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Effects of postdepositional processing on nitrogen isotopes of nitrate in the Greenland Ice Sheet Project 2 ice core
Author(s) -
Geng Lei,
Zatko Maria C.,
Alexander Becky,
Fudge T. J.,
Schauer Andrew J.,
Murray Lee T.,
Mickley Loretta J.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl064218
Subject(s) - ice core , holocene , greenland ice sheet , snow , ice sheet , geology , glacial period , physical geography , climatology , paleoclimatology , nitrate , deglaciation , groenlandia , oceanography , climate change , environmental science , geomorphology , geography , chemistry , organic chemistry
Records of ice core nitrate and its isotopes hold the potential to assess past atmospheric conditions regarding NO x and oxidant levels. However, relating such records to past atmospheric conditions requires a site‐specific understanding of the postdepositional processing of snow nitrate. We report δ 15 N(NO 3 − ) records from the Greenland Ice Sheet Project 2 (GISP2) ice core over major climate transitions. Model calculations and comparison with records of parameters influencing UV‐driven postdepositional processing of snow nitrate suggest that the observed variability in GISP2 δ 15 N(NO 3 − ) over major climate transitions is primarily driven by changes in the degree of postdepositional loss of snow nitrate. Estimates of the fractional loss of snow nitrate is (16–23)% in the Holocene and (45–53)% in the glacial period, suggesting a (41 ± 32)% lower nitrate depositional flux to Greenland during the glacial period relative to the Holocene.