[gradsusr] what is the unit of moisture convergence?

[Kishore Ragi]

Dear users,

I can understand how to calculate moisture convergence with specific
humidity/mixing ratio but, I have relative humidity.

Could anybody please help me how to calculate moisture convergence with
relative humidity?

Thank you in advance,

Sincerely,

Kishore


On Thu, May 30, 2013 at 7:11 PM, Mohsen Soltani <soltani.clima at gmail.com>wrote:

> Dear Davide,
>
> It sounds logical! Thank you very much for your kindness.
>
> Mohsen
>
> --
> some are weather-wise some are otherwise!
> --
> Best Wishes,
> (Mr.) Mohsen Soltani
> Climatology Grad Student (M.Sc.),
> Faculty of Geography, University of Tehran, Tehran, Iran
> Tel: (+98) 9119772934
> e-mail: soltani.clima at gmail.com
>
>
> On Thu, May 30, 2013 at 2:54 AM, Davide Sacchetti <
> davide.sacchetti at arpal.gov.it> wrote:
>
>> specific humidity is defined as ratio of water vapor mass (g) over air
>> mass (kg) (units: g/kg)
>> mixing ratio is almost the same: ratio of water vapor mass (g) over DRY
>> air mass (kg) (units: g/kg)
>>
>> your divergence is like d(u*mixr)/dx, then has units of (m/s * g/kg)/m:
>> units should be g/kg*s-1
>>
>> bye bye
>> Davide
>>
>> On Thu, 2013-05-30 at 01:39 -0700, Mohsen Soltani wrote:
>> > Dear GrADS Users,
>> >
>> >
>> > I employed the following script to display the moisture convergence.
>> > But, I don't know what is the unit of the output! Please see the
>> > attached plot and let me know what's your opinion.
>> >
>> >
>> > ************************************************************************
>> > * rh    = Relative Humidity in %
>> > * t     = Temp at *set level in degrees Kelvin
>> > * tc    = Temp in degrees C
>> > * td    = Dewpoint at *set level in degrees C
>> > * e     = Vapor pressure
>> > * mixr  = Mixing ratio
>> > * u     = U-wind in m/s
>> > * v     = V-wind in m/s
>> > * mconv = moisture convergence/divergence.
>> >
>> >
>> > 'tc = (t-273.16)'
>> > 'td = tc-((14.55+0.114*tc)*(1-0.01*rh) + pow((2.5
>> > +0.007*tc)*(1-0.01*rh),3) + (15.9+0.117*tc)*pow((1-0.01*rh),14))'
>> > 'vapr = 6.112*exp((17.67*td)/(td+243.5))'
>> > 'e = vapr*1.001+(lev-100)/900*0.0034'
>> > 'mixr = 0.62197*(e/(lev-e))*1000'
>> > 'mconv = (1)*hdivg(u*mixr,v*mixr)*1e4'
>> > 'd mconv'
>> > ********************************************************
>> >
>> >
>> >
>> >
>> > Thank you,
>> > Mohsen
>> >
>> >
>> > --
>> > some are weather-wise some are otherwise!
>> > --
>> > Best Wishes,
>> > (Mr.) Mohsen Soltani
>> > Climatology Grad Student (M.Sc.),
>> > Faculty of Geography, University of Tehran, Tehran, Iran
>> > Tel: (+98) 9119772934
>> > e-mail: soltani.clima at gmail.com
>> >
>> > _______________________________________________
>> > gradsusr mailing list
>> > gradsusr at gradsusr.org
>> > http://gradsusr.org/mailman/listinfo/gradsusr
>>
>> --
>> --> Attenzione cambio indirizzo: davide.sacchetti at arpal.gov.it
>> --
>> Davide Sacchetti
>> Centro Funzionale Meteo Idrologico di Protezione Civile della Regione
>> Liguria
>> ARPAL Unità Tecnica Complessa di livello Regionale
>> V.le Brigare Partigiane 2 16121 Genova (I)
>> tel: +39 010 6437535                    fax: +39 010 6437520
>> mail: davide.sacchetti at arpal.gov.it     web: www.meteoliguria.it
>>
>>
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>
>
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