# Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”

Morgane Perron, Susanne Fietz, Douglas Hamilton, Akinori Ito, Rachel Shelley, Mingjin Tang

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## ► To cite this version:

Morgane Perron, Susanne Fietz, Douglas Hamilton, Akinori Ito, Rachel Shelley, et al.. Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”. Atmospheric Measurement Techniques, 2024, 17 (1), pp.165-166. 10.5194/amt-17-165-2024. hal-04505586

HAL Id: hal-04505586

https://hal.univ-brest.fr/hal-04505586

Submitted on 16 Mar 2024

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# Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”

Morgane Perron, Susanne Fietz, Douglas Hamilton, Akinori Ito, Rachel Shelley, Mingjin Tang

<figure><img src="image_1.png" /></figure>

## ► To cite this version:

Morgane Perron, Susanne Fietz, Douglas Hamilton, Akinori Ito, Rachel Shelley, et al.. Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”. Atmospheric Measurement Techniques, 2024, 17 (1), pp.165-166. 10.5194/amt-17-165-2024. hal-04505586

HAL Id: hal-04505586

https://hal.univ-brest.fr/hal-04505586v1

Submitted on 16 Mar 2024

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_3.png" /></figure>

# Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”

Morgane M. G. Perron<fnref n="1" />, Susanne Fietz<fnref n="2" />, Douglas S. Hamilton<fnref n="3" />, Akinori Ito<fnref n="4" />, Rachel U. Shelley<fnref n="5" />, and Mingjin Tang<fnref n="6" />

**Correspondence:** Morgane M. G. Perron (morgane.perron@univ-brest.fr)

Published: 12 January 2024

Marine primary production and export production are responsible for the capture of 25%–35% of the carbon emitted to the atmosphere by human activities, thereby partially mitigating the anthropogenic forcing on climate. The acquisition of carbon, nitrogen, and phosphorus by marine phytoplankton and bacteria relies, in part, on the availability of micronutrient trace elements such as iron, manganese, and zinc. On the other hand, elevated concentrations of potentially toxic trace elements such as copper or lead can hinder the performance of these metabolic processes. The supply of aerosol trace elements to remote ocean regions therefore exerts a fundamental control on bacterial and primary production and, ultimately, on oceanic carbon dioxide sequestration. Via the same pathway, aeolian trace elements can also impact fisheries, and thus have a broad societal impact.

Increased ocean stratification in the context of a warming climate is projected to decrease the internal supply of trace nutrients in the surface ocean. Hence, it becomes essential to accurately predict the external atmospheric trace nutrient load and properties using a combination of observations and global numerical models. One key aspect of the atmospheric trace nutrient supply to the ocean is that the estimated bioaccessibility of the deposited elements differs vastly between studies. While dust is the largest contributor to trace element atmospheric loading globally, anthropogenic and wildfire aerosols often contain a larger fraction of bioaccessible

micronutrients, due to differences in particle size, mineralogy, and solubility-enhancing reactions with acidic and organic compounds in the atmosphere (and present in surface seawater). For this reason, it becomes essential to accurately predict the magnitude, timing, and location of aeolian deposition fluxes (be they nutrients or toxic elements) in tandem with the associated response of the marine ecosystem.

Climate is responsible for the fast-evolving physical and biogeochemical conditions in the ocean. A first challenge with respect to assessing how much aerosol inputs modulate marine biogeochemical cycles is to determine atmospheric deposition rates to the open ocean at different locations and times. A further analytical challenge is that aerosol trace element solubility (the fraction of soluble to total) cannot be measured directly. Instead, a myriad of laboratory leaching experiments have been used to operationally define and report a large range of soluble aerosol trace element fractions in the literature. Such variability makes it exceptionally challenging to compare solubilities between different studies and to relate that solubility back to natural phenomena occurring at the collection site and upwind of it. The resulting operational uncertainty introduced into modelling studies that use these observations as verification is currently unquantified, hindering an accurate representation of soluble aeolian trace element fluxes to surface waters and the associated response of marine productivity. For example, aerosol Fe solubility

<footnote n="1">¹UMR 6539 CNRS/UBO/IRD/Ifremer, Laboratoire des sciences de l'environnement marin (LEMAR), Université de Brest – Institut Universitaire Européen de la Mer, 29280 Plouzané, France</footnote>

