142
resolving small-scale variations within convoluted coastlines and for reducing the
computational load. Choice and tuning of subgrid parameterization schemes must
accurately reflect known local conditions. Data assimilation schemes will vary
depending on the volume and quality of real-time data available. Given the high
density of satellite data, subsampling for model assimilation is necessary to reduce
the computational load while reflecting the full range of the variable of interest.
Similarly to color-coded depiction of satellite data, lower and upper data range
boundaries are chosen to reflect known natural local variability so as to produce
informative graphics with high information content. If time series graphs of model
output for specific locations is contemplated (virtual buoys), numerical procedures
for data extraction at these points must be implemented. Further detail regarding
model implementation may be found in Chap. 6 of this book.
8.3 Deployment and Maintenance of Ocean Observing
Platforms in the Coastal Zone
The wide range of mobile and fixed platforms now available for ocean observing
requires specialized skills and equipment for each task. Significant expense may be
incurred in platform deployment, maintenance, and retrieval. Three examples, those
of coastal buoys, HF radar, and gliders, are discussed below.
8.3.1 Buoy Deployment and Maintenance
Design of instrument-bearing buoy systems is discussed elsewhere in this book
(Chap. 3, Sect. 3.2). Information regarding buoy system design and engineering has
been compiled by Snyder (1969). Intermediate size coastal ODAS buoys require
heavy mooring anchors with weight in excess of the buoy displacement weight
(around one metric ton) by at least 30%. Transportation and deployment of such
buoys is preferentially accomplished aboard specialized buoy-tending vessel
equipped with purpose-designed buoy handling gear and low freeboard mid sections or stern ramps to facilitate operations. In their absence, oceanographic vessels
or other vessels or barges equipped with heavy lifting gear may be used. When
deployed from a vessel, the buoy is released first. Once adrift, the mooring tackle is
paid out as the vessel progresses away from the buoy. The anchor is weighed off
deck and released into the water at the designated station before the final lengths of
tackle are paid out (Fig. 8.2).
An alternate means of buoy system deployment is for anchor and mooring line to
be floated at dockside using heavy-duty pneumatic lifting bags. Dockside cranes
facilitate transfer of buoy and mooring tackle to the water. The entire buoy system
may be then towed to the deployment site. Exact buoy deployment site is recorded
at the time of anchor release.
8 Planning, Implementation, and Operation of Coastal Ocean Observing Systems
resolving small-scale variations within convoluted coastlines and for reducing the
computational load. Choice and tuning of subgrid parameterization schemes must
accurately reflect known local conditions. Data assimilation schemes will vary
depending on the volume and quality of real-time data available. Given the high
density of satellite data, subsampling for model assimilation is necessary to reduce
the computational load while reflecting the full range of the variable of interest.
Similarly to color-coded depiction of satellite data, lower and upper data range
boundaries are chosen to reflect known natural local variability so as to produce
informative graphics with high information content. If time series graphs of model
output for specific locations is contemplated (virtual buoys), numerical procedures
for data extraction at these points must be implemented. Further detail regarding
model implementation may be found in Chap. 6 of this book.
8.3 Deployment and Maintenance of Ocean Observing
Platforms in the Coastal Zone
The wide range of mobile and fixed platforms now available for ocean observing
requires specialized skills and equipment for each task. Significant expense may be
incurred in platform deployment, maintenance, and retrieval. Three examples, those
of coastal buoys, HF radar, and gliders, are discussed below.
8.3.1 Buoy Deployment and Maintenance
Design of instrument-bearing buoy systems is discussed elsewhere in this book
(Chap. 3, Sect. 3.2). Information regarding buoy system design and engineering has
been compiled by Snyder (1969). Intermediate size coastal ODAS buoys require
heavy mooring anchors with weight in excess of the buoy displacement weight
(around one metric ton) by at least 30%. Transportation and deployment of such
buoys is preferentially accomplished aboard specialized buoy-tending vessel
equipped with purpose-designed buoy handling gear and low freeboard mid sections or stern ramps to facilitate operations. In their absence, oceanographic vessels
or other vessels or barges equipped with heavy lifting gear may be used. When
deployed from a vessel, the buoy is released first. Once adrift, the mooring tackle is
paid out as the vessel progresses away from the buoy. The anchor is weighed off
deck and released into the water at the designated station before the final lengths of
tackle are paid out (Fig. 8.2).
An alternate means of buoy system deployment is for anchor and mooring line to
be floated at dockside using heavy-duty pneumatic lifting bags. Dockside cranes
facilitate transfer of buoy and mooring tackle to the water. The entire buoy system
may be then towed to the deployment site. Exact buoy deployment site is recorded
at the time of anchor release.
8 Planning, Implementation, and Operation of Coastal Ocean Observing Systems