Toward a discrimination between anthropogenic and natural nanoparticles of atmospheric origin entrapped in ancient glacier ice
Abstract
Atmospheric mineral nanoparticles entrapped in ancient ice from remote areas are just starting to be explored as, until recently, the size of this class of glacial particles was below the detection limit of the conventional techniques used for dust analysis. These particles, smaller than 200 nanometers, could influence the atmospheric radiative balance directly, by scattering and absorbing the solar radiation, and indirectly by acting as ice nucleating particles that in turn influence the planetary albedo. Recent technological and industrial development is introducing a large number of natural and engineered nanoparticles into Earth's atmosphere. These constitute a concern for the human health, mainly due to their very high chemical reactivity. While many atmospheric nanoparticle studies have been performed in modern urban environments, there is essentially no information about their occurrence in a pristine atmosphere. This is critical, as it constitutes an important benchmark of comparison for the modern, anthropogenically affected atmosphere. We have identified and geochemically characterized atmospheric mineral nanoparticles entrapped in several modern and prehistorical ice samples collected from high elevation in the European Alps (Mt. Ortles 3869 m) and in pre-industrial ice sections from the "horizontal ice core" from the remote Taylor Glacier (coastal East Antarctica). A unique set of techniques is employed including Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX), Single Particle Inductively Coupled Plasma Quadrupole Mass Spectrometry (spICP-QMS), spICP-Time of Flight MS to determine mineral nanoparticle sizes, number/volume and chemical composition. We discuss the characterization of these atmospheric nanoparticles from very distinct periods and areas of the world in the context of a potential discrimination of nanoparticles of anthropogenic and natural origin with the aim of identifying new proxies of the Anthropocene.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC046.0009G
- Keywords:
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- 3344 Paleoclimatology;
- ATMOSPHERIC PROCESSES;
- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0724 Ice cores;
- CRYOSPHERE;
- 0726 Ice sheets;
- CRYOSPHERE