HR: 09:00h
AN: A51D-05 [Abstracts]
TI: The Annual Cycle of the Energy Budget: Global mean and Land-Ocean Exchanges
AU: * Trenberth, K E
EM: trenbert@ucar.edu
AF: NCAR, PO Box 3000, Boulder, CO 80307, United States
AU: Fasullo, J T
EM: fasullo@ucar.edu
AF: NCAR, PO Box 3000, Boulder, CO 80307, United States
AB:
The mean and annual cycle of energy flowing into the climate system and its storage, release, and transport in
the atmosphere, ocean, and land surface are estimated with recent observations. An emphasis is placed on
establishing internally consistent quantitative estimates with a full discussion and assessment of uncertainty. At
the top-of-atmosphere (TOA), adjusted Earth Radiation Budget Experiment (ERBE) and Clouds and the Earth's
Radiant Energy System (CERES) satellite retrievals are used, while in the atmosphere NCEP/NCAR and ECMWF
reanalysis (ERA-40) estimates are used. The net upward surface flux (Fs) over ocean is derived from the residual
of TOA and atmospheric budgets, and is compared with direct calculations of ocean heat content (Oe) and its
tendency from several ocean temperature datasets. Over land Fs from a stand-alone simulation of the
Community Land Model forced by observed fields is used.
The near balance between net TOA radiation (R) and Fs over ocean and thus with Oe, and between R and
atmospheric total energy divergence over land, are documented both in the mean and for the annual cycle.
However, there is an annual mean transport of energy by the atmosphere from ocean to land regions of
2.2±0.1 PW primarily in the northern winter when the transport exceeds 5 PW. The global albedo is
dominated by a semiannual cycle over the oceans, but combines with the large annual cycle in solar insolation to
produce a peak in absorbed and net radiation in February, somewhat after the perihelion, and with the net
radiation 4.3 PW higher than the annual mean, as it is enhanced by the annual cycle of outgoing long-wave
radiation that is dominated by land regions. In situ estimates of the annual variation of Oe are found to be
unrealistically large.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1620 Climate dynamics (0429, 3309)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 1635 Oceans (1616, 3305, 4215, 4513)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly