tt_hourly_pp: Hourly Air Temperature Interpolation

In weaana: Analysis the Weather Data

Hourly Air Temperature Interpolation

Description

Computes hourly estimates of air temperature (Ta) from daily Tmin, Tmax, and day length using the method of Goudriaan (1994). The function assumes a sinusoidal temperature variation during daylight hours and an exponential decay after sunset.

Usage

tt_hourly_pp(tmin, tmax, tmax_b, tmin_a, lat, doy)

Arguments

tmin	Numeric. Minimum temperature of the day (°C).
tmax	Numeric. Maximum temperature of the day (°C).
tmax_b	Numeric. Maximum temperature from the previous day (°C).
tmin_a	Numeric. Minimum temperature of the following day (°C).
lat	Numeric. Latitude of the location (degrees, -90 to 90).
doy	Integer. Day of the year (1 to 366).

Details

- **Daytime interpolation**: During sunlight hours, Ta is estimated using a sinusoidal curve fitted between Tmin and Tmax. - **Nighttime interpolation**: After sunset, Ta follows an exponential decline from the sunset temperature to the next morning's Tmin. - **Sunrise and Sunset Calculation**: - Sunrise hour: 'hsrise = 12 - d/2' - Sunset hour: 'hsset = 12 + d/2' - Tmax occurs at hour = 13.5.

If the Controlled Environment module is used for weather data, the function takes hourly values from that instead of computing them.

Value

A numeric vector of length 24 containing the estimated hourly air temperatures (°C).

References

Goudriaan, J. (1994). Advanced Methods for Calculating Radiation Models. Netherlands Journal of Agricultural Science, 42(4), 315-323.

Examples

tmin <- 10
tmax <- 20
tmax_b <- 21
tmin_a <- 11
lat <- -27
doy <- 10
hourly_temps <- tt_hourly_pp(tmin, tmax, tmax_b, tmin_a, lat, doy)

weaana documentation built on Nov. 5, 2025, 6:08 p.m.