Journal of Tropical Oceanography ›› 2013, Vol. 32 ›› Issue (2): 37-46.doi: 10.11978/j.issn.1009-5470.2013.02.004cstr: 32234.14.j.issn.1009-5470.2013.02.004

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The spatial distribution of sources and sinks of ocean mesoscale eddies

XU Chi1, 2, CHEN Gui-ying1, SHANG Xiao-dong1, HUANG Rui-xin3   

  1. 1. State Key Laboratory of Oceanography in Tropics (South China Sea Institute of Oceanology), Chinese Academy of Sciences, Guangzhou 510301, China; 2. University of the Chinese Academy of Sciences, Beijing 100049, China; 3. Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
  • Received:2012-01-31 Revised:2013-06-10 Online:2013-06-10 Published:2013-06-10

Abstract:

The difference between eddy formation and termination, based on eddy detection and tracking using 16-year satellite altimetry data, suggests both eddy formation and termination occur in the world oceans, except at the equator. There is no evidence of formation-dominant zone or termination-dominant zone in the open oceans, and along the eastern boundaries of the ocean basins eddy formation overpowers eddy dissipation while along the western boundaries eddy decaying overpowers eddy formation. A two-layer model is formulated, using the equivalent depth of the first baroclinic mode as the interface depth and assuming the barotropic mode and the first baroclinic mode have equal kinetic energy. We estimated the annual mean eddy energy change rate and the associated distribution of sources and sinks of mesoscale eddy energy. In addition, although dissipation of eddy energy is the dominating term within the western boundaries, intense dissipation also occurs in the ocean interior, in particular near intense currents and associated recirculation regimes. Furthermore, the distribution of the number of eddies generated minus decayed and the pattern of eddy-energy sources and sinks demonstrate that, although there are more eddies formed in the narrow bands of eastern boundaries, eddy energy growth rate in these regions is quite low due to weak mesoscale variability.

Key words: mesoscale eddy, eddy kinetic energy, eddy available gravitational potential energy, western boundary, dissipation

CLC Number: 

  • P731