1. NOAA’s National Ocean Service Coastal Tide Stations Support Tsunami Detection and Warning
Good afternoon/morning. Introduce yourself. I am here today to discuss the coastal tide gauge network operated by NOAA’s Center for Operational Oceanographic Products and Services, part of the National Ocean Service, and specifically its support for operational tsunami warning capability, and NOAA’s Tsunami Program.
Kelly Stroker, NOAA National Geophysical Data Center (NGDC)
Allison Allen and Stephen Gill, NOAA National Ocean Service, Center for Operational Oceanographic Products and Services (CO-OPS)

2. NOAA’s National Weather Service Tsunami Warning Centers
West Coast and Alaska Tsunami Warning Center
NOAA’s National Weather Service currently operates two Tsunami Warning Centers: The West Coast and Alaska Tsunami Warning Center in Alaska, and the Pacific Tsunami Warning Center in Hawaii. These Centers are responsible for issuing tsunami warnings to all US coasts, and rely on several types of data sets from a variety of sources. We will focus today on water level data, which comes to the Centers from three primary US sources, not including data received from a wide range of international tide gauges. Each Center operates their own network of coastal tide stations, with real-time water level data transmitted via satellite. They also utilize data from the University of Hawaii Sea Level Center gauges, both in the US and abroad. Finally, they receive near real-time coastal tide data from NOAA, National Ocean Service, Center for Operational Oceanographic Products and Services (CO-OPS). This is the network we will focus on in this talk, but it is important to note that that is only one piece of an integrated observation system.
Pacific Tsunami Warning Center

3. National Water Level Program
National Water Level Observation Network (NWLON) 200 Permanent Stations
A primary responsibility of CO-OPS is the operation and maintenance of the National Water Level Program, the backbone of which is the National Water Level Observation Network, or NWLON, consisting of 200 water level stations as of July 2007, including the Great Lakes, Puerto Rico, and the USVI, as well as Hawaii and several Pacific Islands. NWLON stations are long-term water level stations that measure real-time data (available online or by phone) and provide valuable information regarding short and long-term sea level variations, and tidal datums. “Long-term” means that the station has operated, or will be operated, for a minimum of 19 years, which is the period over which tidal datums are computed. Many of these stations have been in for decades, with the longest continuous water level record being just over 150 years in San Francisco, CA. This network of long-term station is augmented by short-term and historic stations installed for a variety of applications, including marsh restoration and hydrographic survey.

4. APPLICATIONS SUPPORTED BY THE NATIONAL OCEAN SERVICE’S
NWLON
Function Application
Navigation/Safety Real-Time Navigation,
Hydrographic Surveys,
Airborne Hydrography, HAZMAT Response ...etc.
Environmental Assessment/ Wetland Delineation, Coastal
Monitoring Zone Management; Enforcement,
Insurance, Storm Surge,
Tsunami Warning…etc.
Basic & Applied Research Modeling, Wetland Studies, Global Warming Studies,
Sea Level Change, Estuarine/
Hydrodynamic Studies…etc.
NWLON tide data are used for a wide variety of applications, including but not limited to navigation, storm surge mitigation, tsunami warning, and restoration science.

5.
This is the CO-OPS website. All of our data, and many of our products, are available for free here. (This slide is hidden, included for more information if necessary)

6. National Water Level Program NWLON Measurement Systems
This is one common NWLON water level station configuration. This schematic shows a long-term, or “control”, station, as evidenced by the tide house. Tide houses are built to last at least years, though the components will be replaced more frequently, and annual inspections and maintenance are done on the station each year. To the left is a diagram of the components of a water level station. The tide house is often on a pier, but may have additional support structure to ensure sustainability. Long-term tide houses contain a primary and backup DCP, data collection platform, and a Geostationary Operational Environmental Satellites (GOES) antenna to transmit water level data. The 6-inch diameter well in the picture contains an acoustic sensor and sounding tube. It takes 181 instantaneous water level measurements, once a second for three minutes, and that value is averaged for a six minute value. The parallel plates and 2-inch orifice at the bottom of the well dissipate both wind wave energy and turbulent flow past the orifice so there are no significant biases in the water level readings inside and outside the well.. The acoustic gauges are backed up pressure sensors and a DC. Pressure sensors are used to fill in gaps in acoustic sensor data and do not have the physical measurement upper limit that the acoustic sensors have and they also operate better in the presence of surface ice. Most of the NWLON stations are powered primarily through solar power, with battery backups inside the tide house. Data is transmitted through a GOES antenna, and received near real-time at CO-OPS as well as at the tsunami warning centers. All tide stations, whether short or long-term, are referenced form the sensor reference zero to a benchmark system via differential leveling and/or GPS, so that tidal datums can be recovered, even after the water level station is gone. NWLON stations can have a suite of meteorological sensors added to them, including air temp, water temp, barometric pressure, wind speed and direction, and conductivity. The stations are designed and built by NOAA, with manufacturing contracted out. NWLON stations are being upgraded with a new data collection platform, called an Xpert system (we will discuss in a bit what effect that has on water level observation and data transmission). A new freestanding single steel piling structure design to be used in areas of severe storm surge (Gulf of Mexico) is being implemented at stations in that are this year.

