What controls the isotopic composition of Greenland surface snow?

• DOI: 10.5194/cp-10-377-2014
• Publication Date: 2014-02-20T13:40:32Z
• Authors: H. C. Steen-Larsen; V. Masson-Delmotte; M. Hirabayashi; R. Winkler; K. Satow; F. Prié; N. Bayou; E. Brun; K. M. Cuffey; D. Dahl-Jensen; M. Dumont; M. Guillevic; S. Kipfstuhl; A. Landais; T. Popp; C. Risi; K. Steffen; B. Stenni; A. E. Sveinbjörns...
• Keywords: δ18O; Ice core

Abstract. Water stable isotopes in Greenland ice core data provide key paleoclimatic information, and have been compared with precipitation isotopic composition simulated by isotopically enabled atmospheric models. However, post-depositional processes linked snow metamorphism remain poorly documented. For this purpose, monitoring of the (δ18O, δD) near-surface water vapor, samples top (0.5 cm) surface has conducted during two summers (2011–2012) at NEEM, NW Greenland. The also include a subset 17O-excess measurements over 4 days, span 2012 heat wave. Our observations are consistent calculations assuming equilibrium between vapor. We observe strong correlation vapor δ18O air temperature (0.85 ± 0.11‰ °C−1 (R = 0.76) for 2012). is not observed or data. Deuterium excess (d-excess) strongly anti-correlated stronger slope than During nine 1–5-day periods events, our demonstrate parallel changes d-excess similar larger those δ18O. It estimated using CROCUS model that 6 to 20% mass exchanged atmosphere. In data, sign related magnitude sublimation deposition. Comparisons models show day-to-day variations driven synoptic trajectories distillation histories. suggest that, these composition. This an 60% turnover per day recrystallization under NEEM summer gradients. findings implications interpretation model–data comparisons, call further process studies.