Study of the equatorial Atlantic Ocean mixing layer using a one-dimensional turbulence model

Authors

  • Udo Tersiano Skielka Universidade de São Paulo; Instituto de Astronomia, Geofísica e Ciências Atmosféricas; Departamento de Ciências Atmosférica
  • Jacyra Soares Universidade de São Paulo; Instituto de Astronomia, Geofísica e Ciências Atmosféricas; Departamento de Ciências Atmosférica
  • Amauri Pereira de Oliveira Universidade de São Paulo; Instituto de Astronomia, Geofísica e Ciências Atmosféricas; Departamento de Ciências Atmosférica

DOI:

https://doi.org/10.1590/S1679-87592010000700008

Keywords:

Oceanic turbulence, General ocean turbulence model, Equatorial Atlantic Ocean, Turbulent kinetic energy

Abstract

The General Ocean Turbulence Model (GOTM) is applied to the diagnostic turbulence field of the mixing layer (ML) over the equatorial region of the Atlantic Ocean. Two situations were investigated: rainy and dry seasons, defined, respectively, by the presence of the intertropical convergence zone and by its northward displacement. Simulations were carried out using data from a PIRATA buoy located on the equator at 23º W to compute surface turbulent fluxes and from the NASA/GEWEX Surface Radiation Budget Project to close the surface radiation balance. A data assimilation scheme was used as a surrogate for the physical effects not present in the one-dimensional model. In the rainy season, results show that the ML is shallower due to the weaker surface stress and stronger stable stratification; the maximum ML depth reached during this season is around 15 m, with an averaged diurnal variation of 7 m depth. In the dry season, the stronger surface stress and the enhanced surface heat balance components enable higher mechanical production of turbulent kinetic energy and, at night, the buoyancy acts also enhancing turbulence in the first meters of depth, characterizing a deeper ML, reaching around 60 m and presenting an average diurnal variation of 30 m.

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Published

2010-06-01

How to Cite

Skielka, U. T., Soares, J., & Oliveira, A. P. de. (2010). Study of the equatorial Atlantic Ocean mixing layer using a one-dimensional turbulence model . Brazilian Journal of Oceanography, 58(spe3), 57-69. https://doi.org/10.1590/S1679-87592010000700008

Issue

Section

naodefinida