Abstract
Nitrate ion spikes in polar ice cores are contentiously used to estimate the intensity, frequency, and probability of historical solar proton events, quantities that are needed to prepare for potentially society-crippling space weather events. We use the Whole Atmosphere Community Climate Model to calculate how large an event would have to be to produce enough odd nitrogen throughout the atmosphere to be discernible as nitrate peaks at the Earth's surface. These hypothetically large events are compared with probability of occurrence estimates derived from measured events, sunspot records, and cosmogenic radionuclides archives. We conclude that the fluence and spectrum of solar proton events necessary to produce odd nitrogen enhancements equivalent to the spikes of nitrate ions in Greenland ice cores are unlikely to have occurred throughout the Holocene, confirming that nitrate ions in ice cores are not suitable proxies for historical individual solar proton events.
Department
Earth Systems Research Center
Publication Date
4-20-2016
Journal Title
Journal of Geophysical Research: Atmospheres
Publisher
American Geophysical Union (AGU)
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
Duderstadt, K. A, J. E. Dibb, N. A. Schwadron, H. E. Spence, S. C. Solomon, V. A. Yudin, C. H. Jackman, and C. E. Randall (2016), Nitrate ions spikes in ice cores are not suitable proxies for solar proton events, Journal of Geophysical Research, 121, 2994–3016, https://dx.doi.org/10.1002/2015JD023805
Rights
©2016. American Geophysical Union. All Rights Reserved.
Comments
This is an article published by AGU in Journal of Geophysical Research: Atmospheres in 2016, available online: https://dx.doi.org/10.1002/2015JD023805