Interpolate Hourly Temperature Values using APSIM HourlySinPpAdjusted.

Interpolates hourly temperatures from daily minimum and maximum temperatures using the APSIM HourlySinPpAdjusted method. Daytime temperatures are sinusoidal and nighttime temperatures follow an exponential cooling curve. Day length, sunrise and sunset are calculated from latitude and date.

Usage

interpolate_hourly_sin_pp_adjusted(
  mint,
  maxt,
  date,
  latitude = NULL,
  hourly = FALSE
)

Arguments

mint

A numeric vector of daily minimum temperatures.

maxt

A numeric vector of daily maximum temperatures.

date

A Date vector with the same length as mint, used to determine the day of year for day length calculations.

latitude

Latitude of the site (deg) as a single numeric value.

hourly

A logical value indicating whether to return hourly temperatures. If FALSE, daily mean temperatures are returned.

Value

A numeric vector of daily mean temperatures, with one value per input day if hourly = FALSE. If hourly = TRUE, a data frame is returned with columns date, mint, maxt, hour, and temp.

Examples

mint <- c(10, 11, 12)
maxt <- c(30, 31, 32)
date <- as.Date(c("2020-01-01", "2020-01-02", "2020-01-03"))
interpolate_hourly_sin_pp_adjusted(mint, maxt, date = date, latitude = -27.5)
#> [1] 20.18884 21.17367 22.00730

hourly <- interpolate_hourly_sin_pp_adjusted(
    mint, 
    maxt, 
    date = date, 
    latitude = -27.5, 
    hourly = TRUE
)
library(ggplot2)
hourly |>
    ggplot(aes(x = timestamp, y = temp)) +
    geom_line() +
    geom_point(aes(x = timestamp, y = mint), color = "blue") +
    geom_point(aes(x = timestamp, y = maxt), color = "red") +
    theme_bw() +
    labs(
        x = "Date Time", 
        y = "Temperature (°C)", 
        title = "Hourly Temperature Interpolation"
    )