Texas Automated Buoy System (TABS): A Public Resource
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From Proceedings of the Oceanology International 98 Exhibition and Conference, 10-13 March
1998, Brighton UK, Vol. 1, pp. 103-112. For information about the conference see
www.spearhead.co.uk.
Texas Automated Buoy System (TABS): A Public Resource
F. J. Kelly, Norman L. Guinasso, Jr., Linwood L. Lee III
Geochemical and Environmental Research Group, College of Geosciences,
Texas A&M University, 727 Graham Road, College Station, Texas 77845 USA
G. F. Chaplin, Bruce A. Magnell
Woods Hole Group/Advanced Coastal Environmental Systems, 81 Technology Park Drive,
Falmouth, MA 02541 USA
Robert D. Martin, Jr.
Texas General Land Office, Oil-Spill Prevention and Response Division,
1700 N. Congress Ave., Austin, TX 78701, USA
ABSTRACT
In August, 1994, The State of Texas General Land Office (GLO) directed the Geochemical and
Environmental Research Group (GERG) of Texas A&M University to implement a program that provides
real-time observations of surface currents and water temperature at selected locations along the Texas
coast. The Texas Automated Buoy System (TABS) became operational in April 1995. Initially, the GLO
funded five buoy sites: two off Galveston, two off Port Aransas, and one near Sabine Pass. In 1997 it
authorized two additional TABS buoys for the region off Brownsville. TABS is a long-term operational
system that the GLO considers absolutely critical to its ability to predict where spilled oil will go in Texas
waters. Indeed, TABS data have proved pivotal during several recent spill responses. Beyond mandating
this primary mission, the GLO has taken three steps to form TABS into an effective public resource: it
insists that all TABS data be immediately disseminated through a user-friendly Internet webpage; it
supports research to improve the reliability, operational range, and versatility of the TABS buoys; and it
encourages other scientific research projects to build on the TABS resources.
TABS buoys take five-minute vector averages of current velocity and water temperature two
meters below the surface every thirty minutes. A shore-based computer at GERG automatically acquires
the data via cellular or satellite telephone four or more times per day, performs QA/QC functions, and
adds the observations to the TABS database, which is publicly available through an interactive Web site
http://www.gerg.tamu.edu/Tglo/. The buoys’ observations are viewed hundreds of times each day by
boaters, commercial fishing vessels, lightering operations, students, government agencies, and petroleum
companies. The accessibility of TABS data and the GLO’s long-term commitment to support the project
have spawned new research projects and collaborations that build on the TABS core. An example of
these is the Gulf of Mexico Ocean Monitoring Program, which is a National Ocean Partnership Program
component, funded through the Office of Naval Research. The project’s objective is to produce nowcasts
and forecasts of surface and subsurface velocities for the entire Gulf of Mexico and distribute them
publicly via an Internet Web page. This project and another one are funding the addition of four more
buoys to the TABS system, bringing to eleven the total number in operation by spring 1998.
Page 103INTRODUCTION
Recognizing that oil spills threaten the economic and environmental well-being of the
Texas Gulf Coast, the Texas Legislature passed the Oil Spill Prevention and Response Act of
1991, and it designated the Texas General Land Office (GLO) as the lead state agency for oil
spills in Texas coastal waters. To support the additional GLO mission, the Legislature also
created the Coastal Protection Fund through a two-cent-per-barrel fee on all crude-oil products
moving through Texas ports. With this mandate and funding, the GLO has moved aggressively
to develop its prevention program and response capabilities. (See: www.glo.state.tx.us/oilspill.)
Rapid, effective spill response can save substantial monies and greatly mitigate
environmental impact. Therefore, the GLO maintains a computer workstation that continuously
runs an oil-spill trajectory model. The model, Spillsym™, generates maps that are linked to an
ArcInfo™ Geographic Information System to assess resources at risk. However, the accuracy
and utility of any such model are almost entirely dependent on timely input of current and wind
observations. The traditional use of historical or averaged seasonal data has proved ineffective
for real-time operations, especially as a spill approaches the coast. In August 1994, the GLO
directed the Geochemical and Environmental Research Group (GERG) at Texas A&M
University (TAMU) to implement a program that would provide its computer with real-time
observations of surface currents and water temperature and a synthesis of publicly available,
real-time, marine weather data.
