Saturated Vapor Pressure — pres_sat_vapor

Calculates the saturation vapor pressure for a given temperature.

Usage

pres_sat_vapor_p(...)

# Default S3 method
pres_sat_vapor_p(temp, ..., a = 7.5, b = 235)

# S3 method for class 'weather_station'
pres_sat_vapor_p(weather_station, ...)

Arguments

...: Named station fields, site parameters or model assumptions.
temp: Air temperature in degrees C.
a: Constant a, default is 7.5 over water.
b: Constant b, default is 235 over water.
weather_station: A weather_station object.

Value

Saturation vapor pressure in hPa.

Details

The saturation vapor pressure ($e_s$) is calculated using the formula: $$e_s = 6.1078 \cdot 10^{\left(\frac{a \cdot T}{b + T}\right)}$$ where: $T$ is the temperature in °C, $a$ and $b$ are constants that vary depending on the state of water:

Over water: $a = 7.5$, $b = 235$
Over undercooled water: $a = 7.6$, $b = 240.7$
Over ice: $a = 9.5$, $b = 265.5$

References

Bendix 2004, p. 261.

Examples

# Calculate saturation vapor pressure at a temperature of 20°C
pres_sat_vapor_p(temp = 20)
#> [1] 23.66574