sirad (version 2.0-2)

su: Supit-Van Kappel solar radiation model

Description

'su()' calculates daily solar radiation based on daily cloud coverage and temperature range using Supit-Van Kappel model.

Usage

su(days, lat, A, B, C, tmax, tmin, CC)

Arguments

days

Vector of class 'Date' of length n.

lat

Latitude in decimal degrees.

A

Supit-Van Kappel model coefficient 'A'.

B

Supit-Van Kappel model coefficient 'B'.

C

Supit-Van Kappel model coefficient 'C'.

tmax

Vector of length n containing daily maximum temperature [C].

tmin

Vector of length n containing daily minumum temperature [C].

CC

Vector of length n containing daily cloud coverage [octas].

Value

• Vector of length n of daily solar radiation [MJm-2].

Details

Supit and Van Kappel proposed a method for estimating solar radiation from daily cloud coverage and temperature range.

References

Supit, I. 1994. Global radiation. Publication EUR 15745 EN of the Office for Official Publications of the EU, Luxembourg. Supit, I., Kappel, R.R. van, 1998. A simple method to estimate global radiation. Solar Energy, 63:147-160.

See Also

'sucal' to calibrate the model.

Examples

require(zoo)
data(Metdata)
tmax <- Metdata$meteo$TEMP_MAX
tmin <- Metdata$meteo$TEMP_MIN
cc <- Metdata$meteo$CLOUD_DAYTIME_TOTAL
days <- Metdata$meteo$DAY
lat <- Metdata$LATITUDE
plot(zoo(su(days=days, lat=lat, A=0.07, B=0.54, C=-0.2, tmax=tmax, tmin=tmin, CC=cc),order.by=days))