12 research outputs found
The WOCEâera 3âD Pacific Ocean circulation and heat budget
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Progress In Oceanography 82 (2009): 281-325, doi:10.1016/j.pocean.2009.08.002.To address questions concerning the intensity and spatial structure of the 3âdimensional
circulation within the Pacific Ocean and the associated advective and diffusive property flux
divergences, data from approximately 3000 highâquality hydrographic stations collected on
40 zonal and meridional cruises have been merged into a physically consistent model. The
majority of the stations were occupied as part of the World Ocean Circulation Experiment
(WOCE), which took place in the 1990s. These data are supplemented by a few preâWOCE
surveys of similar quality, and timeâaveraged directâvelocity and historical hydrographic
measurements about the equator.
An inverse box model formalism is employed to estimate the absolute alongâisopycnal
velocity field, the magnitude and spatial distribution of the associated diapycnal flow and
the corresponding diapycnal advective and diffusive property flux divergences. The resulting
largeâscale WOCE Pacific circulation can be described as two shallow overturning cells
at midâ to low latitudes, one in each hemisphere, and a single deep cell which brings abyssal
waters from the Southern Ocean into the Pacific where they upwell across isopycnals and
are returned south as deep waters. Upwelling is seen to occur throughout most of the basin
with generally larger dianeutral transport and greater mixing occurring at depth. The derived
pattern of ocean heat transport divergence is compared to published results based
on airâsea flux estimates. The synthesis suggests a strongly east/west oriented pattern of
airâsea heat flux with heat loss to the atmosphere throughout most of the western basins,
and a gain of heat throughout the tropics extending poleward through the eastern basins.
The calculated meridional heat transport agrees well with previous hydrographic estimates.
Consistent with many of the climatologies at a variety of latitudes as well, our meridional
heat transport estimates tend toward lower values in both hemispheres.This work was funded by National Science Foundation grants OCEâ9710102, OCEâ
9712209 and OCEâ0079383, and also benefited from work on closely related projects funded
by NSF grants OCEâ0223421 and OCEâ0623261, and NOAA grant NA17RJ1223 funded
through CICOR. For G.C.J. NASA funding came under Order Wâ19,314