anchor.diff:  
     call model_run(h, u, v, eta, depth, dx, dy, wetmask, fu, fv, &
         dt, au, ar, botDrag, ah, slip, hmin, nTimeSteps, dumpFreq, avFreq, &
  -      maxits, eps, freesurfFac, thickness_error, debug_level, g_vec, rho0, &
  +      checkpointFreq, maxits, eps, freesurfFac, thickness_error, &
  +      debug_level, g_vec, rho0, &
         base_wind_x, base_wind_y, wind_mag_time_series, &
         spongeHTimeScale, spongeUTimeScale, spongeVTimeScale, &
         spongeH, spongeU, spongeV, &
  
positive.code: 
  subroutine model_run(h, u, v, eta, depth, dx, dy, wetmask, fu, fv, &
      dt, au, ar, botDrag, ah, slip, hmin, nTimeSteps, dumpFreq, avFreq, &
      maxits, eps, freesurfFac, thickness_error, debug_level, g_vec, rho0, &
      base_wind_x, base_wind_y, wind_mag_time_series, &
      spongeHTimeScale, spongeUTimeScale, spongeVTimeScale, &
      spongeH, spongeU, spongeV, &
  
negative.code:         dudt, dvdt, dhdt, &
          wind_x, wind_y, nx, ny, layers, &
          n, nwrite, avwrite, RedGrav, DumpWind, debug_level)
  
      ! save a checkpoint?
  
  
      cur_time = time()
      if (cur_time - last_report_time > 3) then
  