Mosaic access to realtime data from the TOGA-TAO array of moored buoys

Abstract

Realtime data from the TOGA-TAO Array of moored buoys is being made available through a Mosaic interface designed by the TAO Project office at NOAA's Pacific Marine Environment Laboratory, in Seattle, Washington. At present, displays include latitude-time plots, longitude-time plots and latitude-longitude plots of surface variables, and are being expanded to include additional views of the four-dimensional data set from this array of buoys, including animations of the buoy data and comparisions of the buoy data with operational analyses model data from the National Meteorological Center. For more information, see URL http://www.pmel.noaa.gov/toga-tao/home.html, or contact Nancy Soreide, nns@pmel.noaa.gov.

1. Introduction

2. TAO

2.1 TAO Project Overview

The Tropical Ocean-Global Atmosphere (TOGA) Tropical Atmosphere Ocean (TAO) array of Autonomous Temperature Line Acquisition System (ATLAS) moorings and Profile Telemetry of Upper Ocean Currents (PROTEUS) moorings has grown from a single mooring deployed on the Equator in 1980 and will be completed with seventy moorings in 1994. The TAO array is presently supported by five nations (United States, Japan, Korea, France, and Taiwan). The TAO Project Office located at PMEL, in Seattle Washington, is headed by Dr. Michael J. McPhaden. Information about the TAO Project is available via Mosaic (http://www.pmel.noaa.gov/toga-tao/home.html).

A TOGA-TAO Implementation Panel, instituted under sponsorship of the International TOGA Scientific Steering Group is ensuring a coordinated multinational approach to implementation of TAO as a as part of national and international climate program plans when TOGA ends in December 1994. After 1994, the array will be maintained in support of the Climate Variability and Prediction Program (CLIVAR), Global Ocean Observing System (GOOS), and Global Climate Observing System (GCOS). Among major users of the data from the array are the National Meteorological Center (NMC), European Centre for Medium- Range Weather Forecasting (ECMWF), and FNOC, which are now assimilating TAO data into numerical weather prediction models, and impact studies are under way to assess resultant improvements in operational analyses and predictions.

In 1993, approximately 15 refereed scientific journal articles were published using TAO data, in addition to approximately 25 technical reports, articles in meeting proceedings, published abstracts, and news articles. About 60% of these involve PMEL authors. Research at PMEL has focused in part on a description of the 1991-1993 El Niņo-Southern Oscillation (ENSO) that evolved differently from any previous ENSO in the past 40 years (i.e., the period over which sufficient data exist to make meaningful comparisons). An analysis of ocean-atmosphere coupling on intraseasonal time scales has shown that surface winds associated with atmospheric convection propagating from the Indian Ocean to the Pacific Ocean excites equatorial Kelvin waves, which can be traced into the eastern Pacific Ocean. These linked Indo-Pacific phenomena may play an important role in the dynamics of ENSO. Other studies include examination of the role of shallow haloclines in the heat budget of the western Pacific; the statistics of rainfall variability and its relationship to rainfall west of the dateline; a basin-scale description of the diurnal cycle in the tropical Pacific; the relationship between diurnal heating, surface heat fluxes, internal mixing, and internal waves in the cold-tongue region; descriptive and diagnostic studies of the annual cycle of currents and temperature in the tropical Pacific; the importance of trade wind fetch in determining the strength of the Equatorial Undercurrent; validation of sea level measurements from the TOPEX/POSEIDON altimeter; the role of instability waves in determining the distribution of CO_2 gas concentrations in the equatorial cold tongue; the importance of clouds versus evaporative heat flux in limiting maximum SSTs in the western equatorial Pacific warm pool; and scale analyses of upper ocean thermal variability using moored time series data, with a view toward improving thermal field sampling strategies for short-term climate studies.

2.2 The TAO Buoys

The TAO array (Hayes, et. al., 1991, McPhaden, 1993) consists of seventy ATLAS wind and thermistor chain and current meter moorings, spanning the Pacific Basin from 95W to 137E in the Equatorial wave guide from 8N to 8S (Fig 1). The TAO moorings are surface buoys moored to the ocean bottom in approximately 5000 meters of water. Basic instrumentation for the ATLAS moorings, which form the bulk of the array, includes measurements of surface wind, air temperature, relative humidity, and sea surface temperature, and subsurface temperatures at ten locations in the upper 500 meters of the water column (photograph in Fig 1, schematic diagram in Fig 2). TOGA-TAO also includes a small number of Profile Telemetry of Upper Ocean Currents (PROTEUS) and conventional current-meter moorings along the equator, to measure upper ocean currents. PROTEUS and ATLAS moorings are similar in design and instrumentation. PROTEUS in addition measures and telemeters current profiles in the upper 250 m from a downward-looking acoustic Doppler current meter mounted in the surface buoy (McPhaden et al., 1991b) (photograph in Fig 1, schematic diagram in Fig 3). Some of the TAO buoys are more heavily instrumented, such as those deployed in the western Pacific during the TOGA-COARE intesive study of the warm pool, and those which are verification sites for the TOPEX/Poseidon satellite.

