For more explanations about solar radiation and latent and sensible flux, please have a look at the specific page concerning the radiation.
The radiation maps are available in hourly steps. It is possible to combine the radiation map with wind animation and the graticule by activating the different options in the lower right corner with one click.
The solar radiation map shows the incoming shortwave radiation in W/m².
It represents the incoming solar radiation, and that is why it is mainly equal to zero during the night (no sun). This map gives also an indication on the cloud coverage.