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Titel |
An assessment of particle filtering methods and nudging for climate state reconstructions |
VerfasserIn |
S. Dubinkina, H. Goosse |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1814-9324
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Digitales Dokument |
URL |
Erschienen |
In: Climate of the Past ; 9, no. 3 ; Nr. 9, no. 3 (2013-05-17), S.1141-1152 |
Datensatznummer |
250018057
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Publikation (Nr.) |
copernicus.org/cp-9-1141-2013.pdf |
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Zusammenfassung |
Using the climate model of intermediate complexity LOVECLIM in an idealised
framework, we assess three data-assimilation methods for reconstructing the
climate state. The methods are a nudging, a particle filter with sequential
importance resampling, and a nudging proposal particle filter and the test
case corresponds to the climate of the high latitudes of the Southern
Hemisphere during the past 150 yr. The data-assimilation methods constrain
the model by pseudo-observations of surface air temperature anomalies
obtained from the same model, but different initial conditions. All three
data-assimilation methods provide with good estimations of surface air
temperature and of sea ice concentration, with the nudging proposal particle
filter obtaining the highest correlations with the pseudo-observations. When
reconstructing variables that are not directly linked to the
pseudo-observations such as atmospheric circulation and sea surface salinity,
the particle filters have equivalent performance and their correlations are
smaller than for surface air temperature reconstructions but still
satisfactory for many applications. The nudging, on the contrary, obtains sea
surface salinity patterns that are opposite to the pseudo-observations, which
is due to a spurious impact of the nudging on vertical exchanges in the
ocean. |
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