... Three day radio-astronomical forecast of the proton activity of the Sun: The figure shows multiwave radio emission scans - graphs of the distribution of intensity I and circular polarization V across the solar disk, obtained at RATAN-600. ... According to this criterion, for a proton flare to arise, the flux of radio emission must be sufficiently high at short wavelengths (blue color scans) and should increase with time compared to the general intensity. ... More about the solar activity . ...