The Texas Automated Buoy System (TABS) became operational in April 1995 with the
deployment of its first two buoys off Galveston, Texas. At the time of this writing, TABS has
five buoys in operation, e.g., Buoy G, east of Sabine Pass, Buoys B and F off Galveston, and
Buoys D and H off Corpus Christi (Figure 1). In 1997 the GLO authorized the purchase of two
additional buoys for the South Padre Island region near Brownsville (Buoys J and K in Figure 1).
Research projects external to TABS (see below), but cooperating and cost-sharing with it, are
contributing four more buoys (Buoys I, L, M, and N in Figure 1). Thus, GERG will deploy the
six new buoys during the spring of 1998, bringing to eleven the number of active TABS sites.
TABS has proved its worth during real spills, and realistic drills. During the Buffalo
Marine Barge 292 oil spill, for example, the National Oceanic and Atmospheric Administration
HAZMAT modeling team and the GLO’s trajectory modeling team used TABS data and
computer simulations to forecast the movement of the oil to an unprecedented level of accuracy
(Martin et al., 1997). The trajectory modelers did not have to begin their work with only
educated guesses about the offshore currents. The currents were known within minutes of the
spill and were continuously tracked for the next 24 days. Midway through the spill TABS data
showed the direction of the coastal current switching from up-coast to down-coast. The benefit to
cleanup and protection operations was that the Incident Command could make the decision to
stand-down an alert to the Sabine Pass area and refocus efforts down-coast a full day earlier than
would have been possible prior to TABS.
The primary mission of TABS is to provide real-time data when the spill alarm goes off.
However, the GLO recognized from the project’s inception that three factors would form TABS
into an effective public resource as well. Thus, the GLO supports research to improve the
reliability, operational range, and versatility of the TABS buoys; it insists that all TABS data be
immediately disseminated though a user-friendly Internet Web site; and it encourages other
scientific research projects to build on the TABS resources. We focus on the success of these
aspects of the project in the following sections.
Page 104TABS Buoys Houston
SRST2
NDBC Buoys
Galveston A G
Discontinued
I
42035
Proposed NOPP B
Scheduled 12/97 C F
L
28 N
M
PTAT2 D H 42019
N
Corpus Christi
E
42020 Gulf of Mexico
26 N J K 42002
98 W 96 W 94 W
Figure 1. Map of current and future TABS buoy locations. Bathymetric contours shown for the
following depths (meters): 20, 50, 200, 500, 2000, 3500.
TABS EQUIPMENT
TABS buoys take a five-minute vector average of current velocity and water temperature
about two meters below the surface every thirty minutes. A shore-based PC computer running
LINUX automatically acquires the data via either cellular or satellite telephone four times daily
under normal conditions. Since the reporting link is fully two-way, GERG can switch to a more
frequent schedule during spills. The data are automatically transferred to a UNIX workstation
that performs QA/QC functions and adds the observations to the TABS database.
Two buoy models are now in operation. Both are schematically illustrated in Figure 2.
The original TABS I model was designed for the nearshore coastal environment and intended to
obtain just near-surface currents and water temperature. With this focus, the design could take
advantage of the large offshore area that is covered by cellular telephone service (Chaplin and
Kelly, 1995). By pulling already proven tools and technologies off the shelf and combining them
Page 105TABS II
Climatronics
Met Sensor
Antenna
Marine Lantern
TABS I
Wiring / Connector
J housing
Internal Radar
Antenna Reflector
Marine Lantern
Wiring / Connector A
Housing
Internal Radar
Reflector
4m
Solar Panels (9 total)
Solar Panels (6)
Buoy Hull Buoy Hull
Polyethylene Foam Polyethylene Foam
Interior Interior
Polyurethane Polyurethane
Fabric Skin 0.61 m 0.79 m
Fabric Skin
Cellular
Telemetry Module Lifting Bails
Aluminum Electronics
Housing with
Current Meter Satellite Telemetry
Electronics System,Data Logger,
2.4 m Current Meter Electronics
and Batteries
Protective Cage
Protective Cage
Electromagnetic
Current Sensor Electromagnetic
Current Sensor
Chain to Anchor
Chain to Anchor
NOT TO SCALE
Figure 2. Schematic diagrams of the TABS I and TABS II buoy models.
