Re: [ferret_users] walker circulation

[Ryo Furue <furue@xxxxxxxxxx>]

On Mon, Aug 1, 2016 at 1:44 PM, ektaraful . <ektarak@xxxxxxxxx> wrote:
> In literature omega is multiplied by -5*abs(average of U/average of omega),
> so which is most correct way?
>
> regards.
>
> On Thu, Jul 28, 2016 at 3:31 AM, saurabh rathore <rohitsrb2020@xxxxxxxxx>
> wrote:
>>
>> Thanks Ryo, for your suggestion i never thought it in this way, for me the
>> vertical wind vectors are seems to be very small so for qualitative purpose
>> i magnified it by a factor of 100.
>>
>> but i really appreciated your suggestion to work it on for my analysis
>> also.
>>
>> regards, Saurabh
>>
>> On Thu, Jul 28, 2016 at 12:45 PM, Ryo Furue <furue@xxxxxxxxxx> wrote:
>>>
>>> Hi Saurabh and  Ektaraful and Ferret users,
>>>
>>> > vector . . .  uu1[y=-10:10@ave], -100*ww1[y=-10:10@ave]
>>>
>>> I've been bothered by this kind of factor.  In this case, it's "100".
>>>
>>> You think vertical velocity is too small and so you want to magnify
>>> it.  But what factor is optimal?
>>>
>>> I think that's the wrong question.  In the x-z plane, the arrow has to
>>> be parallel to the local streamline (the local trajectory of the fluid
>>> parcel).  Assuming that you use consistent units between the velocity
>>> components and the axes, Ferret gives you the "correct" plot with
>>>
>>>    vector/ASPECT  u,w
>>>
>>> If the horizontal axis is kilometers or degrees and u is in m/s, for
>>> example, you have to scale u appropriately (not tested).
>>>
>>> The same principle should apply to pressure coordinates.  If the
>>> "vertical" velocity is in the units of pressure/time, ASPECT will give
>>> you "correct" vectors in that the fluid parcel moves parallel to the
>>> arrows in the x-p space.  Likewise, if the vertical axis is log(p),
>>> then "velocity" log(p)/time should be the appropriate "vertical"
>>> velocity.  But I haven't tested these latter ideas.
>>>
>>> Regards,
>>>
>>> Ryo
>>
>>
>>
>>
>> --
>>
>>
>> REGARDS
>>
>> Saurabh Rathore
>> Research Scholar (PhD.)
>> Centre For Oceans, Rivers, Atmosphere & Land Science Technology
>> Indian Institute Of Technology, Kharagpur
>> contact :- 91- 8345984434
>
>