  Ice cores are archives of climate change and possibly large solar proton
events (SPEs). Wolff et al. (2012) used a single event, a nitrate peak in the
GISP2-H core, which McCracken et al. (2001a) time associated with the poorly
quantified 1859 Carrington event, to discredit SPE-produced, impulsive nitrate
deposition in polar ice. This is not the ideal test case. We critique the Wolff
et al. analysis and demonstrate that the data they used cannot detect impulsive
nitrate events because of resolution limitations. We suggest re-examination of
the top of the Greenland ice sheet at key intervals over the last two millennia
with attention to fine resolution and replicate sampling of multiple species.
This will allow further insight into polar depositional processes on a
sub-seasonal scale, including atmospheric sources, transport mechanisms to the
ice sheet, post-depositional interactions, and a potential SPE association.
