sea_surface_primary_swell_wave_from_direction

The quantity with standard name sea_surface_primary_swell_wave_from_direction is the direction from which the most energetic swell waves are coming. Swell waves are waves on the ocean surface and are the low frequency portion of a bimodal wave frequency spectrum. The primary swell wave is the most energetic swell wave. The phrase "from_direction" is used in the construction X_from_direction and indicates the direction from which the velocity vector of X is coming. The direction is a bearing in the usual geographical sense, measured positive clockwise from due north. rdf:langString