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Evaluation of Global Monitoring and Forecasting Systems at Mercator Océan : Volume 9, Issue 1 (17/01/2013)

By Lellouche, J.-m.

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Book Id: WPLBN0004020664
Format Type: PDF Article :
File Size: Pages 25
Reproduction Date: 2015

Title: Evaluation of Global Monitoring and Forecasting Systems at Mercator Océan : Volume 9, Issue 1 (17/01/2013)  
Author: Lellouche, J.-m.
Volume: Vol. 9, Issue 1
Language: English
Subject: Science, Ocean, Science
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2013
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Drévillon, M., Galloudec, O. L., Régnier, C., Garric, G., Drillet, Y., Ferry, N.,...Benkiran, M. (2013). Evaluation of Global Monitoring and Forecasting Systems at Mercator Océan : Volume 9, Issue 1 (17/01/2013). Retrieved from http://worldlibrary.net/


Description
Description: Mercator Océan, Ramonville Saint Agne, France. Since December 2010, the MyOcean global analysis and forecasting system has consisted of the Mercator Océan NEMO global 1/4° configuration with a 1/12° nested model over the Atlantic and the Mediterranean. The open boundary data for the nested configuration come from the global 1/4° configuration at 20° S and 80° N.

The data are assimilated by means of a reduced-order Kalman filter with a 3-D multivariate modal decomposition of the forecast error. It includes an adaptive-error estimate and a localization algorithm. A 3-D-Var scheme provides a correction for the slowly evolving large-scale biases in temperature and salinity. Altimeter data, satellite sea surface temperature and in situ temperature and salinity vertical profiles are jointly assimilated to estimate the initial conditions for numerical ocean forecasting. In addition to the quality control performed by data producers, the system carries out a proper quality control on temperature and salinity vertical profiles in order to minimise the risk of erroneous observed profiles being assimilated in the model.

This paper describes the recent systems used by Mercator Océan and the validation procedure applied to current MyOcean systems as well as systems under development. The paper shows how refinements or adjustments to the system during the validation procedure affect its quality. Additionally, we show that quality checks (in situ, drifters) and data sources (satellite sea surface temperature) have as great an impact as the system design (model physics and assimilation parameters). The results of the scientific assessment are illustrated with diagnostics over the year 2010 mainly, assorted with time series over the 2007–2011 period. The validation procedure demonstrates the accuracy of MyOcean global products, whose quality is stable over time. All monitoring systems are close to altimetric observations with a forecast RMS difference of 7 cm. The update of the mean dynamic topography corrects local biases in the Indonesian Throughflow and in the western tropical Pacific. This improves also the subsurface currents at the Equator. The global systems give an accurate description of water masses almost everywhere. Between 0 and 500 m, departures from in situ observations rarely exceed 1 °C and 0.2 psu. The assimilation of an improved sea surface temperature product aims to better represent the sea ice concentration and the sea ice edge. The systems under development are still suffering from a drift which can only be detected by means of a 5-yr hindcast, preventing us from upgrading them in real time. This emphasizes the need to pursue research while building future systems for MyOcean2 forecasting.


Summary
Evaluation of global monitoring and forecasting systems at Mercator Océan

