Climate sensitivity of the century-scale hydrogen peroxide (H2O2) record preserved in 23 ice cores from West Antarctica
[1] We report new century-scale ice core records of hydrogen peroxide (H2O2), a major atmospheric oxidant, from 23 locations across the West Antarctic Ice Sheet (WAIS) and use the spatial variability of (multi-) annual mean H2O2 concentrations in snow and firn to investigate the sensitivity of ice c...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
| Published: |
2006
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.517.6319 http://zero.eng.ucmerced.edu/rcbales/Itase/pdf_docs/Frey_2006JGR.pdf |
| Summary: | [1] We report new century-scale ice core records of hydrogen peroxide (H2O2), a major atmospheric oxidant, from 23 locations across the West Antarctic Ice Sheet (WAIS) and use the spatial variability of (multi-) annual mean H2O2 concentrations in snow and firn to investigate the sensitivity of ice core H2O2 preservation to mean annual temperature and accumulation rate. In agreement with the ice-air equilibrium partitioning, H2O2 uptake in near-surface firn was found to be greatest at low temperatures, while postdepositional losses from degassing increase as accumulation rates decrease. This resulted in almost complete loss of H2O2 at warm (>25C), low-accumulation sites (<13 cm yr1), but excellent preservation of records at cold, high-accumulation sites. A two-parameter semiempirical model fitted to the 1911–1960 H2O2 means across all sites predicts>94 % deviations from the ice-air equilibrium at high-accumulation sites (>30 cm yr1), but close-to-equilibrium values on the East Antarctic Plateau, where it is dry (<11 cm yr1). It also estimates a weighted average of the annual atmospheric H2O2 cycle of 1–3 pptv, about 10 % of the levels at the bottom of the H2O2 range observed in winter and early spring in coastal Antarctica. Sensitivities from the model fit |
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