Exploring the role of snow metamorphism on the isotopic composition of the surface snow at EastGRIP

• Published in: The Cryosphere
• Main Authors: Harris Stuart, Romilly, Faber, Anne-Katrine, Wahl, Sonja, Hörhold, Maria, Kipfstuhl, Sepp, Vasskog, Kristian, Behrens, Melanie, Zuhr, Alexandra M., Steen-Larsen, Hans Christian
• Format: Text
• Language: English
• Published: 2023
• Subjects: Greenland; East Greenland; East Greenland Ice-core Project; Greenland ice core; Greenland Ice core Project; ice core
• Online Access: https://doi.org/10.5194/tc-17-1185-2023; https://tc.copernicus.org/articles/17/1185/2023/

Stable water isotopes from polar ice cores are invaluable high-resolution climate proxy records. Recent studies have aimed to improve our understanding of how the climate signal is stored in the stable water isotope record by addressing the influence of post-depositional processes on the isotopic composition of surface snow. In this study, the relationship between surface snow metamorphism and water isotopes during precipitation-free periods is explored using measurements of snow-specific surface area (SSA). Continuous daily SSA measurements from the East Greenland Ice Core Project site (EastGRIP) during the summer seasons of 2017, 2018 and 2019 are used to develop an empirical decay model to describe events of rapid decrease in SSA linked to snow metamorphism. We find that SSA decay during precipitation-free periods at the EastGRIP site is best described by the exponential equation <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi mathvariant="normal">SSA</mi><mo>(</mo><mi>t</mi><mo>)</mo><mspace width="0.125em" linebreak="nobreak"/><mo>=</mo><mspace linebreak="nobreak" width="0.125em"/><mo>(</mo><msub><mi mathvariant="normal">SSA</mi><mn mathvariant="normal">0</mn></msub><mspace width="0.125em" linebreak="nobreak"/><mo>-</mo><mspace linebreak="nobreak" width="0.125em"/><mn mathvariant="normal">22</mn><mo>)</mo><mspace linebreak="nobreak" width="0.125em"/><mo>⋅</mo><mspace width="0.125em" linebreak="nobreak"/><msup><mi>e</mi><mrow><mo>-</mo><mi mathvariant="italic">α</mi><mspace width="0.125em" linebreak="nobreak"/><mi>t</mi></mrow></msup><mspace width="0.125em" linebreak="nobreak"/><mo>+</mo><mspace width="0.125em" linebreak="nobreak"/><mn ...