@Article{acp-2020-95, AUTHOR = {Birner, B. and Chipperfield, M. P. and Morgan, E. J. and Stephens, B. B. and Linz, M. and Feng, W. and Wilson, C. and Bent, J. D. and Wofsy, S. C. and Severinghaus, J. and Keeling, R. F.}, TITLE = {Gravitational separation of Ar/N$_2$ and age of air in the lowermost stratosphere in airborne observations and a chemical transport model}, JOURNAL = {Atmospheric Chemistry and Physics Discussions}, VOLUME = {2020}, YEAR = {2020}, PAGES = {1--34}, URL = {https://acp.copernicus.org/preprints/acp-2020-95/}, DOI = {10.5194/acp-2020-95} }