TideData

TideData[spec]

returns the tidal properties for a location or a set of tidal parameters.

TideData[spec,prop]

returns the specified property for the location or tidal parameters indicated.

TideData[spec,prop,datespec]

returns the value of a specified property for a date or set of dates.

Details and Options

  • spec can be a location, tide station, a TimeSeries of tidal heights or an association with keys corresponding to the tidal modes, mean tide level and elevation.
  • For spec that encompass regions, the center of that region is used to determine the tide station.
  • TimeSeries input is analyzed to determine the best-fit values for tidal modes, which are then used for further calculations.
  • Tidal modes should be specified as an ordered pair of amplitude and phase. If not specified, they are assumed not to contribute.
  • Amplitudes and heights can be specified as Quantity objects. If numbers, they are presumed to be in feet.
  • Phases should be Quantity objects or numbers specifying angular degrees.
  • The tidal constituents and their symbols are:
  • "M2"M2principal lunar semidiurnal constituent
    "S2"S2principal solar semidiurnal constituent
    "N2"N2larger lunar elliptic semidiurnal constituent
    "K1"K1lunar diurnal constituent
    "M4"M4shallow water overtides of principal lunar constituent
    "O1"O1lunar diurnal constituent
    "M6"M6shallow water overtides of principal lunar constituent
    "MK3"MK3shallow water terdiurnal constituent
    "S4"S4shallow water overtides of principal solar constituent
    "MN4"MN4shallow water quarter diurnal constituent
    "NU2"ν2larger lunar evectional constituent
    "S6"S6shallow water overtides of principal solar constituent
    "MU2"MU2variational constituent
    "2N2"2"N2lunar elliptical semidiurnal second-order constituent
    "OO1"OO1lunar diurnal constituent
    "LAM2"λ2smaller lunar evectional constituent
    "S1"S1solar diurnal constituent
    "M1"M1smaller lunar elliptic diurnal constituent
    "J1"J1smaller lunar elliptic diurnal constituent
    "MM"Mmlunar monthly constituent
    "SSA"Ssasolar semiannual constituent
    "SA"Sasolar annual constituent
    "MSF"Msflunisolar synodic fortnightly constituent
    "MF"Mflunisolar fortnightly constituent
    "RHO"ρlarger lunar evectional diurnal constituent
    "Q1"Q1larger lunar elliptic diurnal constituent
    "T2"T2larger solar elliptic constituent
    "R2"R2smaller solar elliptic constituent
    "2Q1"2Q1larger elliptic diurnal constituent
    "P1"P1solar diurnal constituent
    "2SM2"2SM2shallow water semidiurnal constituent
    "M3"M3lunar terdiurnal constituent
    "L2"L2smaller lunar elliptic semidiurnal constituent
    "2MK3"2"MK3shallow water terdiurnal constituent
    "K2"K2lunisolar semidiurnal constituent
    "M8"M8shallow water eighth diurnal constituent
    "MS4"MS4shallow water quarter diurnal constituent
  • A location can be specified by latitude/longitude pairs, assuming degrees as units, a GeoPosition specification or Entity objects, assuming they represent objects with geographic coordinates.
  • Location-specific properties include:
  • "Coordinates"coordinates of tide station
    "DateEstablished"date tide station established
    "DateInstalled"date tide station installed
    "DateRemoved"date now-defunct tide station removed
    "GreatDiurnalRange"difference between "MeanHigherHighWater" and "MeanLowerLowWater"
    "HighestWaterLevelOnStationDatum"highest recorded water level
    "LowestWaterLevelOnStationDatum"lowest recorded water level
    "MeanDiurnalHighWaterInequality"average difference in height between high tides
    "MeanDiurnalLowWaterInequality"average difference in height between low tides
    "MeanDiurnalTideLevel"average of "MeanHigherHighWater" and "MeanLowerLowWater"
    "MeanHigherHighWater"average highest high tide of the day
    "MeanHighWater"average of high tides
    "MeanLowerLowWater"average lowest low tide of the day
    "MeanLowWater"average of low tides
    "MeanSeaLevel"average water level
    "Position"coordinates of the location
    "Station"tide station Entity used
    "StationDistance"distance to tide station used
    "StationName"name of tide station used
  • Calculated properties include:
  • "HighHighTide"highest high tide for the day's predicted time and height
    "HighNeapTide"next high neap tide's predicted time and height
    "HighSpringTide"next high spring tide's predicted time and height
    "HighTide"next high tide's predicted time and height
    "LowHighTide"next low spring tide's predicted time and height
    "LowLowTide"lowest low tide for the day's predicted time and height
    "LowNeapTide"next low neap tide's predicted time and height
    "LowTide"next low tide's predicted time and height
    "WaterLevel"current water level relative to the mean
  • General properties include:
  • "Elevation"elevation
    "HarmonicAmplitudes"amplitudes of harmonic constituents for input
    "HarmonicPhases"phases of harmonic constituents for input
    "MeanTideLevel"average level of tide
  • Universal harmonic constituent properties include:
  • "HarmonicNames"names of harmonic constituents
    "HarmonicSpeeds"angular speeds of harmonic constituents
  • All heights are measured relative to the tide station datum or fixed-base elevation, often the zero of the first tide staff installed.
  • datespec should be specified as a specific time using a date list, a DateObject or as a string in DateString format.
  • datespec can also be specified as {start,end,increment} for compatibility with DateRange specifications. increment can be any valid DateRange increment. A datespec of {start, end} uses an increment of "Minute".
  • Times are returned in either the local time zone or the time zone of the location specified.
  • The option UnitSystem is available for controlling the units of the results. The following settings can be used:
  • "Imperial"return results in imperial units
    "Metric"return results in metric units

Examples

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Basic Examples  (3)

Learn the time and predicted height for the next high tide:

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Discover the first high spring tide of a month:

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Plot the change in water levels over time:

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Scope  (6)

Options  (1)

Applications  (5)

Neat Examples  (2)

See Also

StandardOceanData  MoonPosition  MoonPhase  SunPosition  WeatherData

Introduced in 2017
(11.2)