Physical and biological controls on carbon cycling in the equatorial Pacific: US JGOFS EqPac process study
Murray, J.W., R.T. Barber, M.R. Roman, M.P. Bacon and R.A. Feely
Science , (266), 58-65, 1994)
The equatorial Pacific is the largest oceanic source of carbon dioxide to the atmosphere
and has been proposed to be a major site of organic carbon export to the deep sea. Study of
the chemistry and biology of this area from 170° to 95°W suggests that the
variability of remote winds in the western Pacific and tropical instability waves are the major
factors controlling chemical and biological variability. The reason is that most of the
biological production is based on recycled nutrients; only a few of the nutrients transported
to the surface by upwelling are taken up by photosynthesis. Biological cycling within the
euphotic zone is efficient, and the export of carbon fixed by photosynthesis is small. The fluxes
of carbon dioxide to the atmosphere and particulate organic carbon to the deep sea were
about 0.3 gigatons per year, and the production of dissolved organic carbon was about
three times as large. The data establish El Niño events as the main source of
interannual variability.