Calculates the direct shortwave incoming radiation.
Usage
rad_sw_in(...)
# Default S3 method
rad_sw_in(datetime, lon, lat, elev, temp, slope, exposition, ...)
# S3 method for class 'weather_station'
rad_sw_in(weather_station, ...)Arguments
- ...
Named station fields, site parameters or model assumptions.
- datetime
POSIXlt or POSIXct date-time vector.
- lon
Longitude in degrees.
- lat
Latitude in degrees.
- elev
Elevation above sea level in m.
- temp
Air temperature in degrees C.
- slope
Slope in degrees.
- exposition
Exposition or aspect in degrees.
- weather_station
A weather_station object.
Details
The shortwave incoming radiation (\(SW_{in}\)) is calculated using the formula: $$SW_{in} = SW_{toa} \cdot 0.9751 \cdot T_{total} / \sin(E) \cdot \cos(\theta)$$ where: \(SW_{toa}\) is the shortwave radiation at the top of the atmosphere, \(T_{total}\) is the total atmospheric transmission, \(E\) is the solar elevation angle, \(\theta\) is the terrain angle.
Examples
# Calculate shortwave incoming radiation
example_time <- as.POSIXlt("2023-08-06 12:00:00", tz = "UTC")
rad_sw_in(datetime = example_time, lon = 10, lat = 50, elev = 100, temp = 15,
slope = 5, exposition = 180)
#> [1] 687.602