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<div class="moz-cite-prefix">Where the concept is relevant (with an
enormous number of caveats, yes) is to answer the fundamental
question, will TC interaction with baroclinicity, induce
transition to a growing or stable baroclinic system (often
observed) or will the TC perturbation just damp out (also often
observed) with a theoretically expected but hard to actually point
out, increase in baroclinic available potential energy for some
future perturbation to extract.<br>
<br>
I am obviously not an expert either (and my M.S is 31 years
stale) and I did sleep at home last night, not in a Holiday Inn
Express but I think it is a tractable forecast and theoretical
modeling problem, again with the caveats mentioned below.<br>
<br>
Casually plugging this into a program without understanding the
concepts is worrisome, also agreed.<br>
<br>
Thanks everyone for the response!<br>
<br>
On 02/09/2018 10:25 AM, Dennis Shea wrote:<br>
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<div>I am not really knowledgeable about Eady Growth Rate
(EGR) so I asked a person and got the following response:<br>
--------<br>
<div>
<div>
<div>Hi Dennis,<br>
<br>
</div>
Ha! When I google Eady growth rate, the first thing
that comes up is your NCL function and the second thing
that comes up are some class notes that I wrote when I
taught a course. Apparently we are the state of
knowledge on Eady growth rate, which is slightly
concerning.<br>
<br>
</div>
Erm, for [1] I don't think the Eady model is intended to
tell you something about tropical cyclone environments.
It's really intended to describe the growth of
mid-latitude eddies. Since it's formulated on an f-plane,
I don't think it's really appropriate for use in tropical
environments. That being said, the eady growth rate
really is just a measure of baroclinicity so it might be
fine to determine what the baroclinicity is in their
tropical cyclone environments. <br>
</div>
<div><br>
</div>
<div>For [2b] I'd say no too. But I don't think using
equivalent potential temperature would work either. I
think you'd have to include a diabatic heating term in the
thermodynamic equation that's being solved to account for
the release of heat associated with the convergence of
moisture and precipitation that accompanies the growing
wave. WIth my expert googling skils, I came across
this... <a
href="https://iri.columbia.edu/%7Etippett/pubs/moist.pdf"
target="_blank" moz-do-not-send="true">https://iri.columbia.edu/~<wbr>tippett/pubs/moist.pdf</a></div>
<div><br>
</div>
For [2a] I don't really know the answer. But I'm also not
sure how you would measure the real world growth rates. The
eady model is intended to describe the growth of the normal
modes and I think you could compare the predictions with a
normal mode calculation using the real world basic state but
I'm not sure how you would actually measure the growth rates
of the real world. I also think it might give you a
dimensionless growth rate which tells you what scales
dominate by growing fastest, but I'm not sure to what extent
it is something that can be compared with the real world.
In short, I don't really know. <br>
-----------<br>
</div>
HTH<br>
</div>
D<br>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Feb 7, 2018 at 10:56 AM, George
Vandenberghe <span dir="ltr"><<a
href="mailto:george.vandenberghe@noaa.gov" target="_blank"
moz-do-not-send="true">george.vandenberghe@noaa.gov</a>></span>
wrote:<br>
<blockquote class="gmail_quote">
<div class="HOEnZb">
<div class="h5">On 02/07/2018 12:47 PM, Prashanth
Bhalachandran wrote:<br>
<blockquote class="gmail_quote">
Hello all,<br>
I want to compare the baroclinity of two tropical
cyclone environments. What is the best way to do this
using NCL?<br>
<br>
I did some digging and found a function to calculate
Eady growth rate in v6.4 . I have never used it thus
far, so I want to know what the options are.<br>
<br>
Thank you,<br>
Prashanth<br>
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Okay this is tangential to the topic but VERY INTERESTING in
its own right. How well do the observed growth rates<br>
<br>
for (presumably large scale because small length scale
damps) compare with the theoretical Eady growth rates<br>
<br>
and (something I should know but don't) do Eady growth rates
incorporate the effect of moisture on stratification?
<div class="HOEnZb">
<div class="h5"><br>
<br>
<br>
<br>
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<br>
</div>
</blockquote>
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