Solar radiation enters the Earth's atmosphere with a portion being scattered by clouds and aerosols.

Processing, archiving and distributing Earth science data
at the NASA Langley Research Center

How is ERBE net radiation defined?

ERBE net radiation is defined at top of the atmosphere (TOA) as the following:
Net (TOA) = Solar_down (TOA) - SW_up (TOA) - LW_up (TOA)

where Solar_down (TOA) is the solar incoming flux at TOA, SW_up (TOA) is the reflected shortwave flux at TOA, and LW_up (TOA) is outgoing longwave flux at TOA. The sign convention for ERBE net radiation is that positive/negative sign represents a net radiative energy surplus/deficit of the Earth system, respectively.