Nearshore Canyon Experiment (NCEX)
The NCEX has been designed to determine the effects of submarine canyons and other complex seafloor formations on waves and currents.
As waves pass over the canyons, the steep topography can act like a magnifying glass and concentrate ocean wave energy in “hot spots” where waves are large. Alongshore variation of waves and currents can result in rip currents. Increased understanding of nearshore waves and currents, including “hot spots”, can be used to improve beach management and public safety.
At the core of the experiment, scientists have collected field measurements to test and verify numerical models of how the underwater canyons affect the coastal processes.
The NCEX has made use of extensive arrays of instruments to measure waves, currents, and sand levels in and around the submarine canyons. Among these instruments were buoys, sea-surface drifters, radar, sonar, video cameras, WaveRunners, all terrain vehicles, airplanes, and Nortek Vector current meters as well as Nortek Aquadopp current profilers.
Instruments located in depths of 2.5m or shallower, including 4 2D/3D Vectors, were cabled to small shore stations or trailers on the beach. Instruments in deeper water store data on internal recording systems or use wireless technology to transmit data to shore.
Before the research team decided which current meters to use, several types from different manufacturers were tested and the Vector and the Aquadopp Profilers ended up among the preferred ones. There were a number of reasons for this. Both the Vectors and the Aquadopps are fairly inexpensive and very well-suited for stand-alone deployments with their built-in high capacity non-volatile internal recording systems. They are known for their low noise and their data acquisition reliability.
Data is sampled at 1Hz, which gives the Vector plenty of time to make averages, thereby providing data with a very good signal-to-noise ratio.
The moorings used were made up of two basic types, which were deployed in different ways. The first mooring type used a surface float attached to the platform via a polypro line. The second mooring type had no surface float and was mounted on the bottom.