This function calculates the temperature (°C) from relative humidity (%) and dew point temperature (°C).
Usage
calcTemp(RH, DewP, method = c("Magnus", "Buck"))
Details
This function supports two methods for temperature calculation:
"Magnus"
(default): Uses the August-Roche-Magnus approximation, valid for 0°C < Temp < 60°C and 1% < RH < 100%."Buck"
: Uses the Arden Buck equation with Bögel modification, valid for -30°C < Temp < 60°C and 1% < RH < 100%.
The methods calculate temperature based on vapor pressure and saturation vapour
pressure relationships.
The Magnus method is chosen as the default because it is more stable
when used with the calcDP
and calcRH_DP
functions.
References
Alduchov, O. A., and R. E. Eskridge, 1996: Improved Magnus' form approximation of saturation vapor pressure. J. Appl. Meteor., 35, 601–609
Buck, A. L., 1981: New Equations for Computing Vapor Pressure and Enhancement Factor. J. Appl. Meteor. Climatol., 20, 1527–1532, https://doi.org/10.1175/1520-0450(1981)020<1527:NEFCVP>2.0.CO;2.
Buck (1996), Buck (1996), Buck Research CR-1A User's Manual, Appendix 1.
https://bmcnoldy.earth.miami.edu/Humidity.html
Examples
# Calculate temperature for RH 50\% and Dew Point 15°C using Magnus method
calcTemp(50, 15)
#> [1] 26.24387
# Using Buck method
calcTemp(50, 15, method = "Buck")
#> [1] 26.29922
calcTemp(50, calcDP(20, 50))
#> [1] 20
# mydata file
filepath <- data_file_path("mydata.xlsx")
mydata <- readxl::read_excel(filepath, sheet = "mydata", n_max = 5)
mydata |>
dplyr::mutate(
DewPoint = calcDP(Temp, RH),
Temp_default = calcTemp(RH, DewPoint),
Temp_Buck = calcTemp(RH, DewPoint))
#> # A tibble: 5 × 8
#> Site Sensor Date Temp RH DewPoint Temp_default Temp_Buck
#> <chr> <chr> <dttm> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 London Room 1 2024-01-01 00:00:00 21.8 36.8 6.38 21.8 21.8
#> 2 London Room 1 2024-01-01 00:15:00 21.8 36.7 6.34 21.8 21.8
#> 3 London Room 1 2024-01-01 00:29:59 21.8 36.6 6.30 21.8 21.8
#> 4 London Room 1 2024-01-01 00:44:59 21.7 36.6 6.22 21.7 21.7
#> 5 London Room 1 2024-01-01 00:59:59 21.7 36.5 6.18 21.7 21.7