<footnote n="2">²Department of Earth Sciences, Stellenbosch University, 7600 Stellenbosch, South Africa</footnote>

<footnote n="3">³Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA</footnote>

<footnote n="4">⁴Yokohama Institute for Earth Sciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001, Japan</footnote>

<footnote n="5">⁵Department of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK</footnote>

<footnote n="6">⁶State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China</footnote>
<figure><img src="image_3.png" /></figure>

# Preface to the inter-journal special issue “RUSTED: Reducing Uncertainty in Soluble aerosol Trace Element Deposition”

Morgane M. G. Perron<fnref n="1" />, Susanne Fietz<fnref n="2" />, Douglas S. Hamilton<fnref n="3" />, Akinori Ito<fnref n="4" />, Rachel U. Shelley<fnref n="5" />, and Mingjin Tang<fnref n="6" />

**Correspondence:** Morgane M. G. Perron (morgane.perron@univ-brest.fr)

Published: 12 January 2024

Marine primary production and export production are responsible for the capture of 25%–35% of the carbon emitted to the atmosphere by human activities, thereby partially mitigating the anthropogenic forcing on climate. The acquisition of carbon, nitrogen, and phosphorus by marine phytoplankton and bacteria relies, in part, on the availability of micronutrient trace elements such as iron, manganese, and zinc. On the other hand, elevated concentrations of potentially toxic trace elements such as copper or lead can hinder the performance of these metabolic processes. The supply of aerosol trace elements to remote ocean regions therefore exerts a fundamental control on bacterial and primary production and, ultimately, on oceanic carbon dioxide sequestration. Via the same pathway, aeolian trace elements can also impact fisheries, and thus have a broad societal impact.

Increased ocean stratification in the context of a warming climate is projected to decrease the internal supply of trace nutrients in the surface ocean. Hence, it becomes essential to accurately predict the external atmospheric trace nutrient load and properties using a combination of observations and global numerical models. One key aspect of the atmospheric trace nutrient supply to the ocean is that the estimated bioaccessibility of the deposited elements differs vastly between studies. While dust is the largest contributor to trace element atmospheric loading globally, anthropogenic and wildfire aerosols often contain a larger fraction of bioaccessible

micronutrients, due to differences in particle size, mineralogy, and solubility-enhancing reactions with acidic and organic compounds in the atmosphere (and present in surface seawater). For this reason, it becomes essential to accurately predict the magnitude, timing, and location of aeolian deposition fluxes (be they nutrients or toxic elements) in tandem with the associated response of the marine ecosystem.

Climate is responsible for the fast-evolving physical and biogeochemical conditions in the ocean. A first challenge with respect to assessing how much aerosol inputs modulate marine biogeochemical cycles is to determine atmospheric deposition rates to the open ocean at different locations and times. A further analytical challenge is that aerosol trace element solubility (the fraction of soluble to total) cannot be measured directly. Instead, a myriad of laboratory leaching experiments have been used to operationally define and report a large range of soluble aerosol trace element fractions in the literature. Such variability makes it exceptionally challenging to compare solubilities between different studies and to relate that solubility back to natural phenomena occurring at the collection site and upwind of it. The resulting operational uncertainty introduced into modelling studies that use these observations as verification is currently unquantified, hindering an accurate representation of soluble aeolian trace element fluxes to surface waters and the associated response of marine productivity. For example, aerosol Fe solubility

<footnote n="1">¹UMR 6539 CNRS/UBO/IRD/Ifremer, Laboratoire des sciences de l'environnement marin (LEMAR), Université de Brest – Institut Universitaire Européen de la Mer, 29280 Plouzané, France</footnote>

<footnote n="2">²Department of Earth Sciences, Stellenbosch University, 7600 Stellenbosch, South Africa</footnote>

<footnote n="3">³Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA</footnote>

<footnote n="4">⁴Yokohama Institute for Earth Sciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001, Japan</footnote>

<footnote n="5">⁵Department of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK</footnote>

<footnote n="6">⁶State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China</footnote>
data reported in the literature range between 0.001 % and 100 %. As the uncertainty in the aeolian solubility reported for a number of other aerosol trace elements is just as large, it is now essential to disentangle the relative contribution of each factor to such uncertainty.

