Solar ecliptic length — sol_ecliptic

Calculates the solar ecliptic length, which is the angle of the Earth's orbit around the sun relative to the vernal equinox.

Usage

sol_ecliptic_length(...)

# Default S3 method
sol_ecliptic_length(datetime, ...)

# S3 method for class 'weather_station'
sol_ecliptic_length(weather_station, ...)

Arguments

...: Named station fields, site parameters or model assumptions.
datetime: POSIXlt or POSIXct date-time vector.
weather_station: A weather_station object.

Value

Degree.

Details

The solar ecliptic length ($L$) is calculated as: $$L = 279.3 + 0.9856 \cdot J + 1.92 \cdot \sin(M)$$ where: $J$ is the Julian day, $M$ is the solar medium anomaly in radians.

References

Bendix 2004, p. 243.

Examples

# Calculate solar ecliptic length
sol_ecliptic_length(as.POSIXlt("2022-06-21"))
#> [1] 449.2837