. "SDN:P07::CFSN0380" . . "2" . "sea_surface_swell_wave_zero_upcrossing_period"@en . "2" . "true" . . "2017-03-27 15:08:35.0" . . . "2017-03-27 15:08:35.0" . . "A period is an interval of time, or the time-period of an oscillation. The zero upcrossing period is defined as the time interval between consecutive occasions on which the surface height passes upward above the mean level. Swell waves are waves on the ocean surface."@en . . . . "SDN:P07::CFSN0380" . . "SDN:P07::CFSN0380" . . . . "deprecated"@en . . . "" .