Transcript Monday_3_BarbeauICESOCC.pptx

Evolving views of iron supply and cycling
in the Southern Ocean
Kathy Barbeau, SIO
-
John Martin’s legacy
Sub-surface iron sources
Unknowns in iron chemistry
Cryosphere iron
Budgets
GEOTRACES
Summary, questions
Mesoscale Fe Fertilization in the Southern Ocean
Coale et al. Science 2004
Role of Sedimentary Fe
Natural Fe fertilization sites
in the Southern Ocean
Morris & Charette, DSRII 2013
Unknowns in Fe chemistry – Southern Ocean
Enhanced solubility of Fe at in-situ temperatures –
Schlosser et al., L&O 2012
Unknowns in Fe chemistry – Southern Ocean
Geographically
distinct solid-phase
Fe pools in the
Southern Ocean
von der Heyden et al.,
Science 2012
Unknowns in Fe chemistry – Southern Ocean
Fe in the cryosphere - icebergs
Ken Smith et al. 2007; 2011
Fe in the cryosphere - glaciers
dFe fluxes in μmoles/m2/day
Gerringa et al. DSRII 2012 – DynaLiFe project
Southern Ocean Fe Budgets – Atlantic Sector
De Jong et al. JGR 2012
Fe source contributions
to Fe inventory
vs. carbon export
Tagliabue et al. GRL 2014
Southern Ocean carbon
export dominated by
sediment Fe sources
Comparing Fe utilization to various modes of Fe supply
Boyd et al. JGR 2012
http://www.egeotraces.org/
GEOTRACES Sections
Summary and Questions
Views on Fe supply in the Southern Ocean are evolving from
dust-centric perspective to recognition of additional
sedimentary, hydrothermal, cyrospheric Fe sources.
- Relative impact of different sources on carbon export?
- Future trajectory of cryospheric Fe source?
- Climate change impacts on sedimentary, dust Fe sources?
- Controls on Fe recycling?
- In situ Fe chemistry?