Cysewski et al. (2019)

Radar data and and simulation results are re-gridded to a common hourly time grid using nearest neighbor interpolation with the dimension [time x range].

Structure of radar observations:

CMRgridded = 

  struct with fields:

               t: [109×1 double]     time as Matlab datenum
               r: [435×1 double]     range, i.e. distance from radar antenna [m]
              cg: [435×109 double]   wave group velocity [m/s]
              cp: [435×109 double]   wave phase velocity [m/s]
               d: [435×109 double]   local water depth [m]
    H_rms_roller: [435×109 double]   energy wave height estimated using the roller concept [m]
               k: [435×109 double]   local wave number [rad/m]
               w: [435×109 double]   wave frequency [rad/s] 
              Dr: [435×109 double]   roller dissipation [W/m^2]
              Er: [435×109 double]   roller energy [Nm/m^2]
              Fr: [435×109 double]   flux of roller energy [W/m] 
              Dw: [435×109 double]   wave dissipation [W/m^2]

Structure of the simulation results:

SWgridded = 

  struct with fields:

        t: [109×1 double]     timestamp as Matlab datenum 
        r: [435×1 double]     range, i.e. distance from radar antenna [m]
       cg: [435×109 double]   wave group velocity [m/s]
       cp: [435×109 double]   wave phase velocity [m/s]
        d: [435×109 double]   local water depth [m]
    H_rms: [435×109 double]   energy wave height [m]
        E: [435×109 double]   wave energy [Nm/m^2]
       Dr: [435×109 double]   roller dissipation [W/m^2]
       Dw: [435×109 double]   wave dissipation [W/m^2]
       Er: [435×109 double]   roller energy [Nm/m^2]
       Qb: [435×109 double]   fraction of breaking waves [-]

Ground truth data is available from two bottom mounted pressure wave gauges (PG) located at r=127.5 m (PG_A) and r=180 m (PG_B)  and a wave rider buoy located at r=1100 m. 

Structure of the ground truth data;

PG = 

  struct with fields:

          t: [209×1 double]  timestamp as Matlab datenum
    Hs_pg_A: [209×1 double]  significant wave height at the pressure gauge A
    Hs_pg_B: [209×1 double]  significant wave height at the pressure gauge B


WR = 

  struct with fields:

         t: [1344×1 double]   timestamp as Matlab datenum
        Hs: [1344×1 double]   significant wave height [m]
      Dirp: [1344×1 double]   wave direction at the peak frequency [°]
        Tp: [1344×1 double]   peak period [s]
     Tmean: [1344×1 double]   mean period, or Tm(0,1) [s]
    Tcross: [1344×1 double]   zero-upcross period [s]
      Sprp: [1344×1 double]   directional spread at the peak frequency [°]
    

The data is stored in Matlab^® v7.3 format. Timestamps are given as Matlab^® datenum, i.e. whole and fractional number of days from January 0, 0000.