TCARI Goes Operational: Improvements for Field Use and the Development of an

Error ModelBarry Gallagher

LCDR Rick BrennanMonica Cisternelli

Stephen Gill

hoursMLLW

MLLW

Discrete Tide ZoningDiscrete Tide Zoning

Shortfalls of Discrete Tide Shortfalls of Discrete Tide ZoningZoning

• The inability to account for The inability to account for inequalities in the high water and inequalities in the high water and low water intervals.low water intervals.

• Final water levels applied to a Final water levels applied to a polygon are based on a single polygon are based on a single gauge; therefore unable to account gauge; therefore unable to account for changes in tide type (i.e. diurnal, for changes in tide type (i.e. diurnal, semi-diurnal, or mixed). semi-diurnal, or mixed).

• Introduce a “step” in the digital Introduce a “step” in the digital elevation model.elevation model.

• The geographic polygons are The geographic polygons are computed manually - severely computed manually - severely limiting the size and number that limiting the size and number that may be reasonably created.may be reasonably created.

• TCARI overcomes discrete zoning TCARI overcomes discrete zoning weaknesses.weaknesses.

• Originally developed by Dr. Kurt Hess Originally developed by Dr. Kurt Hess in 1995 at NOAA’s Coast Survey in 1995 at NOAA’s Coast Survey Development Laboratory . Development Laboratory .

• Separates water levels into tidal and Separates water levels into tidal and non-tidal components and interpolates non-tidal components and interpolates each separately.each separately.

• Interpolates Tidal Constituents, Interpolates Tidal Constituents, Residual water level, and desired Residual water level, and desired vertical datum across project area.vertical datum across project area.

TTidal idal CConstituent onstituent AAnd nd RResidual esidual IInterpolationnterpolation

(TCARI)(TCARI)

TCTCARIARI• Tidal component Tidal component

may be broken may be broken down into its down into its “harmonic “harmonic constants”.constants”.

• 37 Used by 37 Used by NOAA.NOAA.

• Describes orbital Describes orbital frequencies and frequencies and precession.precession.

TCATCARRII

• Non-tidal is Non-tidal is induced by induced by weather and weather and riverine riverine discharge.discharge.

Residual

TCARI EnhancementsTCARI Enhancements• Ported from Fortran to PythonPorted from Fortran to Python• Operates within NOAA’s in-house Operates within NOAA’s in-house

software Pydrosoftware Pydro• Utilizes Pletzer and Mollis Ellipt2D solver Utilizes Pletzer and Mollis Ellipt2D solver

to interpolate. to interpolate. • Has two tool kits to support both project Has two tool kits to support both project

preparation and field data applicationpreparation and field data application• Includes a complete water level Includes a complete water level

uncertainty modeluncertainty model• Writes Caris Line-Tide files directly into Writes Caris Line-Tide files directly into

HDCS data using HIPS I/O LibraryHDCS data using HIPS I/O Library

Project PreparationProject Preparation• Import high resolution shoreline NGSImport high resolution shoreline NGS• Establish open-ocean boundaries Establish open-ocean boundaries • Conduct an oceanographic and data Conduct an oceanographic and data

review of project area. review of project area. • Import tidal constituents, datum Import tidal constituents, datum

offset values, and uncertainty offset values, and uncertainty values. values.

• Create weighting function grids for Create weighting function grids for the residuals, tidal constituents, the residuals, tidal constituents, datums, and uncertainties datums, and uncertainties

• QC and transmit to field. QC and transmit to field.

Load Shoreline and Load Shoreline and Tide StationsTide Stations

Compute Water Area Compute Water Area MeshMesh

Compute Weighting Compute Weighting FunctionsFunctions

Harmonic ConstantsHarmonic Constants

Shipboard ProcessShipboard Process• Load TCARI *.tc filesLoad TCARI *.tc files• Load observed water level Load observed water level

datadata• Create HDCS Line Tide Files Create HDCS Line Tide Files

(TideLineSegments and (TideLineSegments and TideTmIDX)TideTmIDX)

Uncertainty ModelUncertainty Model• Propagates the following:Propagates the following:

• Observed water level uncertaintiesObserved water level uncertainties• Datum uncertaintiesDatum uncertainties• Resultant vertical uncertainty of TCResultant vertical uncertainty of TC

• Applies an interpolation Applies an interpolation uncertainty based on “all-water” uncertainty based on “all-water” distance from tide station to POIdistance from tide station to POI

Water Level Uncertainty

@ P.O.I.

Interpolation Uncertainty

• Thermal• Current Draw Down• Wave• Density• Marine Growth

• Spatial Quantization• Temporal Quantization• Format

Tidal Datum Uncertainty

WL Obs Uncertainty

Measurement Calibration Dynamic Effect Leveling Max/Min

Interp.Record Length

Gauge/staff Comparison

Astronomic Uncertainty

Record Length

Water Level Uncertainty Water Level Uncertainty FieldField

Future WorkFuture Work• Improved automation Improved automation • Integration to HIPS TPE Integration to HIPS TPE

computationcomputation• Support other tide-related Support other tide-related

NOAA work NOAA work (photogrammetry)(photogrammetry)

ConclusionsConclusions• TCARI provides a robust process TCARI provides a robust process

for both project preparation and for both project preparation and water level adjustmentwater level adjustment

• Overcomes discrete tide zone Overcomes discrete tide zone shortcomingsshortcomings

• Uncertainty model provides Uncertainty model provides increased resolution for increased resolution for application to sounding TPEapplication to sounding TPE