Solar flux unit

The solar flux unit (sfu) is a convenient measure of spectral flux density often used in solar radio observations, such as the F10.7 solar activity index:

1 sfu = 10⁴ Jy = 10⁻²² W⋅m⁻²⋅Hz⁻¹ = 10⁻¹⁹ erg⋅s⁻¹⋅cm⁻²⋅Hz⁻¹.

See jansky for further information about related units; one Jy = 10⁴ = 10⁻²⁶ W⋅m⁻²⋅Hz⁻¹ = 10⁻²³ erg⋅s⁻¹⋅cm⁻²⋅Hz⁻¹.

• F10.7 cm Radio Emissions | NOAA / NWS Space Weather Prediction Center