Impacts of post-depositional processing on nitrate isotopes in the snow and the overlying atmosphere at Summit, Greenland

• Published in: The Cryosphere
• Main Authors: Z. Jiang, J. Savarino, B. Alexander, J. Erbland, J.-L. Jaffrezo, L. Geng
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2022
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Greenland; ice core; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-16-2709-2022; https://doaj.org/article/36ff80d0eb184466af2555c3e18925b6

The effect of post-depositional processing on the preservation of snow nitrate isotopes at Summit, Greenland, remains a subject of debate and is relevant to the quantitative interpretation of ice-core nitrate (isotopic) records at high snow accumulation sites. Here we present the first year-round observations of atmospheric nitrate and its isotopic compositions at Summit and compare them with published surface snow and snowpack observations. The atmospheric δ 15 N(NO <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="53e1f98be2cdf70dbe180d95894fc6b5"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-16-2709-2022-ie00001.svg" width="9pt" height="16pt" src="tc-16-2709-2022-ie00001.png"/></svg:svg> ) remained negative throughout the year, ranging from − 3.1 ‰ to − 47.9 ‰ with a mean of ( − 14.8 ± 7.3) ‰ ( n =54 ), and displayed minima in spring which are distinct from the observed spring δ 15 N(NO <math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><msubsup><mi/><mn mathvariant="normal">3</mn><mo>-</mo></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="9pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="1933cd4f78557ae19e1c84fa4d0b5473"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-16-2709-2022-ie00002.svg" width="9pt" height="16pt" src="tc-16-2709-2022-ie00002.png"/></svg:svg> ) maxima in snowpack. The spring average atmospheric δ 15 N(NO <math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" ...