R: Seawater thermal expansion coefficient

swAlpha {oce} | R Documentation

## Seawater thermal expansion coefficient

### Description

Compute alpha, the thermal expansion coefficient for seawater.

### Usage

    swAlpha(salinity, temperature = NULL, pressure = 0, longitude = NULL,
      latitude = NULL, eos = getOption("oceEOS", default = "gsw"))

### Arguments

`salinity` | either practical salinity (in which case `temperature` and `pressure` must be provided) or an `oce` object (in which case `salinity`, etc. are inferred from the object).
`temperature` | in-situ temperature [degC], defined on the ITS-90 scale; see “Temperature units” in the documentation for `swRho`.
`pressure` | pressure [dbar]
`longitude` | longitude of observation (only used if `eos="gsw"`; see ‘Details’).
`latitude` | latitude of observation (only used if `eos="gsw"`; see ‘Details’).
`eos` | equation of state, either `"unesco"` or `"gsw"`.

### Value

Value in 1/degC.

### Author(s)

Dan Kelley

### References

The `eos="unesco"` formulae are based on the UNESCO equation of state, but are formulated empirically by Trevor J. McDougall, 1987, Neutral Surfaces, Journal of Physical Oceanography, volume 17, pages 1950-1964. The `eos="gsw"` formulae come from GSW; see references in the `swRho` documentation.

### See Also

Other functions that calculate seawater properties: `T68fromT90`, `T90fromT48`, `T90fromT68`, `swAbsoluteSalinity`, `swAlphaOverBeta`, `swBeta`, `swCSTp`, `swConservativeTemperature`, `swDepth`, `swDynamicHeight`, `swLapseRate`, `swN2`, `swPressure`, `swRho`, `swRrho`, `swSCTp`, `swSTrho`, `swSigma0`, `swSigma1`, `swSigma2`, `swSigma3`, `swSigma4`, `swSigmaTheta`, `swSigmaT`, `swSigma`, `swSoundAbsorption`, `swSoundSpeed`, `swSpecificHeat`, `swSpice`, `swTFreeze`, `swTSrho`, `swThermalConductivity`, `swTheta`, `swViscosity`, `swZ`

[Package oce version 1.1-1 Index]