Peter D Neff¹, Vasilii V Petrenko², David M Etheridge³, Andrew Milford Smith⁴, Edward Crosier², Benjamin Hmiel^2,5, David Thornton⁶, Lenneke M Jong⁷, Ross Beaudette⁸, Christina M Harth⁸, Ray Leonard Langenfelds³, Blagoj Mitrevski³, Mark Curran⁷, Christo Buizert⁹, Lee T Murray², Cathy M Trudinger³, Michael Dyonisius^10,11, Jessica Yi-Jun Ng¹², Jeffrey P Severinghaus¹² and Ray F Weiss¹³, (1)University of Minnesota Twin Cities, Department of Soil, Water, and Climate, Minneapolis, MN, United States, (2)University of Rochester, Department of Earth and Environmental Sciences, Rochester, NY, United States, (3)CSIRO, Oceans and Atmosphere, Aspendale, VIC, Australia, (4)Australian Nuclear Science and Technology Organisation (ANSTO), Kirrawee DC, Australia, (5)Environmental Defense Fund, Austin, TX, United States, (6)CSIRO, Aspendale, VIC, Australia, (7)Australian Antarctic Division, Kingston, TAS, Australia, (8)University of California San Diego, Scripps Institution of Oceanography, La Jolla, CA, United States, (9)Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, OR, United States, (10)University of Rochester, Department of Earth and Environmental Sciences, Rochester, United States, (11)Niels Bohr Institute, University of Copenhagen, Physics of Ice Climate and Earth, Copenhagen, Denmark, (12)Scripps Institution of Oceanography, La Jolla, CA, United States, (13)Univ California San Diego, La Jolla, CA, United States

Vasilii V Petrenko¹, Benjamin Hmiel^1,2, Michael Dyonisius^3,4, Andrew Milford Smith⁵, Peter D Neff^1,6 and Segev BenZvi⁷, (1)University of Rochester, Department of Earth and Environmental Sciences, Rochester, NY, United States, (2)Environmental Defense Fund, Austin, TX, United States, (3)University of Rochester, Department of Earth and Environmental Sciences, Rochester, United States, (4)Niels Bohr Institute, University of Copenhagen, Physics of Ice Climate and Earth, Copenhagen, Denmark, (5)Australian Nuclear Science and Technology Organisation (ANSTO), Kirrawee DC, Australia, (6)University of Minnesota Twin Cities, Department of Soil, Water, and Climate, Minneapolis, MN, United States, (7)University of Rochester, Department of Physics and Astronomy, Rochester, NY, United States

Michael Dyonisius^1,2, Benjamin Hmiel^3,4, Vasilii V Petrenko³, Janani Ventakesh⁵, Jochen Schmitt⁶ and Thomas Blunier⁷, (1)University of Rochester, Department of Earth and Environmental Sciences, Rochester, United States, (2)Niels Bohr Institute, University of Copenhagen, Physics of Ice Climate and Earth, Copenhagen, Denmark, (3)University of Rochester, Department of Earth and Environmental Sciences, Rochester, NY, United States, (4)Environmental Defense Fund, Austin, TX, United States, (5)Niels Bohr Institute, Physics of Ice Climate and Earth, København Ø, Denmark, (6)University of Bern, Oeschger Centre for Climate Change Research, Bern, Switzerland, (7)University of Copenhagen, Physics of Ice Climate and Earth, København Ø, Denmark

Giyoon Lee¹, Jinho Ahn², Hyeontae Joo³, Florian Ritterbusch⁴, Ikumi Oyabu⁵, Songyi Kim³, Kenji Kawamura^6,7, Zheng-Tian Lu⁸, Sangyoung Han⁹, Sambit Ghosh¹⁰, Yeongcheol Han³, Sangbum Hong¹¹, Changhee Han³, Soon Do Hur³, Wei Jiang⁸ and Guomin Yang¹², (1)Seoul National University, Seoul, Korea, Republic of (South), (2)Seoul National University, School of Earth and Environmental Sciences, Seoul, Korea, Republic of (South), (3)Korea Polar Research Institute, Incheon, South Korea, (4)University of Science and Technology of China (USTC), Hefei, China, (5)National Institute of Polar Research, Tokyo, Japan, (6)Natl. Inst. of Polar Research, Tokyo, Japan, (7)Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Kanagawa, Japan, (8)University of Science and Technology of China, Hefei, China, (9)Seoul National University, Seoul, South Korea, (10)Seoul National University, Earth Sciences, Seoul, South Korea, (11)KOPRI Korea Polar Research Institute, Incheon, Korea, Republic of (South), (12)University of Science and Technology of China, Hefei National Laboratory for Physical Sciences at Microscale, Hefei, China

