rh_from_wetbulb {heatindex}R Documentation

Relative humidity from wet-bulb temperature

Description

rh_from_wetbulb calculates the relative humidity from the thermodynamic (or psychrometric) wet-bulb (or ice-bulb) temperature using the Rankine-Kirchhoff approximations.

Usage

rh_from_wetbulb(
  p,
  T,
  Tw,
  psychrometric = FALSE,
  icebulb = FALSE,
  verbose = TRUE,
  lewis = 0.85
)

Arguments

p

The total air pressuire in Pa. This can be a single number, a vector, a matrix, or an array.

T

The absolute air temperature in Kelvin. This can be a single number, a vector, a matrix, or an array.

Tw

The thermodynamic (or psychrometric) wet-bulb (or ice-bulb) temperature in Kelving. This can be a single number, a vector, a matrix, or an array.

psychrometric

A logical indicating whether to interpret Tw as the psychrometric (if TRUE) or thermodynamic (if FALSE) version. Default is FALSE.

icebulb

A logical indicating whether to interpret Tw as the ice-bulb (if TRUE) or wet-bulb (if FALSE) version. Default is FALSE.

verbose

A logical indicating whether or not to print warning messages. Default is TRUE.

lewis

The Lewis number for moist air. Default is 0.85.

Value

Relative humidity in the same shape as p, T, and Tw. The relative humidity is reported with respect to liquid water if T is greater than or equal to 273.16 K and with respect to ice if T is less than 273.16 K.

Author(s)

David M. Romps romps@berkeley.edu

References

Romps, D. M. (2025). Wet-bulb temperature from pressure, relative humidity, and air temperature. In review.

Examples

rh_from_wetbulb(1e5,300,290)
rh_from_wetbulb(1e5,301:310,290)
rh_from_wetbulb(1e5,301:310,291:300)
rh_from_wetbulb(1:10*1e4,301:310,291:300)

[Package heatindex version 0.0.2 Index]