Tamar Estuary
Time Series…
The Saltash pontoon sits at site C15 in around 4m of water, measurements were taken
between every 30 minutes and every hour during the day to produce a time series.
Three procedures were followed-
INTRODUCTION
The graphs from this time series data show several main area of interest. Sampling
began at 08:30am (UTC). At this time, flow speed began to decrease causing salinity
to increase in all water levels as high tide approached. Current speed dropped to
a minimum at high tide (09:56 UTC) causing a salinity peak in all layers of water.
After this peak, salinity decreases as the tide goes out and more fresh water flows
past the pontoon. In addition to this, in the surface layer, the temperature peaked
at 24°C-
After high water, the direction of the current changes and stays constant throughout
the afternoon. The current speed increases in the surface layer up to a maximum of
around 0.8ms-
Temperature in the top 1m of the water column peaks just after midday, accompanied by a drop in salinity in the surface waters. This suggests increased stratification as a warm, fresh layer of water sits on top of the main estuary water. Current speed peaks at 1pm and then begins to fall as low tide approaches (15:50pm).
FINDINGS
21. Pontoon time series data of flow speed against time (UTC) collected on 05/07/18.
22. Time series of salinity as sampled from the pontoon at Saltash on 05/07/18.
23. Time series of salinity as sampled from the pontoon at Saltash on 05/07/18.
24. Pontoon time series data of flow direction (°) against time (UTC) collected on 05/07/18.
25. Time series of O2 saturation as sampled from the pontoon at Saltash on 05/07/18.