A preliminary record of changes in Southern Hemisphere atmospheric OH abundance from 14CO in glacial ice (Law Dome, Antarctica, 1870 AD to present)

Simple item page
dc.contributor.authorNeff, PDen_AU
dc.contributor.authorPetrenko, VVen_AU
dc.contributor.authorEtheridge, DMen_AU
dc.contributor.authorSmith, AMen_AU
dc.contributor.authorCrosier, EMen_AU
dc.contributor.authorHmiel, Ben_AU
dc.contributor.authorThornton, DPen_AU
dc.contributor.authorJong, LMen_AU
dc.contributor.authorBeaudette, Ren_AU
dc.contributor.authorHarth, CMen_AU
dc.contributor.authorLangenfelds, RLen_AU
dc.contributor.authorMitrevski, Ben_AU
dc.contributor.authorCurran, MAJen_AU
dc.contributor.authorBuizert, Cen_AU
dc.contributor.authorMurray, LTen_AU
dc.contributor.authorTrudinger, CMen_AU
dc.contributor.authorDyonisius, MNen_AU
dc.contributor.authorNg, Jen_AU
dc.contributor.authorSeveringhaus, JPen_AU
dc.contributor.authorWeiss, RFen_AU
dc.date.accessioned2023-02-17T03:35:20Zen_AU
dc.date.available2023-02-17T03:35:20Zen_AU
dc.date.issued2021-12-17en_AU
dc.date.statistics2023-01-27en_AU
dc.description.abstractHydroxyl, OH, is the main tropospheric oxidant and determines the lifetime of methane and most other trace gases in the atmosphere, thereby controlling the amount of greenhouse warming produced by these gases. Changes in OH concentration ([OH]) in response to large changes in reactive trace gas emissions (which may occur in the future) are uncertain. Measurements of 14C-containing carbon monoxide (14CO) and other tracers such as methyl chloroform over the last ≈25 years have been successfully used to monitor changes in average [OH], but there are no observational constraints on [OH] further back in time. Reconstructions of 14CO from ice cores at sites with very high snow accumulation rates can provide such constraints, as rapid snow burial limits in-situ production of 14CO by cosmic rays directly in the ice. A joint US and Australian team sampled and measured firn air and ice at Law Dome, Antarctica (2018-19 season, site DE08-OH, 1.2 m a-1 ice-equivalent snow accumulation), to a maximum depth of 240 m. Trapped air was extracted from the ice using an on-site large-volume ice melting system. Preliminary comparisons of methane measured in the samples to existing ice core records and atmospheric measurements suggest ice core air sample ages spanning from the 1870s to the early 2000s. Firn-air samples from the snow surface to 81 m depth capture air from the early 2000s to present. Analyses of [CO] and halocarbons in the samples show a relatively low and stable procedural CO blank and demonstrate that the samples are unaffected by ambient air inclusion. 14CO analyses in these firn and ice core air samples have been successfully completed. Corrections for in-situ 14CO production, validated against direct atmospheric measurements for the more recent samples, have allowed us to develop a preliminary 14CO history. This history will be interpreted with the aid of the GEOS-Chem chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere [OH] since ≈1870 AD.en_AU
dc.identifier.articlenumberC41B-02en_AU
dc.identifier.booktitleAGU Fall Meeting Abstractsen_AU
dc.identifier.citationNeff, P. D., Petrenko, V. V., Etheridge, D. M., Smith, A., M., Crosier, E., Hmiel, B., Thornton, D., Jong, L. M., Beaudette, R., Harth, C. M., Langenfelds, R. L., Mitrevski, B., Curran, M., Buizert, C., Murray, L. T., Trudinger, C. M., Dyonisius, M., Ng, J., Severinghaus, J. P., & Weiss, R. F. (2021). A preliminary record of changes in Southern Hemisphere atmospheric OH abundance from 14CO in glacial ice (Law Dome, Antarctica, 1870 AD to present). Paper presented at the AGU Fall Meeting 2021, New Orleans, Louisiana and Online, 13-17 December 2021. In AGU Fall Meeting Abstracts (Vol. 2021, C41B-02). Retrieved from: https://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/974350en_AU
dc.identifier.conferenceenddate17 December 2021en_AU
dc.identifier.conferencenameAGU Fall Meeting 2021en_AU
dc.identifier.conferenceplaceNew Orleans, Louisiana and Onlineen_AU
dc.identifier.conferencestartdate13 December 2021en_AU
dc.identifier.urihttps://agu.confex.com/agu/fm21/meetingapp.cgi/Paper/974350en_AU
dc.identifier.urihttps://apo.ansto.gov.au/dspace/handle/10238/14655en_AU
dc.identifier.volume2021en_AU
dc.language.isoenen_AU
dc.publisherAmerican Geophysical Union (AGU)en_AU
dc.subjectRecords managementen_AU
dc.subjectSouthern Hemisphereen_AU
dc.subjectCarbon 14en_AU
dc.subjectAntarcticaen_AU
dc.subjectMethaneen_AU
dc.subjectCarbon monoxideen_AU
dc.subjectIceen_AU
dc.subjectDrill coresen_AU
dc.subjectSnowen_AU
dc.subjectMeltingen_AU
dc.subjectAtmospheric chemistryen_AU
dc.titleA preliminary record of changes in Southern Hemisphere atmospheric OH abundance from 14CO in glacial ice (Law Dome, Antarctica, 1870 AD to present)en_AU
dc.typeConference Presentationen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.63 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Conference Publications