1. Iron as a limiting nutrient in HNLC regions
Justification - bioactive 1
HNLC - due to lack of a bioactive metal - Fe
Controls carbon flux
Surface ocean nitrate data
Showing high-nutrient low-chlorophyll regions

2. Existing deep ocean Fe data
Despite importance: we know very little - Fe and other bioactive metals
All models tell us - only 20-30% of Fe supplied from dust
E.g. no data in Southern Ocean. If you want to know about Fe upwelled from depth in Southern Ocean - can’t do it
Fe data is scarce, particularly in the deep ocean, limited understanding of the Fe cycle
Stations with Fe concentrations at depths > 2000 m
(taken from GEOTRACES Science Plan 2006)
DataLimited for Fe

3. …compared to the micronutrients
Fe (nmol/kg)
Simply measuring a full ocean section of Fe like that for NO3 will tell us more about Fe cycle than we know today.
Atlantic Fe
Boyd and Ellwood, Nature Geoscience, 2010

4. …compared to the micronutrients
Fe (nmol/kg)
Simply measuring a full ocean section of Fe like that for NO3 will tell us more about Fe cycle than we know today.
Atlantic Fe
Boyd and Ellwood, Nature Geoscience, 2010

5. Iron control of Nitrogen Fixation (?)
Jickells et al., 2005;Moore et al., 2009