Excerpt
Penduff, T., Juza, M., Brodeau, L., Smith, G. C., Barnier, B., Molines, J. M., Treguier, A. M., and Madec, G.: Impact of global ocean model resolution on sea-level variability with emphasis on interannual time scales, Ocean Sci., 6, 269–284, doi:10.5194/os-6-269-2010, 2010.; Pham, D. T., Verron, J., and Roubaud, M. C.: A singular evolutive extended Kalman filter for data assimilation in oceanography, J. Mar. Syst., 16, 323–340, 1998.; Redelsperger, J. L., Thorncroft, C., Diedhiou, A., Lebel, T., Parker, D. J., and Polcher, J.: African Monsoon Multidisciplinary Analysis (AMMA): an international research project and field campaign, B. Am. Meteorol. Soc., 87, 1739–1746, 2006.; Reynolds, R. W. and Chelton, D. B.: Comparisons of Daily Sea Surface Temperature Analyses for 2007–08, J. Climate, 23, 3545–3562, doi:10.1175/2010JCLI3294.1, 2010.; Reynolds, R. W., Smith, T. M., Liu, C., Chelton, D. B., Casey, K. S., and Schlax, M. G.: Daily high-resolution blended analyses for sea surface temperature, J. Climate, 20, 5473–5496, 2007.; Rio, M. H., Guinehut, S., and Larnicol, G.: New CNES-CLS09 global mean dynamic topography computed from the combination of GRACE data, altimetry, and in situ measurements, J. Geophys. Res., 116, C07018, doi:10.1029/2010JC006505, 2011.; Amante C. and Eakins, B. W.: ETOPO1 1 Arc-minute global relief model: procedures, data sources and analysis, NOAA Technical Memorandum NESDIS NGDC-24, 25 pp., 2009.; Antonov, J. I., Locarnini, R. A., Boyer, T. P., Mishonov, A. V., and Garcia, H. E.: World Ocean Atlas 2005, Vol. 2: Salinity, in: NOAA Atlas NESDIS 62, edited by: Levitus, S., US Government Printing Office, Washington, DC, 182 pp., 2006.; Roemmich, D., Belbeoch, M., Belchi, P. J. V., Freeland, H., Gould, W. J., Grant, F., Ignaszewski, M., Klein, B., Mork, K.A., Owens, W.B., Pouliquen, S., Ravichandran, M., Riser, S., Sterl, A., Suga, T., Suk, M. S., Sutton, P., Thierry, V., Le Traon, P. Y., Wijffels, S., and Xu, J.: Argo: the challenge of continuing 10 years of progress, Oceanography, 22, 46–55, 2008.; Roquet, F., Charrassin, J. B., Marchand, S., Boehme, L., Fedak, M., Reverdin, G., and Guinet, C.: Delayed-mode calibration of hydrographic data obtained from animal-borne satellite relay data loggers, J. Atmos. Ocean. Tech., 28, 787–801, 2011.; Roullet, G. and Madec, G.: Salt conservation, free surface, and varying levels: a new formulation for ocean general circulation models, J. Geophys. Res., 105, 23927–23942, 2000.; Silva, T. A. M., Bigg, G. R., and Nicholls, K. W.: Contribution of giant icebergs to the Southern Ocean freshwater flux, J. Geophys. Res., 111, C03004, doi:10.1029/2004JC002843, 2006.; Talagrand, O.: A posteriori evaluation and verification of analysis and assimilation algorithms, Proc. of ECMWF Workshop on Diagnosis of Data Assimilation System (Reading), 17–28, 1998.; Tranchant, B., Testut, C. E., Renault, L., Ferry, N., Birol, F., and Brasseur, P.: Expected impact of the future SMOS and Aquarius Ocean surface salinity missions in the Mercator Océan operational systems: New perspectives to monitor ocean circulation, Remote Sens. Environ., 112, 1476–1487, 2008.; Arakawa, A. and Lamb, V. R.: A potential enstrophy and energy conserving scheme for the shallow water equations, Mon. Weather. Rev., 109, 18–36, 1981.; Barnier, B., Madec, G., Penduff, T., Molines, J. M., Treguier, A. M., Le Sommer, J., Beckmann, A., Biastoch, A., Böning, C., Dengg, J., Derval, C., Durand, E., Gulev, S., Remy, E., Talandier, C., Theetten, S., Maltrud, M., McClean, J., and De Cuevas, B.: Impact of partial steps and momentum advection schemes in a global circulation model at eddy permitting resolution, Ocean Dynam., 56, 543–567, 2006.; Becker, J. J., Sandwell, D. T., Smith, W.

 

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