[ncl-talk] About CAPE and CIN for soundings

[Dennis Shea]

Forgot:

http://www.cgd.ucar.edu/~shea/skewT.f

This has all the codes used for the skewT diagram ...

HTH

On Mon, Apr 11, 2016 at 9:17 AM, Dennis Shea <shea at ucar.edu> wrote:

> CAPE **is** sensitive to the starting LCL.
>
> About 17 years ago, I tested a number of CAPE codes and the calculated
> values varied 'considerably'. To be honest, I have forgotten why I chose
> the version I put into NCL. I would be open to altering the code or
> including a different one if you can substantiate and document the issues.
>
> --
>
> A number of CAPE (mainly fortran) subroutines are at:
>     http://www.cgd.ucar.edu/~shea/CAPE/*
>     http://www.cgd.ucar.edu/~shea/rip_cape.f
>
>     The capeThermo.f is the one used by NCL (see: subroutine cape_djs)
>
>     The rip_cape.f was originally written by Mark Stoelinga, U. Washington
>      http://www2.mmm.ucar.edu/wrf/users/docs/ripug.htm
>
> Also, you can download all of Kerry Emanuel's codes from:
>
>      ftp://texmex.mit.edu/pub/emanuel/BOOK/
>
> ===
> NOTE: WRF provides two functions. These call rip_cape.f
>
>
> ===
> Let ncl-talk know if you need more information.
>
> Cheers
> D
>
> On Mon, Apr 11, 2016 at 5:19 AM, Stavros Dafis <sdafis at cc.uoi.gr> wrote:
>
>> Dear users,
>>
>> I am trying to find the Fortran code that calculates CAPE, as I cannot
>> find it
>> in my libraries (I am using ncl 6.2.0). I want to try and fix the problem
>> with
>> the excessive CAPE and also find the CIN from sounding data. Is there any
>> ready
>> program to calculate CIN as the cape_thermo one?
>>
>> I am plotting real data from soundings and I have also noticed the
>> problem with
>> CAPE. The LCL calculated by ncl is always lower than the actual one and EL
>> quite higher.
>>
>> I do not understand why ncl adjusts the LCL higher than the first guess,
>> as I
>> saw these lines while debugging the code:
>>
>>
>> cape.f: LCL pressure: original    915.26794433593750       mb
>> cape.f: adjusted to    925.00000000000000       mb
>> cape.f: and lies at level            4
>>
>>
>> In my data, the actual LCL is at 879mb, but 915mb would be better than
>> 925mb.
>> Anyway, I need to see the Fortran code to find the problem. Any
>> suggestions on
>> that? Choose the second guess of LCL?
>>
>> Furthermore, I would like to propose the following changes at the
>> skewt_func.ncl
>> code, in order the users to find the LFC and Equillibrium levels, because
>> they
>> are already calculated but not printed:
>>
>>
>>
>>   iprnt = 0   ; debug only (>0)
>>    nlLcl= 0   ; LCL
>>    nlLfc= 0   ; LFC
>>  nlCross= 0   ; EL
>>
>>  cape = cape_thermo(p,tc,plcl,iprnt)       ; (J/kg)
>>
>>   tpar = cape at tparcel                      ; temp of the parcel
>>   nlLcl= cape at jlcl
>>   nlLfc= cape at jlfc
>>   nlCross= cape at jcross
>>                                           ; Equillibrium Level
>> EL_p = p(nlCross)                         ; hPa
>> EL_z = z(nlCross) /1000                   ; in km
>> EL = decimalPlaces(EL_z,1,True)
>> print("EL = "+EL+" km")
>>
>> LFC_p = p(nlLfc)                         ; LFC in hPa
>> LFC_z = z(nlLfc) /1000                   ; in km
>> LFC = decimalPlaces(LFC_z,2,True)
>> print("LFC = "+LFC+" km")
>>
>>
>>
>> --
>> Stavros Dafis
>> MSc student Atmospheric Sciences and Environment
>> University of Ioannina
>> LATMOS Laboratoire Atmospheres, Milieux,Observations Spatiales;
>> Versailles,
>> France.
>> Tel: +30 2651008499,  Mobile: +30 6970420242
>> e-mails: sdafis at noa.gr or dafis91 at yahoo.gr or sdafis at cc.uoi.gr
>> Weather charts: http://www.metar.gr
>> http://www.meteovolos.gr
>>
>>
>>
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>>
>
>
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