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Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx
Published on: December 20, 2016
Nitrogen in solar energetic particles: isotopically distinct from solar wind
K J Mathew1, J F Kerridge, K Marti
1Department of Chemistry, University of California, San Diego, USA. mkattath@ucsd.edu
Geophysical Research Letters
|September 7, 2001
Summary
Solar energetic particles (SEP) deliver nitrogen (N) enriched in light 14N, unlike neon (Ne). This finding contrasts with existing models, suggesting unique solar source regions or acceleration mechanisms for different isotopes.
Area of Science:
- Cosmochemistry
- Planetary Science
- Astrochemistry
Background:
- Nitrogen and neon isotopic compositions in extraterrestrial samples provide insights into solar system processes.
- Previous studies on solar wind (SW) and solar energetic particle (SEP) nitrogen and neon isotopes have shown differing isotopic signatures.
Purpose of the Study:
- To investigate the isotopic composition of nitrogen implanted in lunar ilmenite grains.
- To compare the isotopic fractionation trends of nitrogen and neon from solar energetic particles and solar wind.
Main Methods:
- Stepwise etching of lunar soil ilmenite grains to analyze nitrogen isotopes at varying depths.
- Mass spectrometry to determine the 15N/14N ratios of implanted nitrogen.
Main Results:
- The 15N/14N ratio decreases with increasing implantation depth in ilmenite, indicating lower 15N/14N at higher energies.
- Nitrogen from solar energetic particles (N-SEP) is enriched in light 14N relative to solar-wind nitrogen (N-SW).
- This contrasts with neon (Ne-SEP), which is depleted in light 20Ne relative to Ne-SW.
Conclusions:
- The observed opposite isotopic fractionation trends for nitrogen and neon suggest distinct solar source regions or fractionation during particle acceleration.
- Current models do not fully explain the divergent isotopic fractionation patterns of N and Ne from solar energetic particles.
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