A study conducted on the planetary system's heating energy revealed an inconsistency when comparing data from satellites with measurements of how much Earth's oceans were heating. The mystery was just resolved in a new NASA investigation.
The previous study was compiled by experts at the Boulder, Colorado-based National Center for Atmospheric Research (NCAR), two years ago. One of the questions that immediately sprung to mind was whether experts were misinterpreting data on how much solar heat was absorbed and emitted.
Like all systems, Earth too has an energy balance, which is primarily driven by the Sun and, to a less significant extent, by heat coming from its core. When solar heat hits the planet, some of it is absorbed – and contributes to heating Earth – whereas the remaining portion is reflected back into space.
Therefore, when the NCAR study released its conclusions, scientists were puzzled to find discrepancies in the two datasets. An international collaboration of experts was immediately set up to investigate the weird readings.
The group included oceanographers and atmospheric scientists, and was led by NASA Langley Research Center expert Normal Loeb. The team included Jet Propulsion Laboratory
(JPL) scientist Graeme Stephens. The data the team used for the research covered the decade between 2001 and 2010.
The Clouds and the Earth's Radiant Energy System Experiment (CERES) orbital instruments played a critical role in this study, since they were specifically built to measure changes in the net radiation balance at the top of Earth's atmosphere.
Once observational uncertainties are taken into account, the satellite and ocean measurements are actually pretty closely tied, says the research team. Full details of its work appear in the January 22 issue of the top journal Nature Geosciences.
“One of the things we wanted to do was a more rigorous analysis of the uncertainties. When we did that, we found the conclusion of missing energy in the system isn't really supported by the data,” Loeb explains.
“Our data show that Earth has been accumulating heat in the ocean at a rate of half a watt per square meter (10.8 square feet), with no sign of a decline. This extra energy will eventually find its way back into the atmosphere and increase temperatures on Earth,” the expert concludes.