Influence of Changes in pH and Temperature on the Distribution of Apparent Iron Solubility in the Oceans

Zhu，Kechen1,2; Achterberg，Eric P.1; Bates，Nicholas R.3,4; Gerringa，Loes J.A.5; Middag，Rob5,6; Hopwood，Mark J.7; Gledhill，Martha1

2023-05-01

10.1029/2022GB007617

Global Biogeochemical Cycles   影响因子和分区

0886-6236

1944-9224

An insufficient supply of the micronutrient iron (Fe) limits phytoplankton growth across large parts of the ocean. Ambient Fe speciation and solubility are largely dependent on seawater physico-chemical properties. We calculated the apparent Fe solubility (SFe(III)) at equilibrium for ambient conditions, where SFe(III) is defined as the sum of aqueous inorganic Fe(III) species and Fe(III) bound to organic matter formed at a free Fe concentration equal to the solubility of Fe hydroxide. We compared the SFe(III) to measured dissolved Fe (dFe) in the Atlantic and Pacific Oceans. The SFe(III) was overall ∼2–4-fold higher than observed dFe at depths less than 1,000 m, ∼2-fold higher than the dFe between 1,000 and 4,000 m and ∼3-fold higher than dFe below 4,000 m. Within the range of used parameters, our results showed that there was a similar trend in the vertical distributions of horizontally averaged SFe(III) and dFe. Our results suggest that vertical dFe distributions are underpinned by changes in SFe(III), which are driven by relative changes in ambient pH and temperature. Since both pH and temperature are essential parameters controlling ambient Fe speciation, these should be accounted for in investigations of changing Fe dynamics, particularly in the context of ocean acidification and warming.

Atlantic Ocean dissolved organic carbon iron biogeochemistry iron speciation ocean acidification organic matter Pacific Ocean

SCI

英语

通讯

UK National Environmental Research Council[GL 807/2-1] ; null[NE/G015732/1]

Environmental Sciences & Ecology ; Geology ; Meteorology & Atmospheric Sciences

Environmental Sciences ; Geosciences, Multidisciplinary ; Meteorology & Atmospheric Sciences

WOS:001000101700001

AMER GEOPHYSICAL UNION

GEOSCIENCES

2-s2.0-85160411896

Scopus

1.GEOMAR Helmholtz Center for Ocean Research Kiel,Kiel,Germany
2.Now at Southern University of Science and Technology,Shenzhen,China
3.Bermuda Institute of Ocean Science,St. George's,Bermuda
4.Department of Ocean and Earth Science,National Oceanography Center,University of Southampton,Southampton,United Kingdom
5.Department of Ocean Systems,NIOZ,Royal Netherlands Institute for Sea Research,Texel,Netherlands
6.Department of Geology and Centre for Trace Element Analysis,University of Otago,Dunedin,New Zealand
7.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,China

Zhu，Kechen,Achterberg，Eric P.,Bates，Nicholas R.,et al. Influence of Changes in pH and Temperature on the Distribution of Apparent Iron Solubility in the Oceans[J]. Global Biogeochemical Cycles,2023,37(5).

Zhu，Kechen.,Achterberg，Eric P..,Bates，Nicholas R..,Gerringa，Loes J.A..,Middag，Rob.,...&Gledhill，Martha.(2023).Influence of Changes in pH and Temperature on the Distribution of Apparent Iron Solubility in the Oceans.Global Biogeochemical Cycles,37(5).

Zhu，Kechen,et al."Influence of Changes in pH and Temperature on the Distribution of Apparent Iron Solubility in the Oceans".Global Biogeochemical Cycles 37.5(2023).