Ilaria Crotti^1,2, Barbara Stenni¹, Amaelle Landais², Carlo Barbante³, Massimo Frezzotti⁴, Florian Ritterbusch⁵, Zheng-Tian Lu⁶, Anais J Orsi², Guo-Min Yang⁵, Wei Jiang⁶ and Lucie Bazin², (1)University of Venice, Venice, Italy, (2)LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (3)Ca' Foscari University, Department of Environmental Sciences, Informatics and Statistics, Venice, Italy, (4)University of Roma 3, Rome, Italy, (5)University of Science and Technology of China (USTC), Hefei, China, (6)University of Science and Technology of China, Hefei, China

Christo Buizert¹, Sarah Shackleton², Jeffrey P Severinghaus³, William Roberts⁴, Bernhard Bereiter³, Kenji Kawamura⁵, Daniel Baggenstos⁶, Anais Orsi⁷, Ikumi Oyabu⁸, Benjamin Birner³, Edward Brook⁹, David M Etheridge¹⁰, Nancy A.N. Bertler¹¹, Rebecca L. Pyne¹², Robert Mulvaney¹³ and Ellen Mosley-Thompson¹⁴, (1)Oregon State University, College of Ocean, Earth, and Atmospheric Sciences, Corvallis, OR, United States, (2)Princeton University, Princeton, NJ, United States, (3)Scripps Institution of Oceanography, La Jolla, CA, United States, (4)Northumbria University, Geography and Environmental Sciences, Newcastle-Upon-Tyne, United Kingdom, (5)Natl. Inst. of Polar Research, Tokyo, Japan, (6)University of Bern, Bern, Switzerland, (7)Université Paris-Saclay, Gif-sur-Yvette, France, (8)National Institute of Polar Research, Tokyo, Japan, (9)Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, OR, United States, (10)CSIRO, Oceans and Atmosphere, Aspendale, VIC, Australia, (11)Victoria University of Wellington and GNS Science, Antarctic Research Centre, Wellington, New Zealand, (12)GNS Science-Institute of Geological and Nuclear Sciences Ltd, Lower Hutt, New Zealand, (13)British Antarctic Survey, Cambridge, United Kingdom, (14)Ohio State University Main Campus, Department of Geography, Columbus, OH, United States

Murat Aydin¹, Melinda Renee Nicewonger^2,3, Erich C Osterberg⁴, Karl J Kreutz⁵, Dominic Winski⁵, David G Ferris Mr.⁴, Jihong Cole-Dai⁶, Zayta Renay Thundercloud⁴, Eric S Saltzman¹ and Armando Byron Vilchez⁷, (1)University of California Irvine, Irvine, CA, United States, (2)NOAA/ESRL Global Monitoring Laboratory, Boulder, CO, United States, (3)University of California, Irvine, Irvine, CA, United States, (4)Dartmouth College, Department of Earth Sciences, Hanover, NH, United States, (5)University of Maine, School of Earth and Climate Sciences, Orono, ME, United States, (6)South Dakota State University, Department of Chemistry and Biochemistry, Brookings, SD, United States, (7)University of California Irvine, Department of Earth System Science, Irvine, United States

Jennifer Campos Ayala¹, Melinda R. Nicewonger², Armando Byron Vilchez³, Murat Aydin¹, Michael J Prather⁴ and Eric S Saltzman¹, (1)University of California Irvine, Irvine, CA, United States, (2)NOAA Boulder, Boulder, United States, (3)University of California Irvine, Department of Earth System Science, Irvine, United States, (4)Univ California Irvine, Irvine, CA, United States

