<div dir="ltr"><div>Thanks again Jody,</div><div>It was really helpful, for the last question about this issue, Do I need nonHydrostatic=.True. for the simulation of Eddies? Isn't that a fine-scale phenomena? will MIT show up Eddies at 2-degree resolution?</div><div><br></div><div>Thanks,</div><div> Saeid</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Aug 15, 2017 at 12:42 PM, Jody Klymak <span dir="ltr"><<a href="mailto:jklymak@uvic.ca" target="_blank">jklymak@uvic.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><u></u>
<div>
<div style="font-family:sans-serif"><span class=""><div style="white-space:normal">
<p dir="auto">On 15 Aug 2017, at 9:29, Saeid Esmaeilpour wrote:</p>
<p dir="auto"></p></div>
<div style="white-space:normal"><blockquote style="border-left:2px solid #5855d5;color:#5855d5;margin:0 0 5px;padding-left:5px"><p dir="auto">Jody,<br>
my model is about The simulation of currents Circulation from surface to<br>
depth in indian Ocean, and I selected nonHydrostatic=.TRUE., cause I<br>
think the model resolve the Nonlinear terms with nonHydrastatic=True (am I<br>
wrong ?). If I select nonHydrastatic=True, in this case how much should I<br>
set for cg3MaxIters? and If select nonHydrastatic=False, how much for that?<br>
basically for the simulation of currents Circulation and at 2-degree I have<br>
to take non Hydraustatic=false?</p>
</blockquote></div>
</span><div style="white-space:normal">
<p dir="auto"><code>nonHydrostatic=.True.</code> solves the non-hydrostatic equation for dw/dt, which essentially means the pressure needs to be determined globally from a Poisson equation, and hence the 3-D solver. <code>.False.</code> means that pressure is solved using the hydrostatic approximation (if you don’t know what this is, Google plus a basic GFD course would help).</p>
<p dir="auto">This really has nothing to do with non-linearity until you start resolving scales where the hydrostatic approximation breaks down (basically dw/dt is no longer << rho’g / rho_0). </p>
<p dir="auto">You really only need non-hydrostatic approximation for fine-scale runs looking at internal waves, dense overflows, convection, or other turbulent phenomena. None of which will show up at 2-degree resolution.</p>
<p dir="auto">Cheers, Jody</p>
<p dir="auto"></p></div>
<div style="white-space:normal"><blockquote style="border-left:2px solid #5855d5;color:#5855d5;margin:0 0 5px;padding-left:5px"><span class=""><p dir="auto">Thanks again,<br>
Saeid<br>
<br>
On Tue, Aug 15, 2017 at 11:59 AM, Jody Klymak <<a href="mailto:jklymak@uvic.ca" target="_blank">jklymak@uvic.ca</a>> wrote:<br>
</p>
</span><blockquote style="border-left:2px solid #5855d5;color:#00afcc;margin:0 0 5px;padding-left:5px;border-left-color:#00afcc"><p dir="auto"><span class="">Hi Saied,<br>
<br>
cg3dMaxIters is only used if nonHydrostatic=.True.. You aren’t resolving<br>
any non-hydrostatic physics at 2-degree resolution, so I would suggest<br></span>
setting nonHydrostatic=.False. Your model runs will be *much* faster.</p><div><div class="h5"><br>
<br>
Cheers, Jody<br>
<br>
On 15 Aug 2017, at 8:43, Saeid Esmaeilpour wrote:<br>
<br>
Hi Dear users,<br>
could someone please explain to me what are the following PARM02?<br>
when I increase cg3dMaxIters from 50 to 400 (e.g,. cg3dMaxIters=400) the<br>
run speed becomes very slowly. how can I select this value? what's the<br>
criteria for selecting this number? My domain is 510*210 with 20layer and<br>
also my resolution is 2 degree (3704m).<br>
<br>
# Elliptic solver parameters<br>
&PARM02<br>
cg2dMaxIters=1000,<br>
cg2dTargetResidual=1.E-13,<br>
cg3dMaxIters=400,<br>
cg3dTargetResidual=1.E-13,<br>
<br>
Thanks for any help,<br>
Saeid<br>
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