Search Results

You are looking at 1 - 2 of 2 items for :

  • Author or Editor: R. Mazé x
  • Journal of Physical Oceanography x
  • Refine by Access: Content accessible to me x
Clear All Modify Search
A. Pichon and R. Mazé

Abstract

Data collected on Cruise ONDINE 85 organized by the Service Hydrophique et Ocèanographique de la Marine, at two points (P1 and P6) near the continental shelf break of the Bay of Biscay, show very large amplitudes of internal tides. These waves exhibit a strong nonlinear character of the semidiurnal evolution of the thermocline depth. During spring tide, the internal oscillations can reach 80 meters.

In order to get an analytical solution for the interface depth variation near the top of the shelf break, the two layer nonlinear model of generation and propagation of internal tides developed by Mazé is linearized in the present paper.

Taking account of several monochromatic tides waves (M2, S2, N2, K2) in the forcing term, comparison between this analytical solution and data can be done over. a six-week period. Such a comparison shows that that the scale of the interface level and the time variation of the interface are quite well reproduced by the analytical model.

Full access
Ivana Cerovečki, Lynne D. Talley, Matthew R. Mazloff, and Guillaume Maze

Abstract

Subantarctic Mode Water (SAMW) is examined using the data-assimilating, eddy-permitting Southern Ocean State Estimate, for 2005 and 2006. Surface formation due to air–sea buoyancy flux is estimated using Walin analysis, and diapycnal mixing is diagnosed as the difference between surface formation and transport across 30°S, accounting for volume change with time. Water in the density range 26.5 < σθ < 27.1 kg m−3 that includes SAMW is exported northward in all three ocean sectors, with a net transport of (18.2, 17.1) Sv (1 Sv ≡ 106 m3 s−1; for years 2005, 2006); air–sea buoyancy fluxes form (13.2, 6.8) Sv, diapycnal mixing removes (−14.5, −12.6) Sv, and there is a volume loss of (−19.3, −22.9) Sv mostly occurring in the strongest SAMW formation locations. The most vigorous SAMW formation is in the Indian Ocean by air–sea buoyancy flux (9.4, 10.9) Sv, where it is partially destroyed by diapycnal mixing (−6.6, −3.1) Sv. There is strong export to the Pacific, where SAMW is destroyed both by air–sea buoyancy flux (−1.1, −4.6) Sv and diapycnal mixing (−5.6, −8.4) Sv. In the South Atlantic, SAMW is formed by air–sea buoyancy flux (5.0, 0.5) Sv and is destroyed by diapycnal mixing (−2.3, −1.1) Sv. Peaks in air–sea flux formation occur at the Southeast Indian and Southeast Pacific SAMWs (SEISAMWs, SEPSAMWs) densities. Formation over the broad SAMW circumpolar outcrop windows is largely from denser water, driven by differential freshwater gain, augmented or decreased by heating or cooling. In the SEISAMW and SEPSAMW source regions, however, formation is from lighter water, driven by differential heat loss.

Full access