Inferring palaeo-accumulation records from ice-core data by an adjoint-based method: application to James Ross Island's ice core

Martín, Carlos ORCID: https://orcid.org/0000-0002-2661-169X; Mulvaney, Robert ORCID: https://orcid.org/0000-0002-5372-8148; Gudmundsson, G. Hilmar ORCID: https://orcid.org/0000-0003-4236-5369; Corr, Hugh. 2015 Inferring palaeo-accumulation records from ice-core data by an adjoint-based method: application to James Ross Island's ice core. Climate of the Past, 11. 547-557. 10.5194/cp-11-547-2015

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Abstract/Summary

Ice cores contain a record of snow precipitation that includes information about past atmospheric circulation and mass imbalance in the polar regions. We present a novel adjoint method to reconstruct a climatic record by both optimally dating an ice-core and deriving 5 from it a detailed accumulation history. The motivation of our work is the recent application of phase sensitive radar which measures the vertical velocity of an ice column. The velocity is dependent on the history of subsequent snow accumulation, compaction and compression; and in our inverse formulation of this problem, measured vertical velocity profiles can be utilized directly thereby reducing the uncertainty intro10 duced by ice flow modelling. We first apply our method to synthetic data in order to study its capability and the effect of noise and gaps in the data on retrieved accumulation history. The method is then applied to the ice core retrieved from James Ross Island, Antarctica. We show that the method is robust and that the results depend on quality of the age-depth observations and the derived flow regime around the core site. 15 The method facilitates the incorporation of increasing detail provided by ice-core analysis together with observed full-depth velocity in order to construct a complete climatic record of the polar regions.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.5194/cp-11-547-2015
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Chemistry and Past Climate BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ice Sheets
Date made live:	29 Sep 2014 09:38 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/507869

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.5194/cp-11-547-2015

Programmes:

BAS Programmes > Polar Science for Planet Earth (2009 - ) > Chemistry and Past Climate
BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ice Sheets

Date made live:

29 Sep 2014 09:38 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/507869