Evaluation of satellite and reanalysis-based global net surface energy flux and uncertainty estimates

Author(s)
Chunlei Liu, Richard Allan, Michael Mayer, Patrick Hyder, Norman Loeb, Christopher Roberts, Maria Valdivieso, John Edwards, Pier-Luigi Vidale
Abstract

The net surface energy flux is central to the climate system yet observational limitations lead to substantial uncertainty. A combination of satellite-derived radiative fluxes at the top of atmosphere adjusted using the latest estimation of the net heat uptake of the Earth system, and the atmospheric energy tendencies and transports from the ERA-Interim reanalysis are used to estimate surface energy flux globally. To consider snowmelt and improve regional realism, land surface fluxes are adjusted through a simple energy balance approach at each grid point. This energy adjustment is redistributed over the oceans to ensure energy conservation and maintain realistic global ocean heat uptake, using a weighting function to avoid meridional discontinuities. Calculated surface energy fluxes are evaluated through comparison to ocean reanalyses. Derived turbulent energy flux variability is compared with the Objectively Analyzed air-sea Fluxes (OAFLUX) product, and inferred meridional energy transports in the global ocean and the Atlantic are also evaluated using observations. Uncertainties in surface fluxes are investigated using a variety of approaches including comparison with a range of atmospheric reanalysis products. Decadal changes in the global mean and the interhemispheric energy imbalances are quantified, and present day cross-equator heat transports are reevaluated at 0.22 ± 0.15 PW (petawatts) southward by the atmosphere and 0.32 ± 0.16 PW northward by the ocean considering the observed ocean heat sinks.

Organisation(s)
Department of Meteorology and Geophysics
External organisation(s)
Met Office, University of Reading, National Aeronautics & Space Administration (NASA)
Journal
Journal of Geophysical Research: Atmospheres
Volume
122
Pages
6250-6272
No. of pages
23
ISSN
2169-897X
DOI
https://doi.org/10.1002/2017JD026616
Publication date
2017
Peer reviewed
Yes
Austrian Fields of Science 2012
105204 Climatology
Keywords
ASJC Scopus subject areas
Forestry, Aquatic Science, Soil Science, Water Science and Technology, Earth-Surface Processes, Geochemistry and Petrology, Geophysics, Oceanography, Palaeontology, Ecology, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), Atmospheric Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/evaluation-of-satellite-and-reanalysisbased-global-net-surface-energy-flux-and-uncertainty-estimates(5a9ac5b4-18fe-4451-935d-01850d17f9a6).html