Hyperspectral Coupled Ocean Dynamics Experiments (HyCODE)

This portion of the HyCode program provides an observational study of the roles of vertical turbulent mixing and coastal upwelling in transporting suspended sediments to optically relevant heights in optically deep water. The study will capitalize on recent development of field instruments, termed Laser In Situ Sizing and Transmissometry (LISST) sensors, which provide optical measurements of the particle size spectrum in the diameter range between approximately 1 and 250 microns. Supporting instrumentation will include an array of fluorometers, which will permit at least a crude distinction between suspended sediments and particles containing chlorophyll; an array of temperature sensors, which will provide measurements of stratification; and an array of velocity sensors, which will determine flow conditions. The tripods were deployed on July 24, 2000, near the NODE B at the LEO-15 site off central New Jersey at approximately 15 meters depth. Data were continuously logged through September 21, spanning the coastal upwelling season and extending into atmospheric cooling and wind forcing events of the early fall. The large tripod was redeployed on September 16 and the final recovery was on December 2, 2000.
 

                                                    Trowbridge Tripod                                             Agrawal Tripod
Deployment I:                         7/24/00 - 9/15/00                                              7/24/00 - 9/13/00
                                                      39° 27.39´ N                                                          39° 27.40´ N
                                                      74° 14.31´ W                                                         74° 14.24´ W

Deployment II:                       9/16/00 - 12/2/00                                             10/11/00 - 12/2/00
                                                    39° 27.31´ N                                                             39° 27.39´ N
                                                    74° 14.32´ W                                                             74° 14.22´ W

A large footprint tripod was instrumented with two Sontek ADV velocity sensors, which were designed to simultaneously sample temperature nearly colocated with the velocity sampling volume. The configuration of the two probes was designed to provide a means to remove waves from the velocity measurements to provide direct estimates of stress. The Sontek ADVs also provide signal strength, which will be used as a proxy to sediment concentration to estimate < c ´ w ´ >. The instruments measure horizontal and vertical velocity, signal strength and temperature at approximately 0.7 and 3.4 mab, sampling for approximately a half-hour of each hour at 5 Hz throughout the deployments. A Seaguage also was placed on the tripod to obtain salinity, temperature and pressure.

Figure 1.   The schematic shows the ADVs at 0.7 and 3.4 mab. YSI thermistors are strapped to each ADV, as well as on the platform, near the Seagauge wave and tide recorder.

Another tripod samples similarly and will be equipped with an array of LISST sensors, including a LISST-ST, providing settling velocity, and a MSCAT, providing particle size within 10 cm of the bottom.

Last Update: Tue Jan 30 12:35:40 2000.