bccal {sirad} | R Documentation |
Calibrate Bristow-Campbell model
Description
Function estimates Bristow-Campbell model coefficient 'B' based on reference data
Usage
bccal(lat, days, rad_mea,extraT=NULL,BCc=2,Tmax, Tmin, tal)
Arguments
lat |
Latitude in decimal degrees. |
days |
Vector of class 'Date' of length n. |
rad_mea |
Vector of length n containing reference (e.g. measured) solar radiation [MJm-2]. |
extraT |
Optional. Vector of length n of extraterrestrial solar radiation [MJm-2]. If 'NULL' then it is calculated by the function. Providing extraterrestrial solar radiation speeds up the computation |
BCc |
Bristow-Campbell model coefficient 'C' usually equaled to 2. |
Tmax |
Vector of length n containing daily maximum temperature [C]. |
Tmin |
Vector of length n containing daily minumum temperature [C]. |
tal |
Clear sky transmissivity. |
Details
Function estimates Bristow-Campbell model coefficient 'B' based on reference (e.g. measured) solar radiation data. It performs a non-linear least squeres regression.
Value
BCb |
Bristow-Campbell 'B' coefficient |
Author(s)
Jedrzej S. Bojanowski
References
Bristow, K.L., and G.S. Campbell. 1984. On the relationship between incoming solar radiation and daily maximum and minimum temperature. Agriculture and Forest Meteorology, 31:159-166.
See Also
'bc', and 'bcauto' to perform auto-calibration
Examples
data(Metdata)
tmax <- Metdata$meteo$TEMP_MAX
tmin <- Metdata$meteo$TEMP_MIN
days <- Metdata$meteo$DAY
lat <- Metdata$LATITUDE
rad_mea <- Metdata$meteo$RAD_MEA
bccal(lat,days,rad_mea,extraT=NULL,BCc=2,tmax,tmin, tal=0.76)