Refracted zenith angle of the sun beneath the surface

Snell's-law refraction of the solar beam entering water: \(\theta_w = \arcsin(\sin\theta_{air} / n)\). As the in-air zenith approaches 90 degrees the refracted angle approaches the edge of Snell's window (about 48.6 degrees for n = 1.333); see snells_window.

Usage

refracted_solar_angle(sun_zenith, n = 1.333)

Arguments

sun_zenith

In-air solar zenith angle in degrees, [0, 90].

n

Refractive index of water. Default 1.333.

Value

Refracted (in-water) solar zenith angle in degrees. Vectorised.

See also

snells_window, underwater_polarization

Examples

refracted_solar_angle(0)    # 0
#> [1] 0
refracted_solar_angle(90)   # ~48.6 (edge of Snell's window)
#> [1] 48.60663