you are here: / home / projects / East Sound '98 / instrumentation
Thin Layers Experiment, East Sound, Orcas Island, Washington
Interactions between Small-Scale Physical, Optical and Biological Processes

[ Introduction ] [ Project Goals ] [ Approach ] [ Instrumentation ] [ Results ]

Instrumentation

The SlowDROP vertical profiling system was configured to provide centimeter-scale resolution of several physical and bio-optical parameters. The profiler was equipped with several floats in order to provide near-neutral buoyancy during free-fall profiling. Thus, the SlowDROP profiler sank at a very slow descent rate (approximately 10-20 cm per second). All of the intakes or sensors for the instruments included with the SlowDROP were located at the base of the profiler.

The SlowDROP instrumentation package was powered by the SMODAPS data acquisition system from WETLabs, Inc., shown at the left. SMODAPS provided a single power source for, and an integrated data stream from all the instruments deployed on the profiler with a unique time stamp on each data packet from the instruments. This allowed for the accurate merging of all the data sets from the profiler. The instrumentation suite on the SlowDROP profiler during the East Sound, 1998 field study consisted of the following:

• Sea-Bird Electronics, Inc., Model 9 CTD measuring conductivity, temperature, pressure and oxygen.

• Two WETLabs, Inc., AC-9's measuring the absorption and attenuation spectra at 9 wavelengths from particulate matter (e.g. detritus and phytoplankton) and colored dissolved organic matter by fitting the intake of one of the AC-9's with a 0.2 micron filter.

• Two SAFIRE multi-excitation spectral fluorometer from WETLabs, Inc., measuring the fluorescence emission spectra of dissolved and particulate matter using 6 excitation wavelengths from 212 to 487 nm and 16 emission wavelengths from 265 to 680 nm. For certain periods of the field study, one of the SAFIRE's was fitted with 0.2 micron filter at the intake to measure dissolved matter only.

• Single-channel fluorometer, FlashPak, measuring chlorophyll fluorescence from WETLabs, Inc.

• SonTek, Inc., Acoustic Doppler Velocimeter (ADV), configured to obtain horizontal velocity shear on 10 cm vertical scales.

• Sea-Bird Electronics, Inc., Model 32 Carousel Water Sampler with 12 500 mL niskin bottles from Ocean Test Equipment, Inc.

Concurrent with SlowDROP deployments off the R/V Henderson, we deployed thermistor chains (see the thermistor chain page) to measure physical forcing through internal wave field energy.

In addition, we deployed a tethered radiometric buoy to monitor spectral upwelling radiance and downwelling irradiance over the course of a day.

The Bio-Optics site was created by, and is maintained by Christopher E. Wingard.
Questions, comments or criticisms? cwingard_at_coas_dot_oregonstate_dot_edu.
This page was last updated on 10-Nov-2005 using 100% post-consumer recycled photons.

Unless otherwise explicitly stated, all of the information and images presented in this web site are copyrighted © by Oregon State University, College of Oceanic and Atmospheric Sciences. Please refer to the Oregon State University Disclaimer and the Copyright Center for more information.