The Observed State of the Energy Budget in the Early Twenty-First Century

• Published in: Journal of climate Vol. 28; no. 21; pp. 8319 - 8346
• Main Authors: L’Ecuyer, Tristan S., Beaudoing, H. K., Rodell, M., Olson, W., Lin, B., Kato, S., Clayson, C. A., Wood, E., Sheffield, J., Adler, R., Huffman, G., Bosilovich, M., Gu, G., Robertson, F., Houser, P. R., Chambers, D., Famiglietti, J. S., Fetzer, E., Liu, W. T., Gao, X., Schlosser, C. A., Clark, E., Lettenmaier, D. P., Hilburn, K.
• Format: Journal Article
• Language: English
• Published: Boston American Meteorological Society 01.11.2015
• Subjects: Algorithms; Atmospherics; Brackish; Climate models; Clouds; Datasets; Downwelling; Earth surface; Energy budget; Energy budgets; Enthalpy; Estimates; Fluctuations; Global climate models; Heat content; Heat flux; Heat transfer; Hydrologic cycle; Hydrological cycle; Land; Marine; Meteorological satellites; Meteorology; Net radiation; Ocean basins; Ocean circulation; Oceans; Precipitation; Radiation balance; Satellite observation; Seasonal variability; Seasonal variation; Seasonal variations; Sensible heat; Short wave radiation; Turbulent heat transfer; Water cycle
• ISSN: 0894-8755; 1520-0442
• DOI: 10.1175/jcli-d-14-00556.1

New objectively balanced observation-based reconstructions of global and continental energy budgets and their seasonal variability are presented that span the golden decade of Earth-observing satellites at the start of the twenty-first century. In the absence of balance constraints, various combinations of modern flux datasets reveal that current estimates of net radiation into Earth’s surface exceed corresponding turbulent heat fluxes by 13–24 W m−2. The largest imbalances occur over oceanic regions where the component algorithms operate independent of closure constraints. Recent uncertainty assessments suggest that these imbalances fall within anticipated error bounds for each dataset, but the systematic nature of required adjustments across different regions confirm the existence of biases in the component fluxes. To reintroduce energy and water cycle closure information lost in the development of independent flux datasets, a variational method is introduced that explicitly accounts for the relative accuracies in all component fluxes. Applying the technique to a 10-yr record of satellite observations yields new energy budget estimates that simultaneously satisfy all energy and water cycle balance constraints. Globally, 180 W m−2of atmospheric longwave cooling is balanced by 74 W m−2of shortwave absorption and 106 W m−2of latent and sensible heat release. At the surface, 106 W m−2of downwelling radiation is balanced by turbulent heat transfer to within a residual heat flux into the oceans of 0.45 W m−2, consistent with recent observations of changes in ocean heat content. Annual mean energy budgets and their seasonal cycles for each of seven continents and nine ocean basins are also presented.