Abstract
AbstractTwo methods are developed to estimate net surface energy fluxes based upon satellite‐derived reconstructions of radiative fluxes at the top of atmosphere and the atmospheric energy tendencies and transports from the ERA‐Interim reanalysis. Method 1 applies the mass‐adjusted energy divergence from ERA‐Interim, while method 2 estimates energy divergence based upon the net energy difference at the top of atmosphere and the surface from ERA‐Interim. To optimize the surface flux and its variability over ocean, the divergences over land are constrained to match the monthly area mean surface net energy flux variability derived from a simple relationship between the surface net energy flux and the surface temperature change. The energy divergences over the oceans are then adjusted to remove an unphysical residual global mean atmospheric energy divergence. The estimated net surface energy fluxes are compared with other data sets from reanalysis and atmospheric model simulations. The spatial correlation coefficients of multiannual means between the estimations made here and other data sets are all around 0.9. There are good agreements in area mean anomaly variability over the global ocean, but discrepancies in the trend over the eastern Pacific are apparent.
Highlights
The absolute mean value of net radiation imbalance at the top of atmosphere (TOA) is a key climate variable, providing an estimate of total energy gain of the Earth system and a link between radiative forcing, ocean heat uptake and surface temperature response
Both are obtained from ERA Interim; this method is considered more accurate than using Evap − P directly from the reanalysis, since water vapor is assimilated, but precipitation is a simulated variable that is highly dependent upon model parameterisations
Similar procedures are applied to MERRA data [Mayer et al, 2013] to obtain mass adjusted total energy divergence EDmass−MERRA which is substituted into equation (6) to obtain the net downward surface flux from the mass adjusted energy divergence (Fmass)−MERRA
Summary
The absolute mean value of net radiation imbalance at the top of atmosphere (TOA) is a key climate variable, providing an estimate of total energy gain of the Earth system and a link between radiative forcing, ocean heat uptake and surface temperature response. The net energy fluxes at the earth’s surface, including short and long-wave radiation and the sensible and latent heat fluxes, are very important for the study of surface temperature change, and the atmospheric and oceanic circulations. Accurate estimation of the surface energy fluxes is essential for understanding both the short term temperature hiatus [Easterling and Werner, 2009; Knight et al, 2009; Trenberth and Fasullo, 2013a; Huber and Knutti, 2014; Watanabe et al, 2014] and long term climate change [Otto et al, 2013]. We apply an atmospheric energy divergence approach [Chiodo and Haimberger, 2010; Mayer and Haimberger, 2012] using two different methods to estimate the net downward surface energy fluxes by combining reconstructed net radiation fluxes at TOA [Allan et al, 2014] with the energy tendencies and lateral divergence simulated by the ERA-Interim reanalysis [Dee et al, 2011; Berrisford et al, 2011]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
