- APE Diagnostic Software - Rossby Wave activity Flux

Script:         rossby_wave_activity_flux.gs
Text document:  rossby_wave_activity_flux.txt

Authors:        Kazuaki Nishii and Hisashi Nakamura
                December 2007
                September 2011 : bug-fix supplied by Kazuaki Nishii

This is a GrADS script for evaluating the horizontal component of a Rossby wave activity flux defined by Takaya and Nakamura (2001). By setting the background meridional velocity to be zero, you can evaluate Plumb's (1985) flux. The former is designed for a particular framework where anomalies from zonally-varying time-mean flow are regarded as stationary Rossby waves, while the latter is suited for representing propagation of planetary waves in the zonally-uniform westerlies.

The script was written by Kazuaki Nishii, a postdoc working with Hisashi Nakamura. Hopefully, it is useful for those who are looking at experiments with zonally asymmetric SST distributions. The script is designed for application to one of the IPCCC-AR4 models, but it can easily be modified for application to the APE experiments.

Please contact the authors if you have any question on the script.
Hisashi Nakamura: hisashi(AT)eps.s.u-tokyo.ac.jp

References

Plumb, R.A., 1985: On the Three-Dimensional Propagation of Stationary Waves. J. Atmos. Sci., 42, 217-229. DOI link

Takaya, K., and H. Nakamura, 2001: A Formulation of a Phase-Independent Wave-Activity Flux for Stationary and Migratory Quasigeostrophic Eddies on a Zonally Varying Basic Flow. J. Atmos. Sci., 58, 608-627. DOI link