Paolo Gabrielli¹, John Olesik², Cole Bradley³, Madeleine Claire Lomax-Vogt⁴, Henk Colijn⁵, Aja Ellis⁶, Julia Meyer Sheets², Sue Welch⁷, Ryan C Sullivan⁸, Luke Monroe⁹ and Garret Bland¹⁰, (1)The Ohio State University, Byrd Polar and Climate Research Center, Columbus, OH, United States, (2)The Ohio State University, School of Earth Sciences, Columbus, OH, United States, (3)The Ohio State University, School of Earth Sciences, Columbus, United States, (4)The Ohio State University, Department of Chemistry and Biochemistry, Columbus, OH, United States, (5)The Ohio State University, Center for Electron Microscopy and Analysis, Columbus, United States, (6)The Ohio State University, Byrd Polar and Climate Research Center, Columbus, PA, United States, (7)The Ohio State University, School of Earth Science, Columbus, OH, United States, (8)Carnegie Mellon University, Center for Atmospheric Particle Studies, Pittsburgh, PA, United States, (9)Carnagie Mellon University, Department of Chemistry, Pittsburgh, United States, (10)Carnagie Mellon University, Civil and Environmental Engineering, Pittsburgh, United States

Jenna Epifanio¹, Edward J Brook², Christo Buizert², Jon Shelley Edwards², Todd Sowers³, Emma Carolyn Kahle⁴, Jeffrey P Severinghaus⁵, Tyler R Jones⁶ and Eric J. Steig⁴, (1)Oregon State University, Corvallis, OR, United States, (2)Oregon State University, College of Earth, Ocean, and Atmospheric Sciences, Corvallis, OR, United States, (3)Pennsylvania State University Main Campus, University Park, PA, United States, (4)University of Washington, Earth and Space Sciences, Seattle, WA, United States, (5)Scripps Institution of Oceanography, La Jolla, CA, United States, (6)Institute of Arctic and Alpine Research, Environmental Studies - ENVS, Boulder, CO, United States

Christoph Nehrbass-Ahles¹, Thomas K Bauska², Robert Mulvaney² and Eric W Wolff¹, (1)University of Cambridge, Cambridge, United Kingdom, (2)NERC British Antarctic Survey, Cambridge, United Kingdom

Steven M. Baumann, El Malpais and El Morro National Monuments, Grants, NM, United States, Bogdan P. Onac, University of South Florida Tampa, School of Geosciences, Tampa, FL, United States, Dylan Parmenter, University of Minnesota Twin Cities, Department of Earth & Environmental Sciences, Minneapolis, MN, United States, Eric Weaver, El Malpais and El Morro National Monuments, Grants, United States and Tiberiu B. Sava, Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele, Romania

Emily Doyle¹, Elizabeth Ruth Thomas², Eric W Wolff³ and Alexandra v Turchyn³, (1)University of Cambridge, Department of Earth Sciences, Cambridge, United Kingdom, (2)NERC British Antarctic Survey, Cambridge, United Kingdom, (3)University of Cambridge, Cambridge, United Kingdom

Helene Hoffmann¹, Mackenzie M Grieman¹, Jack Humby², Isobel Rowell¹, Christoph Nehrbass-Ahles¹, Robert Mulvaney³ and Eric W Wolff¹, (1)University of Cambridge, Cambridge, United Kingdom, (2)NERC British Antarctic Survey, Cambridge, United Kingdom, (3)British Antarctic Survey, Cambridge, United Kingdom

Alexander Charles Ihle, Ohio State University Main Campus, Columbus, OH, United States, Paolo Gabrielli, The Ohio State University, Byrd Polar and Climate Research Center, Columbus, OH, United States, Bryan G Mark, OSU-Byrd Polar Rsrch Ctr, Columbus, OH, United States, Michele Brunetti, ISAC CNR, Bologna, Italy, Luca Carturan, University of Padua, Padua, Italy, Giuliano Dreossi, IDPA CNR, Venice, Italy and Barbara Stenni, University of Venice, Venice, Italy