Page 106in an innovative way, the length of the R&D phase was reduced, with the first deployment taking
place just nine months from the project’s inception.
Both buoys are a modified spar design with a flotation package constructed of closed-
cell, cross-linked, polyethylene foam with a polyurethane fabric-reinforced skin. They have
built-in radar reflectors, and central stainless steel or aluminum watertight housings for the
current meter and communications electronics. A Marsh-McBirney electromagnetic 2-axis
current sensor extends from the buoy bottom. Six or nine solar panels provide power through
rechargeable batteries.
After a year-and-a-half of successful, operational, field experience with the TABS I
model, during which several modifications and upgrades were accomplished, the GLO directed
GERG to develop the “next generation” TABS buoy TABS II was developed in cooperation
between GERG and Woods Hole Group/Advanced Coastal Environmental Systems (ACES), Inc.
Magnell et al. (1998) describe the details of the new design. The four major design
enhancements are 1) a new geostationary satellite telephone system, 2) an increased size of the
flotation package, 3) an Argos satellite data transmission system that is automatically activated if
the primary communications system fails, and 4) an electronic command and control system
based on the ACES Remote System Monitor, which includes a powerful microprocessor and
multiple analog and digital I/O ports. On January 20, 1998, GERG deployed the first TABS II
buoy for test and evaluation next to Buoy B off Galveston. Initial results are excellent. The new
model buoys will be deployed at Sites I through N (Figure 1). Selected buoys will incorporate
the Climatronics TacMet meteorological package.
PUBLIC DATA DISSEMINATION
The data from the TABS buoys are available to the general public on the GERG Web
server. Users are able to access the data in both graphical and tabular formats (Lee et al., 1996).
The TABS Web page, shown in Figure 3, provides the user with access to a variety of
oceanographic and meteorological data products. Users can select a TABS buoy location from
the map or from text links for those without a graphical Web browser.
For each TABS station the user can choose to view either a graph of the past four days of
data or the data in tabular format. The graph consists of a "stick plot" of the currents, cross shelf
and along shelf components of the current and water temperature. These data are presented in
both English and metric units. The graph can be downloaded as either a GIF image or a
postscript file. TABS data are routinely updated every six hours but can be more frequently
updated as needed in the event of an oil spill. Each buoy page also contains a link that allows the
user to search the TABS database and retrieve data from a buoy for a user selectable time period.
The user can access up to two months of data at a time. The results of each database search can
be viewed in both graphical and tabular format. For example, Crout (1997) used the TABS
database features to facilitate his study comparing currents calculated from satellite altimetry
with those observed by the TABS buoys.
The TABS Web site also provides access to data from the National Data Buoy Center's
(NBDC) buoy and coastal (CMAN) meteorological data. These data are obtained from the
Global Telecommunications Stream (GTS) via the Internet. We include three offshore buoys and
two CMAN stations, e.g., 42035 located southeast of Galveston, 42019 and 42020, which are
east and southeast of Port Aransas, respectively, SRST2 near Sabine, and PTAT2 near
Page 107Figure 3. Example of TABS main Web page.
Page 108Port Aransas (Figure 1). These data are updated hourly and presented in both graphical and
tabular formats.
There are several additional features of the TABS Web site that can assist in the
utilization of the TABS data. A summary plot capability provides a stickplot for each buoy using
a common time axis. A status table lists buoy latitude, longitude, lease block and water depth.