7. Continuous Operational Real-Time Monitoring System (CORMS)
CO-OPS monitors water level data as they arrive using a Continuous Operational Real-Time Monitoring System (CORMS). CORMS provides real time quality assurance and control through a combination of human analysis and flags set for various tidal parameters, such as rate of change, that alert watchstanders of events, changes, or potential problems. All COOPS data and products are monitored and reviewed on a 24x7 basis by experienced watchstanders on 12-hour rotations. When a problem is detected, appropriate action is taken immediately to either remedy the situation within CORMS or notify the appropriate headquarters, or IT personnel to take corrective measures. Dissemination of data is temporarily stopped if necessary until the problem is solved, to ensure dissemination of accurate data only.
While CORMS provides a preliminary near real-time quality control measure, all 6-minute water level data are quality controlled by a trained expert during post processing and routine product dissemination. Data processing involves checking the data for errors, such as false spikes, checking it for consistency, filling any data gaps, tabulating high and low tide heights, deriving hourly tide data, tabulating extremes, and calculating monthly means and tidal datums. There are several measures taken to detect shifts, biases, or changes. Routine checks include checks for abnormal rates of change, abnormal flat spots, and abnormal out-of-range data. In addition to data quality flags, based on the checks listed above, gain and offsets for the backup pressure data are routinely calculated and checked for abnormalities between primary and backup sensor data. Comparisons are made with predicted tides and with data from nearby stations. If any significant errors are noted in this process, corrective action can be taken, either to correct the data or to repair malfunctioning sensors or DCPs at the station. A verifier then checks the data and subsequent products to ensure accuracy, and verified data are stored in a database and made available online, typically within one month of the end of each calendar month.

8. NOS Benchmark Leveling
Bench Mark Photos
NOS uses a double run method for differential leveling, which includes a forward run and back run, with at least one spur to ensure accuracy. Levels are run upon station installation and removal, as well as annually to check the tide station and surrounding area for stability. Each NWLON station has a network of at least 10 tidal benchmarks associated with it, at least 5 of which are leveled each year. Geodetic relationships are obtained at tidal benchmarks wherever possible.
NOS Benchmark Leveling

9. P/ATWC Specific NWLON Stations Post-1960
The relationship between CO-OPS’ NWLON and the tsunami warning systems is not a new one. This image shows the stations in Alaska that have been tied directly to the Alaska Tsunami Warning Center for many years.
NWLON stations directly connected to ATWC
NWLON and long term secondary stations

10. Beginning in 2005, there was an emphasis on strengthening tsunami warning networks around the world.
However, the December 2004 Indian Ocean event brought the awareness of the danger of tsunamis and need for enhanced warning systems to the spotlight. Beginning in 2005, CO-OPS was tasked to coordinate with the NOAA Tsunami Warning Centers in upgrading existing stations with new Data Collection Platform (DCP) and communications technology and with expanding the tsunami warning capabilities of the NWLON. Work began in 2005 to upgrade 33 existing water levels and install 16 new stations from the Pacific Ocean to the Caribbean Sea by October At this time all 33 upgrades have been completed, and the final installation, at Port Alexander, AK, is scheduled for August 2007.
(Xpert is a new type of data collection platform, an upgrade from the older Sutron system)
In the US and US territories, 16 locations were identified for new NWLON sites, and 33 existing NWLONs were identified for upgrade to the new Xpert system.

11. Emergency mode transmits every six minutes with six minute averages
The most notable enhancement to the upgraded tsunami stations, with the new Data Collection Platforms, was the fact that 1-minute averaged water level data are now recorded and disseminated, rather than just the 6-minute data standard to all of our NWLON stations.
Before stations were upgraded, 6-minute data were transmitted hourly to CO-OPS, and to the Tsunami Warning Centers, with a mechanism for higher rate transmission if triggered into “emergency mode” by a rate of change flag. In that state, stations would transmit 6 minute data every 6 minutes.

12. Upgrade
No emergency mode: transmits every six minutes with one and six minute averages
After upgrade, the stations now routinely disseminate (via GOES) every 6 minutes 1 6-minute averaged water level value and 6 1-minute water level values. The Tsunami Warning Centers were recently given access to CO-OPS Domestic Satellites, to use as a redundant source of data to the NWS Gateway, to ensure continuous data dissemination whenever possible.