Through this special issue, the Scientific Commit-
tee on Oceanic Research Working Group 167 (SCOR
WG167, https://scor-int.org/group/reducing-uncertainty-
in-soluble-aerosol-trace-element-deposition-rusted/, last
access: 11 January 2024) wishes to gather a collection of
cutting-edge scientific studies with the following common
goal: Reduce the Uncertainty in Soluble aerosol Trace
Element Deposition (RUSTED) (Shelley et al., 2024). Since
2 November 2023, we have invited the international com-
munity to submit high-quality studies aimed at advancing
our understanding of the sources, atmospheric processing,
and deposition fluxes to the ocean and the impacts of aeolian
trace elements on ocean marine biogeochemical cycles – in
the past, present, or future. This special issue may contain
interdisciplinary research from field observations, laboratory
experiments, and numerical modelling studies.

The scope of this special issue is important and timely,
as it addresses several UN Ocean Decade challenges (e.g.
challenges 5 and 7) and aligns with current research prior-
ities of large international programmes, including the Sur-
face Ocean Lower Atmosphere Study (SOLAS, https://www.
solas-int.org, last access: 11 January 2024), GEOTRACES
(https://www.geotraces.org, last access: 11 January 2024),
and the joint Group of Experts on the Scientific Aspects
of Marine Environmental Protection (GESAMP, http://www.
gesamp.org, last access: 11 January 2024). This Coperni-
cus inter-journal special issue is an initiative of the SCOR
WG167 that is led by the *Atmospheric Measurement Tech-
niques* (AMT) journal and supported by the *Aerosol Re-
search* (AR), *Atmospheric Chemistry and Physics* (ACP),
and *Biogeosciences* (BG) journals.

We acknowledge the joint effort of the 20 members in-
volved in the working group. We wish to thank SCOR for
supporting the WG167 as well as Copernicus journals for
supporting this special issue.

References

Shelley, R., Perron, M. M. G., Hamilton, D. S., and Ito, A.: Every
(other) breath you take, Eos, in review, 2024.
data reported in the literature range between 0.001 % and 100 %. As the uncertainty in the aeolian solubility reported for a number of other aerosol trace elements is just as large, it is now essential to disentangle the relative contribution of each factor to such uncertainty.

Through this special issue, the Scientific Commit-
tee on Oceanic Research Working Group 167 (SCOR
WG167, https://scor-int.org/group/reducing-uncertainty-
in-soluble-aerosol-trace-element-deposition-rusted/, last
access: 11 January 2024) wishes to gather a collection of
cutting-edge scientific studies with the following common
goal: Reduce the Uncertainty in Soluble aerosol Trace
Element Deposition (RUSTED) (Shelley et al., 2024). Since
2 November 2023, we have invited the international com-
munity to submit high-quality studies aimed at advancing
our understanding of the sources, atmospheric processing,
and deposition fluxes to the ocean and the impacts of aeolian
trace elements on ocean marine biogeochemical cycles – in
the past, present, or future. This special issue may contain
interdisciplinary research from field observations, laboratory
experiments, and numerical modelling studies.

The scope of this special issue is important and timely,
as it addresses several UN Ocean Decade challenges (e.g.
challenges 5 and 7) and aligns with current research prior-
ities of large international programmes, including the Sur-
face Ocean Lower Atmosphere Study (SOLAS, https://www.
solas-int.org, last access: 11 January 2024), GEOTRACES
(https://www.geotraces.org, last access: 11 January 2024),
and the joint Group of Experts on the Scientific Aspects
of Marine Environmental Protection (GESAMP, http://www.
gesamp.org, last access: 11 January 2024). This Coperni-
cus inter-journal special issue is an initiative of the SCOR
WG167 that is led by the *Atmospheric Measurement Tech-
niques* (AMT) journal and supported by the *Aerosol Re-
search* (AR), *Atmospheric Chemistry and Physics* (ACP),
and *Biogeosciences* (BG) journals.

We acknowledge the joint effort of the 20 members in-
volved in the working group. We wish to thank SCOR for
supporting the WG167 as well as Copernicus journals for
supporting this special issue.

References

Shelley, R., Perron, M. M. G., Hamilton, D. S., and Ito, A.: Every
(other) breath you take, Eos, in review, 2024.