Particle-field estimation global estimators

The amount of primary production carried out in the oceans each year has been estimated from ocean color satellite data and shipboard incubations to be 140 g C m for a total of 50-60 Pg C (4-5 Pmol C) hxed in the surface ocean each year (Shuskina, 1985 Martin et al, 1987 Field et al, 1998). This represents roughly half of the global annual 105 Pg C hxed each year (Field etal., 1998), despite the fact that marine phytoplankton comprise less than 1 % of the total photosynthehc biomass on Earth. Extrapolahon from Redheld ratios suggests the incorporation 0.6-0.8 Pmol N, 40-50 Tmol P into biogenic particles each year in associahon with marine primary production. From the proportion of primary production carried out by diatoms and the average Si C raho of diatoms, silica production rates may be calculated to be 200-280 Tmol Si yr (Nelson et al, 1995 Treguer et al, 1995). 

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