Sunlight-driven nitrate loss records Antarctic surface mass balance

• Published in: Nature Communications
• Main Authors: Akers, Pete, Savarino, Joël, Caillon, Nicolas, Servettaz, Aymeric, Le Meur, Emmanuel, Magand, Olivier, Martins, Jean, Agosta, Cécile, Crockford, Peter, Kobayashi, Kanon, Hattori, Shohei, Curran, Mark, van Ommen, Tas, Jong, Lenneke, Roberts, Jason
• Other Authors: Université Grenoble Alpes (UGA), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), ANR-16-CE01-0011,EAIIST,Projet International d'exploration de la calotte polaire de l'Antarctique de l'Est(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE.MCG]Environmental Sciences/Global Changes; Antarc*; Antarctic; Antarctica; East Antarctica; ice core
• Online Access: https://hal.science/hal-03877291; https://hal.science/hal-03877291/document; https://hal.science/hal-03877291/file/Akers-2022-Sunlight-driven-nitrate-loss-record.pdf; https://doi.org/10.1038/s41467-022-31855-7

International audience Abstract Standard proxies for reconstructing surface mass balance (SMB) in Antarctic ice cores are often inaccurate or coarsely resolved when applied to more complicated environments away from dome summits. Here, we propose an alternative SMB proxy based on photolytic fractionation of nitrogen isotopes in nitrate observed at 114 sites throughout East Antarctica. Applying this proxy approach to nitrate in a shallow core drilled at a moderate SMB site (Aurora Basin North), we reconstruct 700 years of SMB changes that agree well with changes estimated from ice core density and upstream surface topography. For the under-sampled transition zones between dome summits and the coast, we show that this proxy can provide past and present SMB values that reflect the immediate local environment and are derived independently from existing techniques.