2.3 The TAO Data

Buoys are constructed and sensors are calibrated at PMEL. Deployed buoys transmit data to the NOAA ARGOS satellite system, which telemeters the data to a Service ARGOS ground station. The Service ARGOS ground station applies calibrations obtained from PMEL and transmits the data to the oceanographic and meteorological community via the Global Telecommunications System. The raw data is transmitted to PMEL via Internet, where it enters the PMEL TAO Data management system (Fig 4). Automated procedures are utilized to apply calibrations, monitor buoy electronics and sensor performance, and perform data quality control checks. PMEL provides the data to outside users by a variety of methods. Data is submitted to the National Data Centers, monthly submissions are made to the National Meteorological Center's Climate Analysis Center Bulletin and Climate Diagnostics Bulletin, and FTP directories contain TAO data sets which are updated daily by automated procedures. The TAO Display Software, which delivers realtime and historical TAO buoy data to users in a point-and-click, Unix or X-windows workstation environment, has been distributed to oceanographic and meteorological institutions world wide (Soreide, et., al, 1992, 1993, 1994, 1995), and is described in Mosaic (http://www.pmel.noaa.gov/toga-tao/taows.html). More recently, the TAO Project office has developed Mosaic access to information about TAO and to displays of the realtime and historical TAO buoy data.

3. Mosaic Access

3.1 TAO

Mosaic pages (http://www.pmel.noaa.gov/toga-tao/home.html) provide extensive information about the TAO Project, the TAO buoys, the TAO Implementation Panel, TAO scientific publications, and TAO data availability by a variety of methods. Realtime data from the TOGA-TAO Array of moored buoys is being now made available through a Mosaic interface (http://www.pmel.noaa.gov/toga-tao/realtime.html). Although this is a very new development effort, displays presently include latitude-time plots , longitude-time plots (Fig 5) and latitude-longitude plots (Fig 6a) of surface variables. The user selects display parameters, such as the time, geographic location, and variable to be plotted, from pull-down menus. All plots include data received at PMEL during the previous night.

Figure 5. Time-Longitude Plots of (a) Anomalies of Zonal wind and SST and (b) Dynamic Height.

Animations of the buoy data and comparisions of the buoy data with operational analyses model data from the National Meteorological Center are also selectable from a pull-down menu. Example animation frames are shown in Fig 6. In order to broaden data access to include users who do not have viewers installed, all plots are displayed as in-line images. Animations are provided in mpeg format, and are more demanding of the Mosaic client, since they require that an mpeg viewer be installed, and that adequate memory is available for the animation file.

Figure 6. Animation Frames of (a) TAO wind and SST and (b) Heat Content from TAO buoys and NMC model.

Already use of Mosaic has widened public access to information about the TAO project and to data from the TAO buoys. We anticipate expanding this development effort to include additional views of the four-dimensional data set from this array of buoys.

3.2 PMEL

The TAO Project utilization of Mosaic has taken place in the framework of a laboratory and campus environment which is very supportive of information technology management. In June of 1989, Jim Holbrook, Deputy Director of PMEL initiated an effort to explore how the laboratory could benefit from videotex technology. In January 1990, under the technical supervision of Laura McCarty, PMEL introduced its text-based information system prototype, PMEL Info. The laboratory management perceived PMEL Info to be of continuing value, and has continued to support PMEL Info, which delivers information such as ship schedules, seminar announcements, staff meeting minutes, and budget reports in a text-based menu interface. The increased availability of Internet connections and high-powered personal workstations, coupled with growing interest in developing Mosaic pages for PMEL has culminated in the formation of a group at PMEL charged with preparing a prototype PMEL Home Page that would serve to inform the public about ongoing PMEL work. By building on the experience gained from the PMEL Info development, the PMEL Home Page at http://www.pmel.noaa.gov/ was developed, with multiple layers of diverse information, within a few months. Concomitantly, work is presently underway to replace PMEL Info's menu interface with a Mosaic implementation.

3.3 Northwest NOAA Network

A campus network demonstration project, funded by NOAA's Earth Science Data Information Management program, has been establishing a testbed for NOAA networking at the NOAA Western Regional Center in Seattle, Washington. As part of this project, it has been proposed that a campus-wide information system be built that utilizes Mosaic for its presentation layer. Cooperative work has begun, involving coordination between diverse groups, such as the National Weather Service, National Marine Fisheries Service, the Pacific Marine Center, National Environmental System Data Information Service (NOAA library functions), and Western Administrative Service Center, among others. Several Mosaic pages of significant interest are already accessible in prototype form within the Northwest NOAA Network.

4. PMEL Mosaic Utilities

4.1 Background

Mosaic forms have been used to create facilities enabling casual selective access to very large, potentially dynamic collections of previously prepared image files. At PMEL, most of the Mosaic page development is being done by individual scientific research projects, where the HTML page authoring process has been seen as something relatively straightforward. However, Mosaic forms require the existence of a suitable executable to process the input generated by the form. Therefore, PMEL has started the development of a library of modules to process the input generated by the HTML FORM tags, by name. These HTML FORMS related utilities free developers from the requirement to parse the information obtained from the FORM, allowing creation of functional forms by a wider group of developers. These reusable modules were utilized in the development of the HTML FORMs based access to realtime TAO buoy data, and are described below.

