hourly_temps function

Estimation of hourly temperatures from daily data

This function generates hourly temperatures from daily maximum and minimum values, using the method proposed by Linvill (1990), which also requires sunset and sunrise calculation for each day in the series. Sunset and sunrise hours for a location are internally estimated using the function solar_times from the latitude and the day of the year (DOY) using the equations by Spencer (1971) and Almorox et al. (2005).

hourly_temps(climdata, latitude)

Arguments

• climdata: a data frame containing the columns Year, Month, Day, Tmax and Tmin. Data must not contain any gap.
• latitude: the latitude of the site, in decimal degrees.

Returns

a dataframe containing the columns Date, Year, Month, Day, DOY, Hour, Sunrise (hour of sunrise), Sunset (hour of sunset), Daylength and Temp (hourly temperature).

Examples

# Generate hourly temperatures
library(magrittr)
library(dplyr)
library(lubridate)
Tudela_HT <- hourly_temps(Tudela_DW,42.13132)

References

Almorox J, Hontoria C and Benito M, 2005. Statistical validation of daylength definitions for estimation of global solar radiation in Toledo, Spain. Energy Conversion and Management 46, 1465-1471.

Linvill DE, 1990. Calculating chilling hours and chill units from daily maximum and minimum temperature observations. HortScience 25, 14-16.

Spencer JW, 1971. Fourier series representation of the position of the Sun. Search 2, 172.

Author(s)

Carlos Miranda, carlos.miranda@unavarra.es