For example, the calculations of Haywood et al. (1999) showed that the clear - sky outgoing flux at the TOA over oceans yields excellent agreement with Earth Radiation Budget Experiment (ERBE) observations when aerosol species are considered. (nap.edu)
Clouds could be a negative feedback because they reflect so much of the incoming flux, but they also may reflect some of the outgoing flux back to the surface. (scienceofdoom.com)
This is also then the approximate location of the spectrally averaged TAU = 1 level from which most of outgoing flux can be said to originate from. (realclimate.org)