Hi Alison, Here are the responses you requested...
> > (1) I don't understand what the definition of picophytoplankton > (carbon > > concentration from the picophytoplankton (<2 um; < 5um) component > > alone) means Does it mean cells between 2 and 5 um in size, in > which> case it should be expressed as 2-5um, or does it mean > something else? > > > > I agree that this definition doesn't make sense as it stands - I'll > check with John Dunne. The wishy-washiness of this definition was intended to account for the fact that some groups make their distinction of smallest phytoplankton class at the <2um size, while others do it at the <5um size. I agree that it would be better to have a single cut off for clarity. Perhaps we should use the '2um' designation to be consistent with the traditional definition of 'picoplankton' (where nanoplankton is the 2-5 umclass), and leave the individual participants to determine whether they think their definition is consistent with this designation. > > (3) 'mole_concenration_of_dissolved_iron_in_sea_water'. Besides the > > typo (concentration), does this refer to iron in all oxidation > states> (Fe2+/Fe3+) and chemical environments. If so, calling it > 'total iron' > > might be better. > > Thanks for pointing out the typo - I'll correct it. I think whenever > the word "total" has come up in standard names proposals in the past > that we have tried to avoid using it. Indeed, there are no standard > names that use the term. I think "iron" essentially should be > understood to mean "total iron" and if we want more specific names for > Fe2+, etc, we should introduce terms such as "divalent iron" in the > waythat we have done for elemental and divalent mercury in the > atmosphere.Having said all that, I think it would be helpful if > John could clarify > the definition. In the geochemical literature, 'total' iron refers to the sum of iron associated with the particulate organic, particulate inorganic, dissolved organic and dissolved inorganic components (both Fe2+ and Fe3+). As we treat phytoplankton iron and particulate detrital iron separately from dissolved, 'total' does not equal 'dissolved'. As most, if not all, of the models do not distinguish between Fe2+ and Fe3+, I think we could simply add a note in the definition to the effect that 'dissolved' is intended to represent both Fe2+ and Fe3+. Cheers, John _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
