[ncl-talk] Regarding vertically integrated Moisture flux divergence

Dennis Shea shea at ucar.edu
Fri Jun 29 07:30:45 MDT 2018

```I have not spent much time on this.

[1] You are integrating using hPa as opposed to Pa [ a factor or 100[]
[2] You are using monthly mean quantities. While 'mechanically' you can do
this, it is not the correct methodology. Quantities like *u*q* and *v*q *are
*nonlinear*. The correct approach is to use the very high frequency [say,
6-hrly or, at least, daily mean values of u, v and q] and compute the
monthly means from the products of those quantities. Using the monthly mean
U, V, Q *might* yield reasonable patterns but the numbers are not the
correct ones.

Cheers

On Wed, Jun 13, 2018 at 6:54 PM, saurabh rathore <rohitsrb2020 at gmail.com>
wrote:

> Dear NCL users,
>
> I used two method to compute vertically integrated moisture flux but none
> of the method is working. Here I am attaching both methods' scripts please
> suggest me with correction that what is the mistake due to my inefficiency
> in NCL. I am also attaching the data files links that I have used. ​​
>
>
>
> I believe I will get the solution.
>
> regards, saurabh
>
> On Tue, Jun 12, 2018 at 2:16 PM, Dennis Shea <shea at ucar.edu> wrote:
>
>>
>> On Mon, Jun 11, 2018 at 8:06 PM, saurabh rathore <rohitsrb2020 at gmail.com>
>> wrote:
>>
>>> Dear NCL users
>>>
>>> I am not much efficient in NCL and trying to compute vertically
>>> integrated Moisture flux divergence. Does anyone ever computed this
>>> quantity I am not able to integrate it vertically and the values I am
>>> getting are 2 order less than the it should be.
>>>
>>> I am using  NCEP/NCAR data of 2.5*2.5 degree resolution for specific
>>> humidity, zonal wind vector and meridional wind vector at 8 pressure levels
>>> which are as follows (300, 400, 500, 600, 700, 850, 925, 1000) i.e.
>>> starting from 300 ending at 1000 hPa
>>>
>>> vertical integration of Moisture flux divergence  =  del . [ (1/g) *
>>> integration from 0 to Ps of (specific humidity * horizontal wind vectors) *
>>> dp ]
>>>
>>> I hope I will get some help regarding this.
>>>
>>> regards, saurabh
>>>
>>> --
>>>
>>>
>>> *REGARDS*
>>>
>>> *Saurabh Rathore*
>>> *Research Scholar (PhD.)*
>>> *Centre For Oceans, Rivers, Atmosphere & Land Science Technology*
>>> *Indian Institute Of Technology, Kharagpur*
>>> *contact :- 91- 8345984434*
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
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>>>
>>>
>>
>
>
> --
>
>
> *REGARDS*
>
> *Saurabh Rathore*
> *Research Scholar (PhD.)*
> *Centre For Oceans, Rivers, Atmosphere & Land Science Technology*
> *Indian Institute Of Technology, Kharagpur*
> *contact :- 91- 8345984434*
>
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