Marine Data Products

Citizen Monitoring
Profiles
Time Series

ORCA Buoy
Profiles
Time Series

MMP Profiler + ADCP

Historical Comparisons

Comparative Cross-Sections

Freshwater & Terrestrial Data Products

Freshwater Sampling

Land Use

Geology

Marine Life Studies

Diver Observations

Bloom & Fish Kill Observations

Data Access

The Oceanic Remote Chemical-optical Analyzer (ORCA) is an autonomous water quality monitoring buoy developed by the University of Washington. For information on ORCA, its development and past history see:

http://www.ocean.washington.edu/research/orca/

Under the HCDOP-IAM study, five ORCA moorings will be deployed in Hood Canal. ORCAs are currently near Twanoh, Hoodsport, Duckabush, and North of the Hood Canal bridge.

Currently, ORCA measures the physical parameters of temperature (degrees C) and salinity to obtain density (presented here in sigma-t units).  The density of seawater is affected by both temperature and salinity; decreases in temperature and increases in salinity both cause density to increase.  The combination of these changes produces density stratification.

ORCA also measures the biological parameters of dissolved oxygen (umol/kg), phytoplankton chlorophyll fluorescence (ug/l), and particle attenuation (the inverse of water clarity - shown here as water cloudiness in absorbance - inverse meters - relative to the minimum value).  The chemical and biological parameters can have complex variability. Oxygen is often supersaturated in the surface as phytoplankton photosynthesize but can decrease dramatically subsurface as organic material is respired.