[ncl-talk] Fwd: Computing apparent heat source from reanalysis data

[Lyndz]

Dear Sir Dennis and NCL experts,

Thank you for sending the script about this.

I still have one question about the units of the following line:


  Q1 = Cp*dTdt - Cp*(omega*ss-advT)
  Q1 at long_name = "Total Diabatic Heating as the Apparent Heat Source"
  Q1 at units     = "K/s"

>From dimensional analysis:

Cp = J/K*kg
dTdt = K/s
omega = Pa/s
ss = K/Pa
advT = K/s

Q1=(J/Kkg)*K/s - (J/Kkg)*(Pa/s*(K/Pa) - K/s)

Therefore the unit of Q1 should be J/kg/s (Joules per kg per second)?

I would like the unit of Q1 to be in W/m2. I will still need to integrate
it vertically.

I'll appreciate any help about this.

Sincerely,
Lyndz





---------- Forwarded message ---------
From: Dennis Shea <shea at ucar.edu>
Date: Mon, Sep 9, 2019 at 12:17 PM
Subject: Re: [ncl-talk] Computing apparent heat source from reanalysis data
To: Lyndz <olagueralyndonmark429 at gmail.com>


Yes. All arrays MUST have the same orientation.
Please look at what I sent.
=====
You must be careful with units.

Please ... questions only to ncl-talk.
===============
The attached is a sketch of calculating Q1 and Q2.  It is not tested!

You can use this as a template of how to proceed.
Again, you must be careful with units.

That is your responsibility.




On Sun, Sep 8, 2019 at 9:04 PM Lyndz <olagueralyndonmark429 at gmail.com>
wrote:

> Dear Sir Dennis,
>
> Thank you for your help.
>
> I have another question about the equation Q = Cp*dTdt -
> Cp*(omega*s1+advTcfd).
>
> I inverted the orientation for the latitude (N-S) when I computed *advTcfd
> *using the ::-1.
> Do I also need to do this when computing dTdt?
>
>
> Sincerely,
>
> On Mon, Sep 9, 2019 at 11:58 AM Dennis Shea <shea at ucar.edu> wrote:
>
>> Change:
>>    s1   = static_stability (pc, temp, 0, 0)
>> To:
>>    s1  = static_stability (pc, temp, 1, 0)
>>
>> Or, replace the 'conform' and the above 's1' use:
>>
>>    s1  = static_stability (p , temp, 1, 0)
>>
>> =====
>> %> ncl heatsource.ncl
>>
>>
>>
>> On Fri, Sep 6, 2019 at 6:25 AM Lyndz via ncl-talk <ncl-talk at ucar.edu>
>> wrote:
>>
>>> Dear NCL experts,
>>>
>>> *[Details]*
>>> I am calculating the apparent heat source from NCEP R2 reanalysis data
>>> following the equation of Yanai et al. (1973) as in the attached image (
>>> https://renqlsysu.github.io/2019/02/01/apparent_heat_source/)
>>>
>>> I have uploaded my files in my dropbox for verification:
>>>
>>> https://www.dropbox.com/sh/jx6gr9huan5v7lp/AADDr0pULF3cmMgP7LMVQVCma?dl=0
>>>
>>>
>>> *[Problem]*
>>> Attached in this email is the script that I am currently working on. It
>>> runs fine but the values of the apparent heat source is *-Inf* for all
>>> grid points.
>>>
>>> I would like to ask for suggestions on how to compute this correctly in
>>> NCL.
>>>
>>> Sincerely,
>>>
>>> Lyndz
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>
>>
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