| 1 | 
heimbach | 
1.1 | 
A 1/3 {$^\circ$} resolution model of the tropical Pacific Ocean is  | 
| 2 | 
  | 
  | 
used to investigate eddy energetics associated with tropical  | 
| 3 | 
  | 
  | 
instability waves (TIWs) in the equatorial Pacific Ocean from 1996  | 
| 4 | 
  | 
  | 
to 2000. The geographical dependence of the balance of the perturbation | 
| 5 | 
  | 
  | 
energy equation is explored, and the sensitivity of the results to | 
| 6 | 
  | 
  | 
the wind forcing and the model's resolution is investigated. | 
| 7 | 
  | 
  | 
 | 
| 8 | 
  | 
  | 
Eddy kinetic energy reaches large values in fall 1998  | 
| 9 | 
  | 
  | 
during La Nina and TIWs are absent during El Nino (spring 1997 to  | 
| 10 | 
  | 
  | 
spring 1998).  At 135$^{\circ}$W, the large mean to eddy kinetic  | 
| 11 | 
  | 
  | 
energy conversion is dominated by $\overline{u'v'} \partial  | 
| 12 | 
  | 
  | 
U/\partial y$, $\overline{v'v'}\partial V/\partial y$ and  | 
| 13 | 
  | 
  | 
$\overline{u'w'}\partial U/\partial z$. All those terms are  | 
| 14 | 
  | 
  | 
subject to seasonal and interannual variability. Baroclinic instability also  | 
| 15 | 
  | 
  | 
provides energy to the TIWs between 1$^{\circ}$ and 4$^{\circ}$N through the | 
| 16 | 
  | 
  | 
conversion of eddy potential to eddy kinetic energy.  | 
| 17 | 
  | 
  | 
 | 
| 18 | 
  | 
  | 
Largest eddy energy production are observed in surface at 4$^{\circ}$N within  | 
| 19 | 
  | 
  | 
the anticyclonic shear between the SEC and the NECC, where the eddy kinetic energy  | 
| 20 | 
  | 
  | 
is maximum. $\overline{u'v'}\partial U/\partial y$ is maximum just north of the equator  | 
| 21 | 
  | 
  | 
at about 50\,m in fall 1996 while it is maximum at the surface  | 
| 22 | 
  | 
  | 
in fall 1998 and fall 1999, suggesting that the TIWs derive their energy  | 
| 23 | 
  | 
  | 
from the EUC-SEC shear in 1996 and from the shear within the SEC in 1998  | 
| 24 | 
  | 
  | 
and 1999. $\overline{v'v'}\partial V/\partial y$ and $\overline{u'w'}\partial  | 
| 25 | 
  | 
  | 
U/\partial z$, which generally tend to weaken the waves just to the north  | 
| 26 | 
  | 
  | 
of the equator, are also subject to interannual variability and their combination  | 
| 27 | 
  | 
  | 
with $\overline{u'v'}\partial U/\partial y$ lead to weaker TIWs in fall  | 
| 28 | 
  | 
  | 
1996 compared to fall 1998 and 1999.  | 
| 29 | 
  | 
  | 
 | 
| 30 | 
  | 
  | 
 |