What is Net radiation; radiative surplus and deficit?

Example 27.7 (The reanalysis’s global budget)

Averaged over the globe, the reanalysis receives $341.9\,\mathrm{W}\,\mathrm{m}^{-2}$, reflects $117.0\,\mathrm{W}\,\mathrm{m}^{-2}$ (an albedo of $0.342$), absorbs $224.8\,\mathrm{W}\,\mathrm{m}^{-2}$ and emits $237.7\,\mathrm{W}\,\mathrm{m}^{-2}$: a net radiation of $-12.9\,\mathrm{W}\,\mathrm{m}^{-2}$. The OLR is within $1.3\,\mathrm{W}\,\mathrm{m}^{-2}$ of the assessed $239\,\mathrm{W}\,\mathrm{m}^{-2}$, but the reflection is $17\,\mathrm{W}\,\mathrm{m}^{-2}$ larger than the assessed $100\,\mathrm{W}\,\mathrm{m}^{-2}$. A real imbalance of this size would cool the Earth by $6.6\,\mathrm{PW}$; it is an error of the model, not a property of the Earth, and the transport below is computed after removing the global mean.