Change search
ReferencesLink to record
Permanent link

Direct link
Reanalyzing temperature and salinity on decadal time scales using the ensemble optimal interpolation data assimilation method and a 3D ocean circulation model of the Baltic Sea
Stockholm University, Faculty of Science, Department of Meteorology .
2013 (English)In: Journal Of Geophysical Research: Oceans, ISSN 2169-9275, Vol. 118, no 10, 5536-5554 p.Article in journal (Refereed) Published
Abstract [en]

A 30-year (1970-1999) reanalysis of temperature and salinity is conducted by assimilating temperature and salinity profiles into an ocean model of the Baltic Sea with ensemble optimal interpolation approach. Some configurations of the reanalysis are presented. For example, the samples are chosen from the same season as the analysis time to address the strong seasonal variability. The impact of different observation time windows on the analysis results is also discussed. A locally determined alpha is adopted for the long-time-scale simulation. To assess the accuracy of the reanalysis, a set of comparisons between the reanalysis results and the free run results was performed. The root mean square deviations (RMSDs) between the reanalysis results and not-yet-assimilated observations at all levels show that, compared to the free run, temperature and salinity have been improved significantly, that is, by 31.1 and 38.8%, respectively. The vertical structure of the reanalyzed fields is also adjusted. The reanalysis results show that the improvements in both temperature and salinity are smaller at greater water depths. Comparison with independent CTD data, the reanalysis significantly improved temperatures and salinities in all layers relative to the free run. For temperature and salinity during the period of ship voyages, the RMSDs are reduced by 32.9 and 25.5%, respectively. The temporal variations of the deep-water salinity caused by saltwater inflows are better captured by the reanalysis than by the free run. Moreover, the reanalysis improved the estimation of the depth of the halocline and thermocline, which are overestimated in the simulation without data assimilation.

Place, publisher, year, edition, pages
2013. Vol. 118, no 10, 5536-5554 p.
National Category
Oceanography, Hydrology, Water Resources
URN: urn:nbn:se:su:diva-98096DOI: 10.1002/jgrc.20384ISI: 000327380100049OAI: diva2:682310


Funding agencies:

European Community 217246; joint Baltic Sea research and development programme; Swedish Environmental Protection Agency (SEPA) 08/381; Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS) 214-2009-577, 214-2010-1575; Stockholm University's Strategic Marine Environmental Research Funds "Baltic Ecosystem Adaptive Management (BEAM)"; Knut and Alice Wallenberg foundation 

Available from: 2013-12-27 Created: 2013-12-27 Last updated: 2013-12-27Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Meier, H. E. Markus
By organisation
Department of Meteorology
Oceanography, Hydrology, Water Resources

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 227 hits
ReferencesLink to record
Permanent link

Direct link