Long-Term Data

Washington State Department of Ecology

MARINE WATERS HOME

Water Column

Tidal Effects

DATA

RELATED ECOLOGY PROGRAMS

Marine Flights:	Data 1973 to 1989	Data 1999 - present	Anomalies 1999 - present
Moorings:	Current real time data	Historic data and sites
Ferry:	En route ferry data

Data Quality

High data quality is mandatory for Ecology's Long-Term Monitoring Program and ensures that trends accurately reflect true environmental change. We routinely perform data quality assurance (QA), data quality controls (QC) and data group reviews to ensure that our data meet highest quality standards. Data quality codes are applied to the dataset allowing you to decide the appropriate level of quality for your analysis. Detailed information on data quality can be found at:

Data quality codes

A. Marine Flight Data (Download)

Marine flight data serve as Ecology's backbone to determine long-term trends and patterns in water quality related to eutrophication estuarine processes. Sensors are subjected to strict performance test prior to flights. We use a Sea-Bird CTD package equipped with sensors for vertical water column profiles and Niskin bottles for collecting water samples at pre-assigned depth.

Continuous vertical profiles- We conduct pre-flight performance tests and take intermittent sensor performance samples during flights.
Discrete water samples - To ensure highest analytical quality, we include blank and control samples of known concentration in our data stream.
Data collected prior to 1990 is available on request.

For marine flight data both accuracy and precision are known at all times. The high data quality allows us to determine longterm shifts in water quality baseline conditions. Flight data also help to calibrate marine in situ sensors maintained by Ecology and its partners. A limited temporal resolution precludes us from detecting a change in the frequency, amplitude and duration of events that also can affect water quality.

B. Mooring and Ferry Data (Victoria Clipper)

In situ sensors mounted to permanent moorings or moving ferries offer high precision and excellent temporal resolution. The advantages of the approach is to measure processes to complement our long- term marine flight program. In situ sensors are, however, exposed to the marine environment for long time periods and a systematic drift over time is inevitable (cause for a systematic bias and changing accuracy). Mooring and ferry data can be harvested with different level of data quality. A drift adjustment of sensor data can be done typically at the end of a deployment cycle in our database. We therefore offer:

Real-time data (Download) - a coarse and automated quality control ensures that sensor are not reporting outside natural ranges.
Archived data (Download) - a refined data review and data drift adjustment removes data issues. Data quality codes inform about data issues. (drift is assumed to be linear and accuracy can only be approximated over the deployment period)
En route ferry data (Link to data and information)

In situ sensors offer a unique insight into environmental processes and complement our long-term marine monitoring flight programs. Their strength reside in quantifying the dynamic of patterns with high temporal variability such as tides, oceanic low-oxygen intrusions and storms. Both flight and mooring data need to be evaluated side by side as part of a larger marine monitoring effort. We share our information with our marine monitoring partners for an improved understanding of our marine environment.