Wave Hindcast Variables¶

Variables available in the U.S. WPTO wave hindcast. Each variable is requested by its Hindcast Variable Id, and maps directly to a SWAN model "bulk parameter".

Variables¶

Name	SWAN Name	Symbol	Units	Hindcast Variable Id	Description
Significant Wave Height	`HSIGN`	\(H_{m_0}\)	meters	`significant_wave_height`	Significant wave height
Energy Period	`TMM10`	\(T_e\), \(T_{-10}\)	seconds	`energy_period`	Energy period
Omni-Directional Wave Power		\(J\)	watts per meter	`omni-directional_wave_power`	Omnidirectional wave power
Mean Wave Direction	`DIR`		degrees clockwise from true north	`mean_wave_direction`	Mean wave direction
Peak Period	`RTP`	\(T_p\)	seconds	`peak_period`	Relative peak period of the variance density spectrum (in the absence of currents)
Maximum Energy Direction		\(\theta_J\)	degrees clockwise from true north	`maximum_energy_direction`	Direction of maximum wave energy
Directionality Coefficient		\(d\)	unitless, range from 0 to 1	`directionality_coefficient`	Directionality coefficient
Spectral Width		\(\epsilon_0\)	unitless, range from 0 to 1	`spectral_width`	Spectral width

Symbols

Symbols follow IEC 62600-101, which the standard refers to as "parameters".

Additional Variables¶

Name	SWAN Name	Symbol	Units	Hindcast Variable Id	Description
Mean Period	`PER`		seconds	`mean_average_period`	Mean absolute wave period, equivalent to \(T_{m_{01}}\)
Mean Absolute Zero Crossing Period	`TM02`	\(T_z\), \(T_{02}\)	seconds	`mean_zero_crossing_period`	Mean absolute zero crossing period
Peak Wave Direction	`PDIR`		degrees clockwise from true north	`peak_wave_direction`	Peak wave direction, determined by wave power

Metadata¶

Each point carries an associated metadata entry in the hindcast data that identifies non time-varying values.

Name	SWAN Name	Symbol	Units	Hindcast Variable Id
X Coordinate	`XP`		decimal degrees longitude	`longitude`
Y Coordinate	`YP`		decimal degrees latitude	`latitude`
Depth	`DEPTH`	\(h\)	meters	`depth`

Coming Soon

Per-variable documentation, including equations, valid ranges, and usage guidance, is under development.