Division of Nearshore ResearchTexas Coastal OceanObservation Network

Dr. Gary Jeffress Mr. James RizzoOctober 2003

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 ofMexico

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

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

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 Forecasting

…what will happen next?

Isidore begins to (re-)enter the Gulf…

Tide Predictions

TideThe 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”.

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

Harmonic Water Level PredictionsPresent 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

75 80 85 90 95 100 105 110 115 120 125

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Wat

er L

evel

s (m

)

Julian Day,1997

CCNAS ANN 24-hour Forecasts for 1997 (ANN trained over 2001 Data Set)

Forecasts in Storm Events

230 235 240 245 250 255 260 265 270 2750

0.2

0.4

0.6

0.8

1

1.2

Wat

er L

evel

s (m

)

Julian Day,1998

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

NN Model, 24 Hr prediction

Harmonic Analysis

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