13. In addition to the 1-minute data, the new tsunami stations also record 15-second water level data on the backup DCP. These stations store the 15-second data on a flash drive for post event analyses and modeling. The 15-second data can be manually downloaded from the station itself or remotely using the DCP modem. The Tsunami Warning Centers have direct access via GOES, remote phone dial-in, and the CO-OPS web pages to the 6-minute and 1-minute data (1-minute data in emergency mode only for the older systems).
Xpert DCPs are equipped with modems and are accessible by phone for diagnostics, firmware upgrades, reconfiguration, troubleshooting, and data retrieval wherever phone or cellular service is available. CO-OPS can utilize this existing capability to support the Tsunami Warning Centers. Continuous real-time 15-second data cannot be accessed through Xpert DCPs by phone at this time, but efforts are underway to reach this goal.

14. Tide Data Path through CO-OPS
GOES
Satellite
NESDIS
Wallops Island, VA
DOMSAT Seattle
DOMSAT Chesapeake
NWS DOMSAT
NWSTG Server
(6) Averaged 1-min WL values plus
(1) Averaged 6-min WL value
Every 6 minutes for our stations in AK,
West Coast and Pacific Islands
Sutron Xpert DCPs:
(both record 6-min averaged data)
-primary - also records 1-min values
-backup - 15 sec average (not transmitted, but available via phone or direct serial connection)
NWLON
Database Server
National PORTS® Database Server
Water Level Station
The Tsunami Warning Centers can access CO-OPS water level data in several ways, in order to maintain continuous data dissemination whenever possible. They have direct access via GOES (through both the NWS gateway and Domestic Satellites), remote phone dial-in, and the CO-OPS web pages to the 6-minute and 1-minute data (1-minute data in emergency mode only for the older systems).
Abbreviations and Acronyms:
CO-OPS - Center for Operational Oceanographic Products and Services
CORMS-Continuous Operational Real-Time Monitoring System Environment
DCP - Data Collection Platform
GOES - Geostationary Operational Environmental Satellite (NOAA)
NESDIS - National Environmental Satellite, Data and Information Services
NWSTG - National Weather Service Telecommunication Gateway
NWLON - National Water Level Observing Network
PORTS - Physical Oceanographic Real Time System
CO-OPS Web Page
CO-OPS Tsunami Web Page
(in its final review stages)
CORMS
Quality Control Operator
Tsunami Warning Centers
FTP Server

15. NOAA’s 49 NATIONAL WATER LEVEL OBSERVATION NETWORK
TSUNAMI TIDE STATIONS
Existing Stations with Tsunami capability (33)
ALASKA
New Stations with Tsunami capability (16)
Neah Bay, WA
La Push, WA
Cordova, AK
Yakutat, AK
Westport, WA
Elfin Cove, AK
Toke Point, WA
Seward, AK
Sitka, AK
Garibaldi, OR
Kodiak, AK
Port Alexander, AK
South Beach, OR
Alitak, Kodiak, AK
Charleston, OR
WEST COAST
Sand Point, AK
King Cove, AK
Atka, AK
Unalaska, AK
Nikolski, AK
Port Orford, OR
Adak, AK
Crescent City,CA
Nawiliwili, HI
North Spit,CA
Mokuoloe, HI
Most of the 16 new stations and 33 stations identified for upgrade were on the West Coast, Pacific, and Alaska, but several installations and upgrades were also done in the Caribbean.
HAWAII
Arena Cove, CA
Honolulu, HI
Kahului, HI
Kawaihae, HI
Hilo, HI
Point Reyes,CA
Monterey, CA
Midway
PUERTO RICO &
Port San Luis, CA
Wake Island
VIRGIN ISLANDS
PACIFIC ISLANDS
Santa Barbara, CA
Guam
Kwajalein
Santa Monica, CA
Los Angeles, CA
St. John
Aguadilla Pier
Culebra
Mona Island
La Jolla, CA
Vieques, Esperanza
Pago Pago
St.Croix

16. NOAA Caribbean Tide Stations Supporting Tsunami
Current Tsunami Tide Stations
Expanded Tsunami Tide Stations
Charlotte Amalie,
St. Thomas
San Juan
Culebra Island
Aguadilla
Puerto Rico
Red diamonds indicate newly established tsunami stations in the last two years. Blue dots indicate existing NWLON stations that were upgraded to an Xpert data collection platform and configured to be “tsunami-ready”. In addition, CO-OPS is working with the Puerto Rico Seismic Network to install a network of 6 additional tide stations throughout Puerto Rico, using the same equipment and standards as the NWLON stations.
Lameshur Bay,
St. John
Vieques Island
Mona Island
Christiansted,
St. Croix
Magueyes Island
Lime Tree Bay,
St. Croix

17. This is a photo of the tsunami station at Christiansted Harbor, on St
This is a photo of the tsunami station at Christiansted Harbor, on St. Croix. It shows a typical configuration on a pier. You can point out the acoustic well, GOES antenna, and solar panels. There is a sticker on the front explaining the use of the station.