The status table also indicates which of the buoys have successfully transmitted their data during
the past twelve hours and contains other information regarding the operational status of each
buoy. Links to National Weather Service coastal and offshore weather forecasts for the Gulf of
Mexico are provided on the main TABS Web page. The Web site also contains a number of links
to additional real-time oceanographic and meteorological data. There are links to the
Houston/Galveston PORTS Web site, the Texas Coastal Ocean Observation Network (TCOON),
Galveston Bay and Corpus Christi Bay Animated Hydrodynamic and Oil Spill Model
output, Satellite Sea Surface Temperature Images from NOAA and Johns Hopkins University,
Tampa Bay PORTS, and other relevant sites.
Analysis of the TABS Web server access logs show that utilization of the TABS Web
site has been increasing since its inception. A graph of monthly access totals is shown in Figure
4. Peak usage of the TABS Web site generally occurs in mid-October and then tails off rather
sharply. We see this as a reflection of the end of the recreational boating season and a decrease
of usage by boaters. The three largest groups of TABS users come from the .com, .edu and .net
Internet domains. The first represents commercial entities primarily from within the United
States; the second represents educational institutions in the U.S. and the last are network service
providers. However, since some of the major Internet service providers are in the .com domain,
i.e., AOL, it would appear that the majority of the use of the TABS site is coming from the
general public. There are several other noteworthy groups that access the TABS site. Some of
these are users from the Texas State government and specifically the Texas General Land Office,
users from the U.S. government, including users from NOAA, MMS, USGS and NASA. Usage
by the offshore industry includes most of the major oil companies. In addition we have seen
usage from sixty-nine foreign countries to date.
6000
Monthly Access Totals for the TABS Web Server
5000
4000
Accesses
3000
2000
1000
0
J F M A M J J A S O N D J F M A M J J A S O N D
1996 1997 1998
Figure 4. Monthly access totals for TABS Web site from January 1996 – January 1998.
Page 109TGLO TABS Buoy Current Summary
1.0 60 Buoy G North
40
0.5 20
cm s-1
knots
0.0 0
-0.5 -20
-40
-1.0 -60 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 1 0: 2 3 4
July 5
1.0 60 Buoy B North
40
0.5 20
cm s-1
knots
0.0 0
-0.5 -20
-40
-1.0 -60 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 1 0: 2 3 4
July 5
1.0 60 Buoy F North
40
0.5 20
cm s-1
knots
0.0 0
-0.5 -20
-40
-1.0 -60 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 1 0: 2 3 4
July 5
1.0 60 Buoy D North
40
0.5 20
cm s-1
knots
0.0 0
-0.5 -20
-40
-1.0 -60 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 1 0: 2 3 4
July 5
1.0 60 Buoy H North
40
0.5 20
cm s-1
knots
0.0 0
-0.5 -20
-40
-1.0 -60
0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 0: 6: 12: 18: 0:
1 2 3 4 5
July
1997
Figure 5. Stick vector plots of the current velocity measured half-hourly at five buoy locations
during the first four days of July 1997. (A stick vector points in the direction the current is
flowing, with True North at the top of the page. The length of the vector, from its base on the x-
axis to its tip, is proportional to the speed; the y-axis serves as the scale.)
Page 110RESEARCH PROJECTS THAT BUILD ON TABS
Thus far, three research projects have been funded that take advantage of the resources of
the TABS core program. The first of these is funded by the GLO itself and titled “Texas
Automated Buoy System Modeling Effort.” TABS buoys have proven highly successful at
measuring currents at specific locations. However, the coastal ocean is often highly variable in
both time and space. For example, Figure 5 shows “stick vector” plots of the current velocity
measured half-hourly at five buoy locations during the first four days of July 1997. Note the
strong, persistent, northeastward flow at Buoy D. A little farther offshore at Buoy H (Figure 1),
however, the currents are rotating clockwise with a daily period. Currents at Buoy G, east of
Sabine Pass, are frequently directed opposite to those off Galveston at Buoy B during this period.
