MERIDIONAL ENERGY-TRANSPORT - UNCERTAINTY IN ZONAL MEANS

The meridional energy transport in the atmosphere and ocean is compute d using atmospheric analyses from ECMWF and NMC, and net radiative flu x from ERBE. An error analysis of the zonally-averaged total transport shows that errors of +/-7 Wm(-2) in net flux produce transport errors of +/-0.5 PW at the equator, an error of +/-9% in midlatitudes. Metho ds for correcting the mass non-conservation in transports derived from operational analyses are discussed. The ECMWF and NMC analysis system s now show remarkably similar zonally-averaged total energy transports , with normalized RMS differences of only 11%, despite 23% differences in Hadley-cell transports. The implied oceanic transport is derived a long with an error estimate, and it is found to be broadly consistent with more direct measures of oceanic transport. The energy transport i n NCAR's CCM1 and CCM2 is computed and is found to be about 20% larger than observations.