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Water-mass transformations in a neutral density framework and the key role of light penetration

By Daniele Iudicone, Gurvan Madec and Trevor J. McDougall


A new formulation is proposed for the evaluation of the dianeutral transport in the ocean. The method represents an extension of the classical diagnostic approach for estimating the water-mass formation from the buoyancy balance. The inclusion of internal sources such as the penetrative solar shortwave radiation (i.e., depth-dependent heat transfer) in the estimate of surface buoyancy fluxes has a significant impact in several oceanic regions, and the former simplified formulation can lead to a 100% error in the estimate of water-mass formation due to surface buoyancy fluxes. Furthermore, internal mixing can also be overestimated in inversions of in situ data when the shortwave radiation is not allowed to be penetrative.<br/>The method examines the evolution equation of neutral density via the tendencies of potential temperature and salinity. The neutral density framework does not require the choice of a reference pressure and thus, unlike previous approaches that consider potential density, it is well suited for examining the whole open-ocean water column.<br/>The methodology is easy to implement, particularly for ocean numerical models. The authors present here its application to a long simulation made with an ice–ocean global model, which allowed the method to be validated.<br/

Topics: GC
Year: 2008
OAI identifier:
Provided by: e-Prints Soton

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  17. (2001). Mode waters. Ocean Circulation and Climate: Observing and Modelling the Global
  18. (1990). Neutral surfaces and potential vorticity in the world’s oceans.
  19. (1988). Neutral-surface potential vorticity.
  20. (1996). Ocean mixed layer radiant heating and solar penetration: A global analysis.
  21. (2000). Ocean radiant heating.
  22. (2001). Ocean surface water mass transformation. Ocean Circulation and Climate: Observing and Modelling the Global
  23. (1972). On properties of seawater defined by temperature, salinity, and pressure.
  24. (1988). On the helical nature of neutral trajectories in the ocean.
  25. (1982). On the relation between sea-surface heat flow and thermal circulation in the ocean.
  26. (2005). On the representation of high latitude processes in the ORCA-LIM global coupled sea ice-ocean model.
  27. (1986). On the role of interior mixing and air–sea fluxes in determining the stratification and circulation of the oceans.
  28. (1999). OPA 8.1 ocean general circulation model reference manual. Notes du Pôle de modélisation, Institut Pierre-Simon Laplace,
  29. Parameterizing solar radiation transmission through the upper ocean.
  30. (2003). Potential feedbacks between Pacific Ocean ecosystems and interdecadal climate variations.
  31. (2005). Rapid climate change and conditional instability of the glacial deep ocean from the thermobaric effect and geothermal heating.
  32. (1992). Rates of water mass formation in the North Atlantic Ocean.
  33. (1999). Reconciling thermodynamic and dynamic methods of computation of water-mass transformation rates. Deep-Sea Res.
  34. (2005). Seasonal variability of the mixed layer depth in the Mediterranean Sea as derived from in situ profiles.
  35. (2004). Shallow overturning circulations of the tropical-subtropical oceans. Earth’s Climate: The Ocean–Atmosphere Interaction,
  36. (1995). Solar radiation, phytoplankton pigments and the radiant heating of the equatorial Pacific warm pool.
  37. (2003). Study of the impact of the geothermal heating on ORCA model deep circulation deduced from natural helium-3 simulations.
  38. (1995). The influence of ocean mixing on the absolute velocity vector.
  39. (2008). The material derivative of neutral density.
  40. (2003). The Pacific cold tongue: A pathway for interhemispheric exchange.
  41. (1995). The relationship between water mass formation and the surface buoyancy flux, with application to Phillips’ Red Sea model.
  42. (1984). The relative roles of diapycnal and isopycnal mixing on subsurface water mass conversion.
  43. (2008). The role of Southern Ocean surface forcings and mixing in the global conveyor.
  44. (2001). The Southern Ocean limb of the global deep overturning circulation.
  45. (1987). Thermobaricity, cabbeling, and water-mass conversion.
  46. (2004). Vertical mixing, energy, and the general circulation of the oceans.
  47. (2000). Volume and mass transport across isosurfaces of a balanced fluid property.
  48. (1995). Water mass formation from revised COADS data.
  49. (2005). Water mass transformation and subduction in the South Atlantic.
  50. (2000). Water mass transformation in the Southern Ocean of a global isopycnal coordinate GCM.

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