virtual.temp {bigleaf} | R Documentation |

## Virtual Temperature

### Description

Virtual temperature, defined as the temperature at which dry air would have the same density as moist air at its actual temperature.

### Usage

```
virtual.temp(
Tair,
pressure,
VPD,
Esat.formula = c("Sonntag_1990", "Alduchov_1996", "Allen_1998"),
constants = bigleaf.constants()
)
```

### Arguments

`Tair` |
Air temperature (deg C) |

`pressure` |
Atmospheric pressure (kPa) |

`VPD` |
Vapor pressure deficit (kPa) |

`Esat.formula` |
Optional: formula to be used for the calculation of esat and the slope of esat.
One of |

`constants` |
Kelvin - conversion degree Celsius to Kelvin |

### Details

the virtual temperature is given by:

`Tv = Tair / (1 - (1 - eps) e/pressure)`

where Tair is in Kelvin (converted internally). Likewise, VPD is converted
to actual vapor pressure (e in kPa) with `VPD.to.e`

internally.

### Value

`Tv -` |
virtual temperature (deg C) |

### References

Monteith J.L., Unsworth M.H., 2008: Principles of Environmental Physics. 3rd edition. Academic Press, London.

### Examples

```
virtual.temp(25,100,1.5)
```

*bigleaf*version 0.8.2 Index]