Environmental signals from chemical measurements on Law Dome ice cores ...

• Main Author: Palmer, Anne Susan
• Format: Thesis
• Language: unknown
• Published: University Of Tasmania 2023
• Subjects: East Antarctica; Law Dome; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.25959/23245784; https://figshare.utas.edu.au/articles/thesis/Environmental_signals_from_chemical_measurements_on_Law_Dome_ice_cores/23245784

This study presents a 695-year record of the trace ion chemistry preserved in ice cores from the summit of Law Dome, East Antarctica. The record has seasonal resolution. The record was dated by counting the annual cycles in the oxygen isotope ratio. Ambiguous years were resolved by examination of the seasonality of the time-series of hydrogen peroxide, sodium, and non-sea-salt sulphate, as well as by comparison with other ice cores from the Law Dome region. This allowed unambiguous dating during the most recent period 1807-1995, with a maximum uncertainty of plus or minus 1 year at the beginning of the record in 1301. The time-series of sodium provides an excellent record of past storm activity in the Law Dome region. Extreme storm events appear as positive deviations from the mean annual cycle, which reaches maximum values in the winter months. The time-series also shows evidence for the chemical fractionation of sea-salt aerosol, with an average 60% depletion of sodium sulphate relative to sodium chloride. ...