What has caused the secular increase in solar nitrogen-15?
Well-documented variations in the (15)N/(14)N ratio in lunar surface samples apparently result from a secular increase in that ratio in the solar wind during the past few billion years. The cause of this change seems to lie in the solar convective zone but is inexplicable within our present understanding of solar processes. This problem therefore ranks with the solar neutrino deficiency as a major challenge to our solar paradigm.
Kerridge
J F
JF