Abstract
Smart et al. (2014) suggested that the detection of nitrate spikes in polar ice cores from solar energetic particle (SEP) events could be achieved if an analytical system with sufficiently high resolution was used. Here we show that the spikes they associate with SEP events are not reliably recorded in cores from the same location, even when the resolution is clearly adequate. We explain the processes that limit the effective resolution of ice cores. Liquid conductivity data suggest that the observed spikes are associated with sodium or another nonacidic cation, making it likely that they result from deposition of sea salt or similar aerosol that has scavenged nitrate, rather than from a primary input of nitrate in the troposphere. We consider that there is no evidence at present to support the identification of any spikes in nitrate as representing SEP events. Although such events undoubtedly create nitrate in the atmosphere, we see no plausible route to using nitrate spikes to document the statistics of such events.
Department
Earth Systems Research Center
Publication Date
3-4-2016
Journal Title
Journal of Geophysical Research: Space Physics
Publisher
American Geophysical Union (AGU)
Digital Object Identifier (DOI)
Document Type
Commentary
Recommended Citation
Wolff, E. W., M. Bigler, M. A. J. Curran, J. E. Dibb, M. M. Frey, M. Legrand, and J. R. McConnell (2016), Comment on “Low time resolution analysis of ice cores cannot detect impulsive nitrate events” by D. F. Smart et al., Journal of Geophysical Research – Space Physics, 1920-1924, https://dx.doi.org/10.1002/2015JA021570
Rights
©2016. American Geophysical Union. All Rights Reserved.
Comments
This is an article published by AGU in Y in Z, available online: https://dx.doi.org/10.1002/2015JA021570