Division of Nearshore Research Texas Coastal Ocean Observation Network Dr. Gary Jeffress Dr. Patrick Michaud Jessica Tishmack May 7, 2003

Texas A&M Univ-Corpus Christi Located in Corpus Christi, Texas Focused on regional and environmental issues, especially for the Gulf of Mexico Blucher Institute focuses on measuring the earth and its processes

Division of Nearshore Research Projects Texas Coastal Ocean Observation Network NOAA/NOS Natl Water Level Obs Network Houston/Galveston PORTS National/Global Ocean Observing System TWDB Intensive Surveys Nueces Bay Salinity Project Corpus Christi Real-Time Navigation System CMP - Neural-Network Forecasting CMP - Waves

TCOON Overview Started 1988 Over 50 stations Primary Sponsors General Land Office Water Devel. Board US Corps of Eng Nat'l Ocean Service Gulf of Mexico

TCOON Overview Measurements Precise water levels Wind Temperature Barometric pressure Follows NOAA/NOS standards Real-time, online database

Typical TCOON Station Wind anemometer Radio antenna Satellite transmitter Solar panels Data collector Water level sensor Water quality sensor Current meter

Nueces Bay Salinity Project Started 1991 Informs data management officials of opportunities to avoid water releases Water quality data collected every 30 minutes

Other Real-time Systems Real-time navigation Port of Corpus Christi Port Freeport NOAA PORTS Offshore weather

Data Collection Paths

Data Management Automated acquisition, archive, processing, retrieval 10-year historical database Most processing takes place via Internet Infrastructure for other observation systems

Data Management Design Principles Preserve source data Annotate instead of modify Automate as much as possible Maintain a standard interchange format Avoid complex or proprietary components Emphasize long-term reliability over short- term costs

Uses of DNR/TCOON Data Tidal datums Littoral boundaries Oil-spill response Navigation Storm preparation/ response Water quality studies Research

Tidal Datums Used for Coastal property boundaries Nautical charts Bridge and engineering structures

Tidal Datum Schematic

New Data Collection Hardware PC-104 based computer Linux operating system Solid-state Flash memory 10 serial ports, 16 A/D channels Low power consumption Rugged for harsh environments

New Data Collection Hardware Linux operating system kernel 16MB RAM, 32MB HDD 486 or Pentium processor Concurrent processes GNU shell/tools cron bash gcc

Research Real-time automated data processing Tidal datum processing Web-based visualization and manipulation of coastal data Neural network based forecasts from real- time observations Specialized sensor and data acquisition system development Support for other research efforts

Water Level Graph

Water Level Forecasting …what will happen next? Isidore begins to (re-)enter the Gulf…

Tide Predictions Tide The periodic rise and fall of a body of water resulting from gravitational interactions between Sun, Moon, and Earth. Tide and Current Glossary, National Ocean Service, 2000 According to NOS, changes in water level from non-gravitational forces are not “tides”.

Harmonic Analysis Standard method for tide predictions Represented by constituent cosine waves with known frequencies based on gravitational (periodic) forces Elevation of water is modeled as h(t) = H 0 +  H c f y,c cos(a c t + e y,c – k c ) h(t) = elevation of water at time t H 0 = datum offset a c = frequency (speed) of constituent t f y,c e y,c = node factors/equilibrium args H c = amplitude of constituent c k c = phase offset for constituent c

Harmonic Tide Predictions Obtain amplitudes and phases of harmonic constituents from trusted sources (e.g., NOS) or Perform a least-squares analysis on observations to determine amplitudes and phases of harmonic constituents To predict tides using harmonic analysis:

Harmonic Prediction Apply the amplitudes/phases to get:

Prediction vs. Observation It’s nice when it works…

Prediction vs. Observation …but it often doesn’t work in Texas

Water Level != Tide In Texas, meteorological factors have a significant effect on water elevations.

Uses of Harmonic Predictions However, harmonic predictions can still be useful! Consider… …what will happen next? Isidore begins to (re-)enter the Gulf…

Uses of Harmonic Predictions If we add harmonic prediction… …what will happen next?

Uses of Harmonic Predictions

landfall

Isidore & JFK Causeway Effect of Isidore at JFK causeway

Harmonic Water Level Predictions Present Capabilities Automated system for computing harmonic constituent values from observations database Harmonic predictions available via query page for many TCOON stations

Water Level Prediction (Near) Future Capabilities Persistent model forecast Apply difference between latest observation and harmonic prediction to future predictions Forecasts page on DNR web site Obtain forecasts from different models Harmonic predictions Persistent model Neural-network model Linear-regression/statistical model Hybrid models Information about water-level forecasting methods Statistics on previous forecasts

Neural Network Forecasting Use neural network to model non-tidal component of water level Reliable short-term predictions CCNAS ANN 24-hour Forecasts for 1997 (ANN trained over 2001 Data Set)

Forecasts in Storm Events CCNAS ANN 12-hour Forecasts During 1998 Tropical Storm Frances (ANN trained over 2001 Data Set)

Conclusions Long-term, data-rich observation network Web-based infrastructure for automated collection and processing of marine data Research in datum computation and coastal forecasting