Has global phytoplankton biomass been estimated from satellite ocean color observations?  if so, what is the number.  Also, what is the global phytoplankton biomass if the regions of the continental shelves are excluded?

Thanks in advance.

William K. Dewar

william,
i am not currently aware of any credible estimates of global phytoplankton biomass based on ocean color data but that is not to say that they don't exist.  however, there have been a number of estimates of global ocean primary production based on ocean color data, one
of which can be found here:

http://www.sciencemag.org/content/vol291/issue5513/cover.shtml

regards,
gene

To expand on Gene's answer -- there is a good reason for the shortage of creditable biomass estimates for total (e.g., depth integrated) phytoplankton biomass.  The biomass vs depth profile is often modelled using a Gaussian plus a constant "background".  This is convenient for production but may be misleading if you integrate biomass to the same depth (e.g., 1% light) used in a production calculation.  Lack of light means the contribution to production from biomass at depth is tending to zero.  For production calculations getting the biomass right near the surface is important, but for total biomass one needs to be more confident of the value assigned for chl.
at depth.

Thank you, your replies have been most helpful.