Geoscience Reference
In-Depth Information
(a)
(b)
(c)
(d)
(e)
Figure 6.14. Fluorescence sensor deployment platforms.
(A)
CTD Rosette vertical profiler. Water
was pumped in series through a fluorometer and other environmental sensors, where instruments
were mounted at the bottom of the Rosette and CDOM fluorometer. (Courtesy of R. Conmy.)
(B)
Towed vehicle with various optical and chemical sensors. (Courtesy of R.F. Chen.)
(C)
Minishuttle
tow-yo vehicle deployed with chlorophyll and NOM fluorometers, dissolved oxygen sensor, and
CTD. (Courtesy of R.F. Chen.)
(D, E)
Buoys, moorings, and gliders are also platforms for optical and
environmental sensors. (Courtesy of Cefas.) (See Plate 10.)
available sensors (
Figure 6.14
). Vertical profilers allow for depth-dependent fluorescence
observations and the simultaneous collection of discrete water samples from Niskin bot-
tles. Towed vehicles have been successfully deployed to study FOM in estuaries and river
plumes and can operate either in undulating mode (computer-controlled wing determines
depth pattern) or in tow-yo mode (wire out controls depth). These systems can also pump
water from the platform surface through tubing to the deck of a boat for discrete bottle
sampling (Chen and Gardner,
2004
). Towed systems offer the added benefit of observations
made in both the horizontal and the vertical directions, creating cross-sectional distribu-
tions of measurements.
AUVs and gliders can house the smallest fluorometers and allow autonomous deploy-
ment of instruments with preprogrammed missions or adjustable missions when the AUV
surfaces, and AUVs and gliders have been used to survey coastal areas without ship sup-
port. Advantages include greater spatial coverage, the potential for use of a fleet of AUVs to
obtain three-dimensional distributions and deployment in rough sea states. Disadvantages
