|dc.contributor.author||Gonçalves Ageitos, María
|dc.contributor.author||Pérez García-Pando, Carlos
|dc.identifier.citation||Bergas-Massó, E.; Gonçalves Ageitos, M.; Pérez García-Pando, C. Sensitivity of soluble iron deposition to soil mineralogy uncertainty. A: . Barcelona Supercomputing Center, 2021, p. 75-77.
|dc.description.abstract||Mineral dust emitted from arid and semi-arid areas has
several effects on the Earth system (e.g., perturbation of the
radiative budget, interaction with cloud processes, implications
on ocean and land biogeochemical cycles). Mineral dust
aerosols are mixtures of different minerals whose relative abundances,
particle size distribution, shape, surface topography,
and mixing state influence their interaction with the Earth
system. However, Earth System Models (ESMs) typically
assume that dust aerosols have a globally uniform composition,
neglecting the known variations in the sources’ mineralogical
composition. This work investigates the sensitivity of a key
biogeochemical cycle, the iron (Fe) cycle to uncertainties in
the description of soil mineralogy in dust-producing areas.
Airborne mineral dust is the primary input of Fe to the open
ocean. Fe constitutes a fundamental micro-nutrient for marine
biota in its soluble form. It is, in fact, the limiting nutrient
in remote regions of the open ocean known as High Nutrient
Low-Chlorophyll (HNLC) regions (e.g., the Southern Ocean),
where the Fe supply occurs mainly through atmospheric deposition.
Ocean productivity relies on the availability of limiting
nutrients. Hence, the ocean’s ability to capture atmospheric
CO2 in HNLC regions highly depends on the atmospheric
deposition of soluble Fe.
Fe abundance in soils is usually set to 3.5% , and its
solubility is considered to be less than 0.1% . However,
both observations and modeling studies suggest that the solubility
of Fe from dust increases downwind of the sources .
A primary mechanism leading to this increase in Fe solubility
is acidic (proton-promoted) dissolution. Low pH conditions in
aerosol water favor Fe dissolution by weakening Fe-O bonds of
Fe oxides in dust . Other physical and chemical mechanisms
that enhance Fe solubilization involve photochemical reduction
and organic ligand (e.g., Oxalate) processing .
Modeling the global dust mineralogical composition
presents critical challenges. First, soil mineralogy atlases for
dust modeling are derived by extrapolating a sparse set of
mineralogical analyses of soil samples that are particularly
scarce in dust source regions. Moreover, atlases are based on
measurements following the wet sieving technique that tampers
the undisturbed parent soil size distribution by breaking coarse
particles and replacing them with smaller ones .
In this work, we assess the implications of soil mineralogy
uncertainties on bio-available Fe delivery to the open
ocean by using a state-of-the-art ESM, EC-Earthv3, where a
detailed atmospheric Fe cycle and two different data sets that
characterize the soil composition over dusty areas have been
implemented  .
|dc.publisher||Barcelona Supercomputing Center
|dc.subject||Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors
|dc.subject.lcsh||High performance computing
|dc.title||Sensitivity of soluble iron deposition to soil mineralogy uncertainty
|dc.subject.lemac||Càlcul intensiu (Informàtica)