Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation
Previous GRACE-derived ice mass trends and accelerations have almost entirely been based on an assumption that the residuals to a regression model (including also semi-annual, annual and tidal aliasing terms) are not serially correlated. We consider ice mass change time series for Antarctica and sho...
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ftnerc:oai:nora.nerc.ac.uk:503921 2023-05-15T13:48:08+02:00 Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation Williams, Simon D.P. Moore, Philip King, Matt A. Whitehouse, Pippa L. 2014-01 text http://nora.nerc.ac.uk/id/eprint/503921/ https://nora.nerc.ac.uk/id/eprint/503921/1/1-s2.0-S0012821X13005797-main.pdf https://doi.org/10.1016/j.epsl.2013.10.016 en eng https://nora.nerc.ac.uk/id/eprint/503921/1/1-s2.0-S0012821X13005797-main.pdf Williams, Simon D.P. orcid:0000-0003-4123-4973 Moore, Philip; King, Matt A.; Whitehouse, Pippa L. 2014 Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation. Earth and Planetary Science Letters, 385. 12-21. https://doi.org/10.1016/j.epsl.2013.10.016 <https://doi.org/10.1016/j.epsl.2013.10.016> Publication - Article PeerReviewed 2014 ftnerc https://doi.org/10.1016/j.epsl.2013.10.016 2023-02-04T19:38:06Z Previous GRACE-derived ice mass trends and accelerations have almost entirely been based on an assumption that the residuals to a regression model (including also semi-annual, annual and tidal aliasing terms) are not serially correlated. We consider ice mass change time series for Antarctica and show that significant autocorrelation is, in fact, present. We examine power-law and autoregressive models and compare them to those that assume white (uncorrelated) noise. The data do not let us separate autoregressive and power-law models but both indicate that white noise uncertainties need to be scaled up by a factor of up to 4 for accelerations and 6 for linear rates, depending on length of observations and location. For the whole of Antarctica, East Antarctica and West Antarctica the scale factors are 1.5, 1.5 and 2.2 respectively for the trends and, for the accelerations, 1.5, 1.5 and 2.1. Substantially lower scale-factors are required for offshore time series, suggesting much of the time-correlation is related to continental mass changes. Despite the higher uncertainties, we find significant (2-sigma) accelerations over much of West Antarctica (overall increasing mass loss) and Dronning Maud Land (increasing mass gain) as well as a marginally significant acceleration for the ice sheet as a whole (increasing mass loss). Article in Journal/Newspaper Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet West Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic East Antarctica Dronning Maud Land West Antarctica Earth and Planetary Science Letters 385 12 21 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Previous GRACE-derived ice mass trends and accelerations have almost entirely been based on an assumption that the residuals to a regression model (including also semi-annual, annual and tidal aliasing terms) are not serially correlated. We consider ice mass change time series for Antarctica and show that significant autocorrelation is, in fact, present. We examine power-law and autoregressive models and compare them to those that assume white (uncorrelated) noise. The data do not let us separate autoregressive and power-law models but both indicate that white noise uncertainties need to be scaled up by a factor of up to 4 for accelerations and 6 for linear rates, depending on length of observations and location. For the whole of Antarctica, East Antarctica and West Antarctica the scale factors are 1.5, 1.5 and 2.2 respectively for the trends and, for the accelerations, 1.5, 1.5 and 2.1. Substantially lower scale-factors are required for offshore time series, suggesting much of the time-correlation is related to continental mass changes. Despite the higher uncertainties, we find significant (2-sigma) accelerations over much of West Antarctica (overall increasing mass loss) and Dronning Maud Land (increasing mass gain) as well as a marginally significant acceleration for the ice sheet as a whole (increasing mass loss). |
format |
Article in Journal/Newspaper |
author |
Williams, Simon D.P. Moore, Philip King, Matt A. Whitehouse, Pippa L. |
spellingShingle |
Williams, Simon D.P. Moore, Philip King, Matt A. Whitehouse, Pippa L. Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation |
author_facet |
Williams, Simon D.P. Moore, Philip King, Matt A. Whitehouse, Pippa L. |
author_sort |
Williams, Simon D.P. |
title |
Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation |
title_short |
Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation |
title_full |
Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation |
title_fullStr |
Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation |
title_full_unstemmed |
Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation |
title_sort |
revisiting grace antarctic ice mass trends and accelerations considering autocorrelation |
publishDate |
2014 |
url |
http://nora.nerc.ac.uk/id/eprint/503921/ https://nora.nerc.ac.uk/id/eprint/503921/1/1-s2.0-S0012821X13005797-main.pdf https://doi.org/10.1016/j.epsl.2013.10.016 |
geographic |
Antarctic East Antarctica Dronning Maud Land West Antarctica |
geographic_facet |
Antarctic East Antarctica Dronning Maud Land West Antarctica |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land East Antarctica Ice Sheet West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/503921/1/1-s2.0-S0012821X13005797-main.pdf Williams, Simon D.P. orcid:0000-0003-4123-4973 Moore, Philip; King, Matt A.; Whitehouse, Pippa L. 2014 Revisiting GRACE Antarctic ice mass trends and accelerations considering autocorrelation. Earth and Planetary Science Letters, 385. 12-21. https://doi.org/10.1016/j.epsl.2013.10.016 <https://doi.org/10.1016/j.epsl.2013.10.016> |
op_doi |
https://doi.org/10.1016/j.epsl.2013.10.016 |
container_title |
Earth and Planetary Science Letters |
container_volume |
385 |
container_start_page |
12 |
op_container_end_page |
21 |
_version_ |
1766248710459621376 |