wavespectra.partition.partition.Partition.ptm1

Partition.ptm1(wspd, wdir, dpt, agefac=1.7, wscut=0.3333, swells=3, smooth=False, freq_window=3, dir_window=3, ihmax=100)

PTM1 watershed partitioning.

In PTM1, topographic partitions for which the percentage of wind-sea energy exceeds a defined fraction are aggregated and assigned to the wind-sea component (e.g., the first partition). The remaining partitions are assigned as swell components in order of decreasing wave height.

Args:

• wspd (xr.DataArray): Wind speed DataArray.

• wdir (xr.DataArray): Wind direction DataArray.

• dpt (xr.DataArray): Depth DataArray.

• swells (int): Number of swell partitions to compute.

• agefac (float): Age factor.

• wscut (float): Wind sea fraction cutoff.

• smooth (bool): Compute watershed boundaries from smoothed spectra as described in Portilla et al., 2009.

• freq_window (int): Size of running window for smoothing spectra.

• dir_window (int): Size of running window for smoothing spectra.

• ihmax (int): Number of discrete spectral levels in WW3 Watershed code.

Returns:

• dspart (xr.Dataset): Partitioned spectra with extra part dimension where the 0th index are the wind sea and remaining indices are the swells sorted by descending order of Hs.

References:

• Hanson and Phillips (2001).

• Hanson et al. (2009).

• Portilla et al. (2009).

• Tracy et al. (2007).

• Vincent et al. (1991).

• WW3 documentation (NOAA-EMC/WW3).