FastFind »   Lastname: doi:10.1029/ Year: Advanced Search  

AGU: Journal of Geophysical Research, Oceans

 

Keywords

  • comparison observations and models
  • Indian Ocean
  • Mozambique Channel

Index Terms

  • Computational Geophysics: Model verification and validation
  • Oceanography: Physical: Currents
  • Oceanography: Physical: Eddies and mesoscale processes
  • Oceanography: General: Time series experiments
  • Oceanography: Physical: General circulation
Abstract
Cited By (0)
 

Abstract

Comparison between observations and models of the Mozambique Channel transport: Seasonal cycle and eddy frequencies

P. M. van der Werf

Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Utrecht, Netherlands

P. J. van Leeuwen

Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Utrecht, Netherlands

Department of Meteorology, University of Reading, Reading, UK

H. Ridderinkhof

Royal Netherlands Institute for Sea Research, Texel, Netherlands

W. P. M. de Ruijter

Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Utrecht, Netherlands

A time series of the observed transport through an array of moorings across the Mozambique Channel is compared with that of six model runs with ocean general circulation models. In the observations, the seasonal cycle cannot be distinguished from red noise, while this cycle is dominant in the transport of the numerical models. It is found, however, that the seasonal cycles of the observations and numerical models are similar in strength and phase. These cycles have an amplitude of 5 Sv and a maximum in September, and can be explained by the yearly variation of the wind forcing. The seasonal cycle in the models is dominant because the spectral density at other frequencies is underrepresented. Main deviations from the observations are found at depths shallower than 1500 m and in the 5/y–6/y frequency range. Nevertheless, the structure of eddies in the models is close to the observed eddy structure. The discrepancy is found to be related to the formation mechanism and the formation position of the eddies. In the observations, eddies are frequently formed from an overshooting current near the mooring section, as proposed by Ridderinkhof and de Ruijter (2003) and Harlander et al. (2009). This causes an alternation of events at the mooring section, varying between a strong southward current, and the formation and passing of an eddy. This results in a large variation of transport in the frequency range of 5/y–6/y. In the models, the eddies are formed further north and propagate through the section. No alternation similar to the observations is observed, resulting in a more constant transport.

Received 10 July 2009; accepted 15 October 2009; published 3 February 2010.

Citation: van der Werf, P. M., P. J. van Leeuwen, H. Ridderinkhof, and W. P. M. de Ruijter (2010), Comparison between observations and models of the Mozambique Channel transport: Seasonal cycle and eddy frequencies, J. Geophys. Res., 115, C02002, doi:10.1029/2009JC005633.

Cited By

Please wait one moment ...