Japan Geoscience Union Meeting 2016

Presentation information


Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS10] Geophysical fluid dynamics-Transfield approach to geoscience

Mon. May 23, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Keita Iga(Atmosphere and Ocean Research Institute, The University of Tokyo), Kensuke Nakajima(Department of Earth and Planetary Sciences,Flculty of Sciences,Kyushu University), Shigeo Yoshida(Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University), Takatoshi Yanagisawa(Department of Deep Earth Structure and Dynamics Research, Japan Agency for Marine-Earth Science and Technology), Hidenori Aiki(Japan Agency for Marine-Earth Science and Technology)

5:15 PM - 6:30 PM

[MIS10-P03] A seamlessly diagnosable expression for the energy flux of all waves at all latitudes with equatorial and coastal waveguides

*Hidenori AIKI1, Richard J Greatbatch2 (1.Nagoya University, 2.GEOMAR / Univ. of Kiel)

Keywords:group velocity, equatorial waves

Some of Rossby waves in the mid-latitude regions of the ocean originate from waves propagating poleward along the eastern boundaries, that may be traced back to the arrival of equatorial Kelvin waves. This kind of interaction between the various types of free waves in the equatorial and mid- latitude regions is fundamental for understanding tropical climate systems, and has sometimes been explained using the concept of equatorial basin mode. In previous studies, the interaction of equatorial and mid-latitude waves has been little mentioned in terms of the transfer of wave energy. The present study provides a formula to calculate the energy flux, from model outputs without relying on a Fourier analysis. The expression of the energy flux of the present study has been determined from the analysis of the group velocity of equatorial Rossby, mixed Rossvy-gravity, and inertia-gravity waves. The result is that the energy flux is written as the sum of the pressure flux and the additional rotational flux. The expression of the additional rotational flux reduces, under the approximation of mid-latitude Rossby waves, to that has been derived in previous studies and, under the approximation of mid-latitude inertia-gravity waves, to zero. Thus the expression of the energy flux, as given by the present study, may be used for a seamless diagnosis of waves in both equatorial and mid-latitude regions.