About Qnet and related budget imbalance
Net heat flux, Qnet, is computed as:
Qnet = QSW - QLW - QLH - QSH.
where QSW denotes net downward shortwave radiation, QLW net upward longwave radiation, QLH latent heat flux, and QSH sensible heat flux. The unit is W/m2.
Please pay attention to the following issues when using Qnet constructed from combining ISCCP with OAFlux-1° products.
- Currently, the combined ISCCP+OAFlux Qnet data set is capable of depicting flux variability on synoptic –seasonal-interannual timescales (see Yu et al. 2006; Yu et al. 2007). However, Qnet is not balanced; there is a net residual of O(30W/m2) when averaged over the global oceans.
- The cause of the imbalanced surface heat budget is multifaceted. There are large uncertainties in surface radiation, flux-related variables, and turbulent exchange coefficients in bulk flux parameterizations, which all contribute to the budget imbalance. See Yu 2019.