Extreme Overirradiance events and their spectral distribution in Lima, Peru

We report on 'extreme overirradiance' events measured in Lima, Peru. The highest measured irradiance value was 1543 W/m2 on March 23rd, 2020. The measurements were carried out by four different, independent instruments, all simultaneously recording their maximum values. The spectral distribution of the extreme overirradiance event was also recorded and compared to the spectral distributions of a clear and a cloudy sky. The extreme overirradiance phenomenon demonstrated an irradiance enhancement in the entire measured spectrum, but predominantly in the visible and the near infrared region of the spectrum (450 nm to 1100 nm). This spectral enhancement leads to a redshift of the spectrum during the extreme overirradiance event, as is observed by its lower average photon energy in comparison to the clear and cloudy sky spectra.