Abstract
Satellite, reanalysis, and ocean in situ data are analyzed to evaluate
regional, hemispheric and global mean trends in Earth’s energy fluxes
during the first twenty years of the 21st century.
Regional trends in net top-of-atmosphere (TOA) radiation from the Clouds
and the Earth’s Radiant Energy System (CERES), ECMWF Reanalysis 5
(ERA5), and a model similar to ERA5 with prescribed sea surface
temperature (SST) and sea ice differ markedly, particularly over the
Eastern Pacific Ocean, where CERES observes large positive trends.
Hemispheric and global mean net TOA flux trends for the two reanalyses
are smaller than CERES, and their climatological means are half those of
CERES in the southern hemisphere (SH) and more than nine times larger in
the northern hemisphere (NH). The regional trend pattern of the
divergence of total atmospheric energy transport (TEDIV) over ocean
determined using ERA5 analyzed fields is similar to that inferred from
the difference between TOA and surface fluxes from ERA5 short-term
forecasts. There is also agreement in the trend pattern over ocean for
surface fluxes inferred as a residual between CERES net TOA flux and
ERA5 analysis TEDIV and surface fluxes obtained directly from ERA5
forecasts. Robust trends are observed over the Gulf Stream associated
with enhanced surface-to-atmosphere transfer of heat. Within the ocean,
larger trends in ocean heating rate are found in the NH than the SH
after 2005, but the magnitude of the trend varies greatly among
datasets.