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K. R. Thompson, R. F. Marsden, and D. G. Wright

stress is given in terms of the mean and variance of thewind fluctuations over the averaging period. The formula is nonlinear with respect to the mean wind speed. The formula is tested using 3 h wind observations from eight North Atlantic Ocean Weather Ships. Mean wind stress is calculated 1) by vector averaging the 3 h wind stresses, and 2) by applying the approximate formula. For an averaging period of 4 months the two methods agree to within _+0.025 Pa, 95% of the time. For an averaging period of

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Arne Biastoch and Wolfgang Krauss

; shortwave radiation is included as a direct penetrative insolation. Together with the wind values all data are taken from a consistent monthly climatology ( Barnier et al. 1995 ), an analysis of the weather forecast model of the European Centre for Medium-Range Weather Forecasts (ECMWF). The cube of the friction velocity ( u * 3 ) is used to force a simple mixed layer model of the Kraus–Turner type [ Kraus and Turner (1967); wind-driven part only). The surface salinity is restored with a timescale of

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Norman T. Camp and Russell L. Elsberry

isstudied using ocean weather ship observations supplemented by simulations with a bulk turbulent kineticenergy model. A total of 49 cases with durations of 10-30 days and including one or more impulsive increases in wind speed were selected from three ocean weather ship records. A characteristic response ofrapid deepening and cooling of the ocean mixed layer is found as extratropical cyclones pass. Periodsbetween storms tend to exhibit little deepening, or even layer retreat, if the net heat flux at

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James E. Overland

(Zimmerman and Burton, 1979). Of particular note isthe Kelvin wave nature of the solution which is neitherresolved by the quasi-geostrophic approximation norby numerical weather prediction models with gridlengths greater than half the Rossby radius (Hsieh andGill, 1984). The Rossby wave mode should be important to the modification of atmospheric systems by thecoastal wall. A difficulty with the analysis, however, is the assertion that the offshore length scale is determined byhorizontal viscosity (section

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Angélique Melet, Jacques Verron, Lionel Gourdeau, and Ariane Koch-Larrouy

processes can explain modifications to the water masses of the Solomon Sea. The strong and vertically sheared WBC ( AM10 ) may lead to instabilities. Interactions of external tides with the topography give rise to strong internal tide generation and tidal energy dissipation in the Solomon Sea, as shown by different observational ( Egbert and Ray 2000 ) and numerical studies ( Jayne and St. Laurent 2001 ; Niwa and Hibiya 2001 ; Simmons et al. 2004 ; Arbic et al. 2004 ). These processes, as well as

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Florian Sévellec, Thierry Huck, Mahdi Ben Jelloul, Nicolas Grima, Jérôme Vialard, and Anthony Weaver

1. Introduction The ocean circulation is a slow component of the climate system and thus a major contributor to the system’s low-frequency variability. Moreover, global warming is likely to influence the oceans’ salinity distribution, and hence their dynamics, through the expected modification of the water cycle. Josey and Marsh (2005) have shown that an increase of the precipitation in the North Atlantic subpolar gyre has modified the sea surface salinity since the mid-1970s. Modifications

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W. D. Nowlin Jr. and C. A. Parker

ofships in the region, the number of weather reports, andthe mean air temperature and sea-air temperaturedifference averaged for available reports on each givenday. The lack of reports on 14-16 January likely resulted from rough sea conditions in the area. Themagnitude of the average air-sea temperature difference generally agrees with differences measured duringthe survey.3. Modifications to shelf watersa. Surface waters As an initial step in characterizing the waters beforeand after the passage

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Florian Sévellec, Thierry Huck, Mahdi Ben Jelloul, and Jérôme Vialard

into the ocean. Stochastic optimal perturbations are relevant to understanding how high-frequency atmospheric forcing related to midlatitude weather regimes [the North Atlantic Oscillation (NAO), for instance] can induce long-term variability of the thermohaline circulation. In addition, these analyses provide the upper bounds on the modification of the MOC. Some ocean models use constant fluxes for both heat and freshwater (“flux” boundary conditions), while others use fixed freshwater forcing and

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Hiroko Saito, Toshio Suga, Kimio Hanawa, and Nobuyuki Shikama

regions ( Fig. 1 ). There is a clue to the question about possible rapid modification of TRMW. Talley and Yun (2001) showed that salt-finger convection actively occurred in the upper part of the intrusion of Oyashio source water that substantially affected the properties of newly formed NPIW in the mixed water region. In the eastern subtropical region of the South Pacific, which is also the boundary region between different water masses, South Pacific Eastern Subtropical Mode Water (SPESTMW) formed

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Tal Ezer and Georges L. Weatherly

VOLUME20 JOURNAL OF PHYSICAL OCEANOGRAPHY JUNE1990A Numerical Study of the Interaction between a Deep Cold Jet and the Bottom Boundary Layer of the Ocean TAL EZER* AND GEORGES L. WEATHERLY*Department of Oceanography, Florida State University, Tallahassee, Florida(Manuscript received I May 1989, in final form 21 August 1989) ABSTRACT A two-dimensional (x-z) primitive equation model is

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