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| Titel |
Impact of SLA assimilation in the Sicily Channel Regional Model: model skills and mesoscale features |
| VerfasserIn |
A. Olita, S. Dobricic, A. Ribotti, L. Fazioli, A. Cucco, C. Dufau, R. Sorgente |
| 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 ; 8, no. 4 ; Nr. 8, no. 4 (2012-07-17), S.485-496 |
| Datensatznummer |
250005746
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| Publikation (Nr.) |
 copernicus.org/os-8-485-2012.pdf |
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| Zusammenfassung |
| The impact of the assimilation of MyOcean sea level anomalies along-track
data on the analyses of the Sicily Channel Regional Model was studied. The
numerical model has a resolution of 1/32° degrees and is capable to
reproduce mesoscale and sub-mesoscale features. The impact of the SLA
assimilation is studied by comparing a simulation (SIM, which does not
assimilate data) with an analysis (AN) assimilating SLA along-track
multi-mission data produced in the framework of MyOcean project. The quality
of the analysis was evaluated by computing RMSE of the misfits between
analysis background and observations (sea level) before assimilation. A
qualitative evaluation of the ability of the analyses to reproduce mesoscale
structures is accomplished by comparing model results with ocean colour and
SST satellite data, able to detect such features on the ocean surface. CTD
profiles allowed to evaluate the impact of the SLA assimilation along the
water column. We found a significant improvement for AN solution in terms of
SLA RMSE with respect to SIM (the averaged RMSE of AN SLA misfits over 2 years
is about 0.5 cm smaller than SIM). Comparison with CTD data shows a
questionable improvement produced by the assimilation process in terms of
vertical features: AN is better in temperature while for salinity it gets
worse than SIM at the surface. This suggests that a better a-priori
description of the vertical error covariances would be desirable. The
qualitative comparison of simulation and analyses with synoptic satellite independent data proves
that SLA assimilation allows to correctly
reproduce some dynamical features (above all the circulation in the Ionian
portion of the domain) and mesoscale structures otherwise misplaced or
neglected by SIM. Such mesoscale changes also infer that the eddy momentum
fluxes (i.e. Reynolds stresses) show major changes in the Ionian area.
Changes in Reynolds stresses reflect a different pumping of eastward momentum
from the eddy to the mean flow, in turn influencing transports through the
channel. |
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