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A. Bellucci, S. Masina, P. DiPietro, and A. Navarra

observations (mainly hydrography and altimetry data) in the assimilation process ( Segschneider et al. 2001 ; Masina et al. 2001 ; Carton et al. 2000 ). An aspect that has been somewhat overlooked in the ocean reanalyses production is the role of salinity. The scarcity of direct salinity observations and the belief that this tracer has a second-order impact on the tropical ocean density structure compared to temperature, were reasons why salinity has often been left unchanged during the temperature

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Olwijn Leeuwenburgh

observed one) and that additionally conserve dynamical balances. A common application has been the estimation of subsurface corrections from sea level observations based on mode decomposition ( Fukumori et al. 1999 ), raising or lowering the temperature–salinity ( T – S ) profile ( Cooper and Haines 1996 ), regression between sea level and EOFs of observed subsurface variability ( Fischer et al. 1997 ), or on multivariate covariances estimated from model runs ( Borovikov et al. 2005 ). Model error

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K. Haines, J. D. Blower, J-P. Drecourt, C. Liu, A. Vidard, I. Astin, and X. Zhou

1. Introduction As more salinity observations become available from Argo floats ( Roemmich et al. 2001 ), it is becoming more important to develop methods to assimilate salinity profile data into ocean circulation models. Representing the salinity field correctly in ocean models is important in a number of contexts. Salinity has an impact on the density field and hence on ocean currents and transports (e.g., Cooper 1988 ; Roemmich et al. 1994 ; Vialard and Delecluse 1998a , b ). Salinity is

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Alberto Troccoli, Magdalena Alonso Balmaseda, Joachim Segschneider, Jerome Vialard, David L. T. Anderson, Keith Haines, Tim Stockdale, Frederic Vitart, and Alan D. Fox

assimilated. Not much attention has been given to salinity in the context of temperature data assimilation for seasonal climate forecasts. Hitherto, the most common approach has been to leave the salinity field unmodified when updating the temperature field. This is partly because subsurface salinity observations available in near–real time are very sparse, and partly because the salinity field was thought to be of less importance for the density in the upper tropical ocean. However we will show that not

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S. Daniel Jacob and Chester J. Koblinsky

of oceanic circulation include the Loop Current and the warm mesoscale eddies that separate from it. The water mass associated with these features has a distinct temperature–salinity ( T – S ) relationship in contrast to the Gulf Common Water (GCW). Earlier studies have documented the importance of realistic initialization of the ocean model for more accurate ocean response simulation due to hurricane passage ( JSMB ; Jacob and Shay 2003 ). However, as the main focus of the present study is to

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S. Ricci, A. T. Weaver, J. Vialard, and P. Rogel

1. Introduction In the Tropics, salinity effects have often been neglected when studying the ocean general circulation. Looking at averaged conditions this assumption is justified: the change in density due to changes in temperature is much greater than the change in density due to changes in salinity. Nevertheless, several studies have shown that salinity can play an important role in the variability of the tropical oceans. For example, Roemmich et al. (1994) have shown that salinity

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Yimin Liu and Keith R. Thompson

1. Introduction Observations of sea surface height by altimeters, and the vertical structure of temperature and salinity by Argo floats, are leading to new insights into the variability and physics of the world’s oceans. Even though the global coverage of these observations is unprecedented, their use in mapping the ocean, and initializing forecast models, remains problematic because altimeters provide no direct information on vertical structure of the ocean and the horizontal spacing of Argo

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Mei Zhao, Harry H. Hendon, Oscar Alves, Yonghong Yin, and David Anderson

follows from improvements in the ocean assimilation systems (e.g., Ji and Leetmaa 1997 ; Rosati et al. 1997 ; Wang et al. 2002 ; Balmaseda et al. 2008 ; Stockdale et al. 2011 ). In addition, recent studies have shown that accurately representing the salinity stratification is also important, for instance at the onset of El Niño ( Maes and Picaut 2002 ; Maes et al. 2005 ), and that surface salinity has the potential to impact ENSO prediction ( Ballabrera-Poy et al. 2002 ; Hackert et al. 2011

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A. Vidard, D. L. T. Anderson, and M. Balmaseda

region ( McPhaden 1995 ; Servain et al. 1998 ) and the global Volunteer Observing Ship (VOS) program, which provides expendable bathythermograph (XBT) measurements mainly along merchant shipping routes. More recently, observations are provided by the Argo network of drifting profilers. The latter frequently provide salinity measurements, also but these are not assimilated in the experiments described here and can be used as independent data for diagnostic purposes. Because funding is always limited

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paper.The records to which Mr. Marvin referred were kept in theform of a diary by his great-grandfather, Mr. Thomas Pope.I n order to understand why Mr. Pope kept such a carefuldiary, some salient points of his life need to be noted. Hewas born at New Bedford, Mass., and spent his early life inthe New England States. He was graduated from Harvardin 1833, and nodoubt acquired a soientific turn of mind whilein college. I n 1838 he moved to Saline, Mich., near whichplace he bought a farm, and began

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