1. L06 Part I
Previously: Metal speciation theory and biological cellular uptake theory
Today: Connecting speciation and cellular uptake in the marine water column,
and several generations of iron modeling
Return to theme of introduction lecture:
What are the processes controlling the distribution of hybrid type metals?
How should they be parameterized in models?
Do we have enough data yet?

2. Iron as a limiting nutrient in HNLC regions (Review of Iron Fertilization Experiments Boyd et al., 2007, Science)
Purposeful (white crosses) and natural (red crosses) Fe enrichment studies have shown Fe limitation of phytoplankton growth.

3. Studies integrating iron modeling
1D – vertical profiles, no horizontal processes (Johnson 1997; Weber et al., 2007)
2D – GEOTRACES sections, horizontal processes
3D – GCM with iron (Fung, 2000; Archer and Johnson, Moore et al, 2002, 2004; Oschilles, Moore and Braucher 2008)

7. Fe:C determined using AOU: 2-13 mmol Fe mol-1 C, constant value of 5 not correct

8. Available iron database in 1999

12. Based on the Martin Carbon Power Law: Modified for production of dissolved iron, where Q is cellular quota (Fe:C ratio), with first order Fe scavenging with a “ligand protection term” (Fesoly)

13. “Ligand Protection” from scavenging is standard in models now

16. 1D vs 2D
Noble and Saito, preliminary data

17. Vertical fluxes require a source of metal Another clue in relative importance of vertical versus horizontal processes is M:P ratios
If 1D processes dominate, Hybrid Metal:P correlations can be supported (metal and P are both subject to remineralization advection etc)
If 2D processes dominate, unclear how Hybrid Metal:P are maintained. Point sources of metal likely do not have stoichiometric additions of P as well.

19. Generations of iron modeling
Fung et al,. 2000

20. Parekh, Boyle, Fellows GBC
From Parekh, Fellows, Boyle Box-model study, sensitivity testing of ligand parameters
Parekh, Boyle, Fellows GBC

21. From Moore and Braucher 2008 BG

22. From Moore and Braucher 2008 BG

25. Colloidal = “dissolved” – soluble
FeL is in all fractions
Wu Boyle and Sunda, 2001

27. Further reading: Iron modeling studies
Johnson 1997
Inez Y. Fung,1 Stephanie K. Meyn,2 Ina Tegen,3 Scott C. Doney,4 Jasmin G. John,1 and James K. B. Bishop5 GBC 1999
Archer and Johnson GBC 2000
Moore et al.., 2002, 2004
Parakh, Fellows, Boyle, GBC 2004
Weber, Volker Oschilies Burchard, BG 2007
Moore and Braucher Biogeosciences, 2008 Sedimentary and mineral dust sources of iron to the world oceans.

28. Societal Implications and Applications?