4.2 Generic Look-up Modules for use in authoring Mosaic Forms

File naming conventions are used to uniquely identify the content of each file in the collection. These utility modules prepare a valid path name (or multiple path names) from the forms input values. The path name is formulated by concatenation. Hidden fields may be used by the forms author to supply additional information, although every variable has a default value as well. All modules are coded in C. Two modules have been completed, and more are under development. The completed modules are:

1. InlineImage, which prepares an HTML file referencing the image file using the IMG tag. Header and footer information are included if indicated by the presence of the respective variables, and
2. StartViewer, which returns the file itself to the client, rather than preparing an HTML file. The file extension is interpreted in the normal way by the client, which is responsible for starting up the appropriate viewer.

1. MultiInlineImage, which is a variation on InlineImage, and which returns multiple images, probably as a list of hypertext links.
   
2. StartAny, which will enable a form to serve as an input variable collection mechanism for any application that the forms author wishes to make available via Mosaic.

5. Conclusions

For more information about the TAO project and TAO data access, please contact Nancy Soreide, TAO Project Office, NOAA/PMEL, Seattle, WA (206-526-6728)
Internet: nns@pmel.noaa.gov OR taogroup@noaapmel.gov OR OMNET: TAO.PMEL
TAO Project Mosaic URL: http://www.pmel.noaa.gov/toga-tao/home.html.

References

Hayes, S.P., L.J. Mangum, J. Picaut, A. Sumi and K. Takeuchi (1991): TOGA-TAO: A moored array for real-time measurements in the tropical Pacific Ocean. Bull. Am. Met. Soc., 72 (3), 339-347.

McPhaden, M.J., 1993: TOGA-TAO and the 1991-93 El Nino-Southern
Oscillation Event. Oceanography, 6, 36-44.

Soreide, N.N., D.C. Mc Clurg, D.W. Denbo, W.H.Zhu, D.J. Doll, L.J.Mangum, L.D. Stratton, and S.P. Hayes, 1992: "Atlas Data Management and Interactive Data Display for the TOGA-TAO Array of Moored Buoys." Proceedings of the MTS'92 Conference, Vol II, October 19 21, 1992, Washington, D.C., p. 457 463.

Soreide, N.N., D.W. Denbo, D.C. McClurg, W.H. Zhu, and S.P. Hayes, 1993: "TAO Workstation Display Software for the TOGA-TAO Equatorial Array of Moored ATLAS and Current Meter Buoys." Proceedings of the Ninth International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography and Hydrology. January 17 22, 1993, Anaheim, CA, p. 315 320.

Soreide, N.N., D.C. McClurg, W.H. Zhu, M.J. McPhaden, L.J. Mangum and D.W. Denbo (1994): Distribution and display of TOGA-TAO buoy data. Proceedongs, Oceans '94 OSATES, 13-16 September 1994, Parc de Penfeld, Brest, France (in press).

Soreide, N.N., D.C. McClurg, W.H. Zhu, and D.W. Denbo, M.J. McPhaden, 1995 "TAO Display Software for TOGA-TAO Buoy Data." Proceedings of the Eleventh International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography and Hydrology. January 15-20, 1995, Dallas, TX, (in press).

Laura C. McCarty, Vita

Academic Training:
BA Computer Science U.C. Berkeley, California 1976

Present Position:
Computer Specialist, NOAA/Pacific Marine Environmental Laboratory, Seattle, WA.
Chair of PMEL Mosaic Working Group.
Chair of Northwest NOAA Network Mosaic Working Group.
Computer-mediated communication. (lmccarty@pmel.noaa.gov)

Dai C. McClurg, Vita

Academic Training:
B.S. Geophysics, U.C. Berkeley, California, 1983
M.S. Geophysics, Seismololgy, U. of Washington, Seattle, 1987.
Thesis Title: "Coda-Q Analysis at Mt. St. Helens"
Ph.D. Candidate, U. of Washington, Seattle, 1987-1989.
Deep Earth Structure from Diffracted Seismic Waves. Robust Methods.

Present Position:
Computer Specialist/Geophysicist, NOAA/PMEL/Ocean Climate Research Division, Seattle, 1989-present.
TAO Data Management and Analysis. TAO Display Software Development.
EPIC Software Development and Support. (dai@pmel.noaa.gov)

Nancy N. Soreide, Vita

Academic Training:
BS Towson State College, Towson, MD Mathematics 1964
MA University of Washington, Seattle, WA Mathematics 1974


Present Position:
System Analyst, NOAA/Pacific Marine Environmental Laboratory, Seattle, WA.
Project leader for PMEL/EPIC Data Management and TAO software development.
Oceanographic data management, display and analysis. (nns@pmel.noaa.gov)

Corresponding Author