Falmouth Group 8

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Station 4

The range in transmissivity values was 4.09-4.21, with ranges at specific depths up to around 0.05. The average surface value was approximately 4.12, and there is a general positive linear change from then on, ending at an average value of approximately 4.20.

Transmissivity-Figure 3

The vertical profile observed at station 4 (50° 12.126N, 005° 02.456W) shows an almost perfect expected nutrient distribution. Salinity is uniform at 34.2 for the first 6.0m, then increases to a high of 34.7 at 12.9m. Nitrate, phosphate and silicon values follow almost identical trends, falling from 5.75 mmol/L, 1.93x10-3mmol/L and 3.30mmol/L at 1.2m to 4.54mmol/L, 1.39x10-3mmol/L and 2.50mmol/L at 6m respectively. The decline in these levels then follows a steeper gradient to 12.96m where a nitrate value of 4.14mmol/L, a silicon value of 1.85mmol/L and a phosphate value of 1.14x10-3mmol/L are observed.
   It in interesting to note that any major changes observed in these vertical profiles occur 5m above the estimated 1% irradiance depth calculated, and not within its vicinity as would be expected.

Nutrients-Figure 2

Fluorescence-Figure 1

Error Range: 0.466-0.407 = 0.059 taken at 5.8 meters.

Fluorescence increases from an average of 0.384 at 1.2m to 0.438 at 5.7m. Between 6 and 9m fluorescence shows a slight decrease of 0.009. At 10 meters the average fluorescence increases to 0.464 and continues to increase to 12.9m where the average fluorescence is 0.485.

ADCP Transect-Figures 4,5&6

Because of the shallower depth range sampled here, backscatter shows a pattern of maximum readings occurring at the surface layer: up to over 91 dB. Minimum readings of around 70 dB occur at the deepest depth of approximately 14 m.

With regards to north velocity, the tidal flow at the surface layer of the estuary was proceeding outwards in a southerly direction at -0.5 m/s. The bottom layer of the estuary meanwhile was flowing inwards in a northerly direction at 0.5 m/s.

From the ship track it can be observed that the flow velocity is stronger around the surface layer (2.66 m) than the flow velocity at 12.26 m depth.

Click graphs to enlarge

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