18. However, CO-OPS has surpassed the original goal of 49 stations supporting tsunami warning, by performing systematic upgrades of all NWLON stations (other than those in the Great Lakes), including the East and Gulf Coasts. As of the end of June 2007, there were officially 107 NWLON stations configured to support tsunami warning.
100% of operational NWLON stations in AK, HI, PI, PR, VI, CA, OR, WA and Pacific Islands are currently upgraded with Sutron Xpert system, as well as 34 in the East and Gulf Coasts.
This graphic shows all of the tsunami stations configured today, except for the Pacific Islands.

19. CO-OPS Tsunami Web Page
As mentioned earlier, the CO-OPS tsunanami web page was developed in support of the Tsunami Warning Centers, to provide access to water level data and station information. Data can be plotted from this site, including a detided residual curve. Stations appear here as soon as their upgrade is complete.
(At this point in time, this still isn’t technically a public page, so I have not included the url, but for your information it’s tidesandcurrent.noaa.gov/tusnami)

20. This is a screen capture from the website following the November 2006 Kurill Islands event, showing the arrival time and height of the first wave. The purple line illustrates the residual detided plot, essentially the observed water level with predicted water level removed. So what you’re seeing there is solely the effect of the tsunami.
Midway Islands

21. CO-OPS Performs Harmonic Analysis on DART data to “detide” the signal and enhance tsunami observation capabilities
(I just wanted to briefly point out the detide process for DARTS as well. You may have better slides for this, and certainly are familiar with the process- so feel free to point out whatever you feel is most important.) This is a paragraph Natalia wrote, but adjust it to compliment what you might be talking about within your own talk as needed.
CO-OPS performs harmonic analysis on DART data and provides the constants to the Tsunami Warning Centers (TWCs) and the National Data Buoy Center (NDBC), in order to develop research quality deep-ocean water level data and products. We download high and low frequency DART data from the NDBC website, conduct preliminary 3-month harmonic analysis, and a final 1-year harmonic analysis in order to compute harmonic constituents using CO-OPS standard harmonic analysis program and predictions based on hourly data. We generate observed and predicted data sets for de-tiding and plotting “in-house” as quality control of the analysis; to check for discontinuities, datum shifts, and invalid data. We also evaluate harmonic constants according to reduction of variance analysis for both 3-months and 1-year data availability intervals. And finally, we provide the resulting harmonic constants to TWCs and NDBC for de-tiding and creating predictions, which they have their own software package to do.
The resulting harmonic constants are essential to the new tsunami forecast system (TFS). As the tsunami wave propagates across the ocean and successively reaches the DART systems, these systems report sea level information measurements back to the Tsunami Warning Centers, where the information is processed (and also  will be de-tided) to produce a new and more refined estimate of the tsunami source. An increasingly accurate forecast of the tsunami will be used to issue warnings and watches.   The data will also provide NOS with information on offshore tidal characteristics.   For planning purposes and software development, PMEL also generated harmonic constants for all the stations in the full, expanded DART Network. This was done using the state-of-the-art global tide model TXPO 6.2 developed at Oregon State University. The model harmonic constants from this model have compared well with ones observed at DART stations. So our harmonic constants are used for model evaluations and research.

22. This is one example of a detided plot at one DART station east of Miami. Residuals are computed by subtracting predicted from observed tide. Predictions are generated from harmonic constants.

23. Summary
The NOS has been a pro-active force in National hazard warning.
Technology upgrades are enhancing the ability of the multi-mission NWLON to meet emerging challenges.
With new and upgraded NWLON, the NOS looks forward to the continuance of protecting America’s citizens and coasts.
So… in summary…
The NOS has been a pro-active force in National hazard warning.
Technology upgrades are enhancing the ability of the multi-mission NWLON to meet emerging challenges.
With new and upgraded NWLON, the NOS looks forward to the continuance of protecting America’s citizens and coasts.

24. Please provide my email address Allison. Allen@noaa
Please provide my address or phone number x166 to anyone with questions or wanting greater detail. I will also be available by phone or that week if you want to get back to anyone quickly with answers to any questions that come up. Thank you again for helping us out with this!!!
Thank You Please contact Allison Allen with questions: x166