OS Ocean Science OS Ocean Sci. 1812-0792 Copernicus Publications Göttingen, Germany 10.5194/os-5-475-2009 Enhancing temporal correlations in EOF expansions for the reconstruction of missing data using DINEOF Alvera-Azcárate A. 1 2 Barth A. 1 2 Sirjacobs D. 3 Beckers J.-M. 1 AGO-GHER, University of Liège, Allée du Six Août, 17, Sart Tilman, Liège, 4000, Belgium National Fund for Scientific Research, FNRS-FRS, Belgium Department of Life Sciences, University of Liège, Sart Tilman, Liège, 4000, Belgium 28 10 2009 5 4 475 485 Copyright: © 2009 A. Alvera-Azcárate et al. 2009 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://os.copernicus.org/articles/5/475/2009/os-5-475-2009.html The full text article is available as a PDF file from https://os.copernicus.org/articles/5/475/2009/os-5-475-2009.pdf

DINEOF (Data Interpolating Empirical Orthogonal Functions) is an EOF-based technique for the reconstruction of missing data in geophysical fields, such as those produced by clouds in sea surface temperature satellite images. A technique to reduce spurious time variability in DINEOF reconstructions is presented. The reconstruction of these images within a long time series using DINEOF can lead to large discontinuities in the reconstruction. Filtering the temporal covariance matrix allows to reduce this spurious variability and therefore more realistic reconstructions are obtained. The approach is tested in a three years sea surface temperature data set over the Black Sea. The effect of the filter in the temporal EOFs is presented, as well as some examples of the improvement achieved with the filtering in the SST reconstruction, both compared to the DINEOF approach without filtering.

 References Alvera-Azcárate, A., Barth, A., Rixen, M., and Beckers, J.&nbsp;M.: Reconstruction of incomplete oceanographic data sets using {E}mpirical {O}rthogonal {F}unctions. {A}pplication to the {A}driatic {S}ea surface temperature, Ocean Modelling., 9, 325–346, 2005. Alvera-Azcárate, A., Barth, A., Beckers, J.&nbsp;M., and Weisberg, R.&nbsp;H.: Multivariate Reconstruction of Missing Data in Sea Surface Temperature, Chlorophyll and Wind Satellite Fields, J. Geophys. Res., 112, C03008, https://doi.org/10.1029/2006JC003660, 2007. Beckers, J.-M. and Rixen, M.: EOF calculations and data filling from incomplete oceanographic data sets, Journal of Atmospheric and Oceanic Technology, 20, 1839–1856, 2003. Beckers, J.-M., Barth, A., and Alvera-Azcárate, A.: DINEOF reconstruction of clouded images including error maps. {A}pplication to the Sea Surface Temperature around Corsican Island, Ocean Sci., 2, 183–199, 2006. Castro, S.&nbsp;L., Wick, G.&nbsp;A., Jackson, D.&nbsp;L., and Emery, W.&nbsp;J.: Error characterization of infrared and microwave satellite sea surface temperature products for merging and analysis, J. Geophys. Res., 113, C03010, https://doi.org/10.1029/2006JC003829, 2008. Gawarkiewicz, G., Korotaev, G., Stanichny, S., Repetin, L., and Soloviev, D.: Synoptic upwelling and cross-shelf transport processes along the Crimean coast of the Black Sea, Cont. Shelf Res., 19, 977–1005, 1999. Gentemann, C.&nbsp;L., Wentz, F.&nbsp;J., Mears, C.&nbsp;A., and Smith, D.&nbsp;K.: In situ validation of Tropical Rainfall Measuring Mission microwave sea surface temperatures, J. Geophys. Res., 109, C04021, https://doi.org/10.1029/2003JC002092, 2004. Kosarev, A.&nbsp;N., Kostianoy, A.&nbsp;G., and Shiganova, T.&nbsp;A.: The Black Sea Environment, vol.&nbsp;5Q of \em The Handbook of Environmental Chemistry\/, chap.&nbsp;The Sea of Azov, 63–89, Springer, 2008. Kumar, A., Minnet, P., Podesta, G., Evans, R., and Kilpatrick, K.: Analysis of Pathfinder SST algorithm for global and regional conditions, Proceedings of the Indian Academy of Sciences (Earth and Planetary Sciences), 109, 395–405, 2000. Lehoucq, R.&nbsp;B., Sorensen, D.&nbsp;C., and Yang, C.: ARPACK user's guide: solution of large scale eigenvalue problems with implicity restarted {A}rnoldi methods, 1–152, \urlprefix<a href="http://www.caam.rice.edu/software/ARPACK/">http://www.caam.rice.edu/software/ARPACK/</a>, 1997. Marullo, S., Buongiorno&nbsp;Nardelli, B., Guarracino, M., and Santoleri, R.: Observing the Mediterranean Sea from space: 21 years of Pathfinder-AVHRR sea surface temperatures (1985 to 2005): re-analysis and validation, Ocean Sci., 3, 299–310, 2007. McClain, E., Pichel, W., and Walton, C.: Comparative performance of {AVHRR}-based multichannel sea surface temperatures, J. Geophys. Res., 90(C6), 11587–11601, 1985. Sur, H.&nbsp;L. and Ilyin, Y.&nbsp;P.: Evolution of satellite derived mesoscale thermal patterns in the Black Sea, Prog. Oceanogr., 39, 109–151, 1997. Sur, H.&nbsp;L., Özsoy, E., Ilyin, Y.&nbsp;P., and Ünlüata, U.: Coastal/deep ocean interactions in the Black Sea and their ecological/environmental impacts, J. Marine Syst., 7, 293–320, 1996. Toumazou, V. and Cretaux, J.&nbsp;F.: Using a {L}anczos eigensolver in the computation of {E}mpirical {O}rthogonal {F}unctions, Mon. Weather Rev., 129, 1243–1250, 2001.