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Titel |
Sea level budget over 2005–2013: missing contributions and data errors |
VerfasserIn |
H. B. Dieng, A. Cazenave, K. von Schuckmann, M. Ablain, B. Meyssignac |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1812-0784
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Digitales Dokument |
URL |
Erschienen |
In: Ocean Science ; 11, no. 5 ; Nr. 11, no. 5 (2015-10-06), S.789-802 |
Datensatznummer |
250117294
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Publikation (Nr.) |
copernicus.org/os-11-789-2015.pdf |
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Zusammenfassung |
Based on the sea level budget closure approach, this study investigates the
residuals between observed global mean sea level (GMSL) and the sum of
components (steric sea level and ocean mass) for the period January 2005 to
December 2013. The objective is to identify the impact of errors in one or
several components of the sea level budget on the residual time series. This
is a key issue if we want to constrain missing contributions such as the
contribution to sea level rise from the deep ocean (depths not covered by
observations). For that purpose, we use several data sets as processed by
different groups: six altimetry products for the GMSL, four Argo products
plus the ORAS4 ocean reanalysis for the steric sea level and three
GRACE-based ocean mass products. We find that over the study time span, the
observed differences in trend of the residuals of the sea level budget
equation can be as large as ~ 0.55 mm yr−1 (i.e.,
~ 17 % of the observed GMSL rate of rise). These trend differences
essentially result from differences in trends of the GMSL time series. Using
the ORAS4 reanalysis (providing complete geographical coverage of the steric
sea level component), we also show that lack of Argo data in the Indonesian
region leads to an overestimate of the absolute value of the residual trend
by about 0.25 mm yr−1. Accounting for this regional contribution leads
to closure of the sea level budget, at least for some GMSL products. At short
timescales (from sub-seasonal to interannual), residual anomalies are
significantly correlated with ocean mass and steric sea level anomalies
(depending on the time span), suggesting that the residual anomalies are
related to errors in both GRACE-based ocean mass and Argo-based steric data.
Efforts are needed to reduce these various sources of errors before using the
sea level budget approach to estimate missing contributions such as the deep
ocean heat content. |
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