Surf’s up… down deep

Surf’s up… down deep

Surf’s up… down deep

Internal waves generated by tidal motions are the dark and silent type. Termed the internal tide, these waves heave the deep water up and down great distances; yet they show only slight excursions at the surface. They travel long distances underwater, yet little is known about their termination. En route, these internal waves exhibit strong currents.

In early 2015, scientists from several countries studied this type of internal wave in the Tasman Sea. One group searched for the pathway of the internal tide during its trans-oceanic passage. Among other tools, they relied on data from ship-mounted and lowered Teledyne RDI ADCPs (L-ADCP). For selecting their observational site, the scientists considered results from computer models and satellite altimeters.

ADCPs Help to Reveal Trans-Tasman Pathway of Internal Tide ADCPs Help to Reveal Trans-Tasman Pathway of Internal Tide

Surf’s up... down deep
Lowered ADCP (L-ADCP) is attached to a package that is routinely lowered to take water samples and to measure temperature and salinity. Careful processing corrects for the motions of the lowered package and the ship are required.