A comprehensive assessment of ions in snow and ice cores based on global observational data

Snow and ice are important reservoirs of atmospheric ions, yet a comprehensive understanding of ions in snow/ice remains a challenge due to spatiotemporal limitations of field campaigns. To address this issue, mathematical statistics were employed to summarize global observational data from 49 published sources covering 546 snow and 19 ice core sampling sites. The findings show remarkable variability in ion concentrations and compositions in snow, with differences spanning 4 to 6 orders of magnitude. This variation changes with elevation, season and historical development, and differs regionally and within regions. These complex patterns of ion distribution in snow and ice are shaped by a range of factors, including local and remote emission sources, trans-regional transports, atmospheric circulations, natural climate variability, geographical features and environmental factors. This comprehensive global analysis would effectively enhance our understanding of snow and ice chemistry and its significant environmental implications, particularly in the context of a rapid changing global climate.