This new two-year modeling project will assimilate currents and wind measurements and provide
estimates of currents all along the Texas Coast, thus extending the buoys’ point measurements.
A second project, titled “An Observational and Predictive Study of Inner Shelf Currents
over the Texas-Louisiana Shelf” is made possible by a combination of funding sources, including
the U.S. Minerals Management Service, Louisiana State University, TAMU, Marine Industry
Group-Gulf, and the GLO. It will add Buoy I, extending the TABS network into the coastal
waters of western Louisiana. The project’s goals are to analyze all the historical data collected by
the TABS array, compare the field data with winds and water levels in an effort to understand
better the dynamical balances present in the coastal waters of Louisiana and Texas, and develop
a dynamically consistent nowcast/forecast of the coastal currents.
The third and most ambitious project, “Gulf of Mexico Ocean Modeling System” is one
of the projects of the National Ocean Partnership Program. It is funded by the Office of Naval
Research, with Dynalysis of Princeton, Inc., serving as the lead organization. The project’s
objective is to produce nowcasts and forecasts of surface and subsurface velocities for the entire
Gulf of Mexico and distribute them publicly via an Internet Web site. The TABS contribution is
to verify model generated velocities and to provide calibration data for currents derived from
satellite altimetry along a line running across the Texas continental shelf, e.g., through Buoys B,
F, L, M, and N, approximately, in Figure 1.
CONCLUSIONS
By adopting a farsighted policy toward the TABS program the GLO has transformed a
tool critical to its oil spill response mission into a valuable public resource. The public and the
scientific community are rapidly adopting it, finding new and innovative uses for its products,
and adding to its capabilities. The new TABS II buoy is designed with expandability and
flexibility in mind. It can accommodate a variety of additional sensors for meteorology, water
optics, acoustics, and water chemistry. As the real-time observations are coupled with the
computer models being developed by various research projects, our view and understanding of
the waters offshore Texas will expand rapidly and profoundly.
ACKNOWLEDGEMENTS
The TABS project is funded by the Texas General Land Office, currently through
Contract 98-067R. Additional TABS financial support has been provided by ARAMCO Services
Page 111Co., Marine Industry Group—Gulf (MIRG), and Mobil Co. The Marine Spill Response Corp.
has provided ship support. Research projects that build on the TABS project are funded by the
Texas General Land Office under Contract 98-153R, by the U.S. Minerals Management Service
through Louisiana State University subcontract R148185, and by a National Ocean Partnership
Program project funded by the Naval Research Laboratory through Dynalysis of Princeton
subcontract 12/15/97. This paper does not necessarily reflect the views or policies of the Texas
General Land Office or of any of the other agencies and companies providing financial and
service support. Mention of trade names or commercial products does not constitute endorsement
or recommendation for use.
REFERENCES
Chaplin, G. F. and F. J. Kelly, 1995: Surface current measurement network using cellular
telephone technology. Proceedings of the IEEE Fifth Working Conference on Current
Measurement, Feb. 7-9, 1995, St. Petersburg, FL
Crout, Richard L., 1997: Coastal currents from satellite altimetry. Sea Technology, Vol. 38, No.
8, 33-37
Lee, L. L., III, F. J. Kelly and N. L. Guinasso, Jr., 1996: Armchair currents using TABS (Texas
Automated Buoy System). Eos Trans. Vol. 76, No. 3, p. OS78.
Magnell, B. A., F. J. Kelly and R. A. Arthur, 1998: A new telemetering environmental buoy for
offshore applications. Proceedings of the Oceanology International 98 Conference, 10-13 March
1998, Brighton, UK
Martin, R. A., F. J. Kelly, Linwood L. Lee III, and Norman L. Guinasso, Jr., 1997: Texas
Automated Buoy System: Real-time currents for oil spill response. Proceedings of the 1997
International Oil Spill Conference, April 7-10, 1997, Fort Lauderdale, FL.
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