[gradsusr] Get direction of max wind in hourly time serie of a point

[claudiomet]

OK! Good idea !Thank you very much Eric !!!


2013/5/31 Eric Altshuler <ela at cola.iges.org>

> Hello Claudio,
>
> To calculate the prevailing wind direction for a day, you should average
> the hourly u and v components, then find the direction of this average wind
> vector. It's not a good idea to average the hourly wind directions because
> very weak winds would get the same weighting as stronger winds. On the
> other hand, for daily average wind speed, you should average the hourly
> wind speeds.
>
> Best regards,
>
> Eric L. Altshuler
> Research Scientist
> Center for Ocean-Land-Atmosphere Studies
> 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705-3106
> USA
>
> E-mail: ela at cola.iges.org
> Phone: (301) 902-1257
> Fax: (301) 595-9793
>
> ------------------------------
> *From: *"claudiomet" <claudiomet at gmail.com>
> *To: *"GrADS Users Forum" <gradsusr at gradsusr.org>
> *Sent: *Thursday, May 30, 2013 9:47:50 PM
> *Subject: *Re: [gradsusr] Get direction of max wind in hourly time serie
> of a        point
>
>
> Thanks Martin !
>
> I will try the method !
> Concening with the direction no problem, the dataset includes speed in
> degrees
> (It's a WRF output post-processed with ARWpost specifying the wind as u,v
> vectors and speed and direction)
> Thanks again !
>
>
> 2013/5/30 Martin V. Mathew <vmartinmathew at gmail.com>
>
>> Hi
>> I think you can try following two steps to obtain the direction of
>> maximum wind.
>>
>> First you have to find the hour of the day in which have maximum wind
>> speed (use mag and maxloc commands).
>> http://www.iges.org/grads/gadoc/gadocindex.html
>>
>> After identifying the particular hour use trigonometric function *atan2()
>> *to obtain the angle.
>>  http://www.iges.org/grads/gadoc/functionsatt.html
>>
>> Regards
>> Martin
>>
>>
>> On 29 May 2013 21:42, claudiomet <claudiomet at gmail.com> wrote:
>>
>>>  Greetings users.
>>>
>>> I'm writing a script to extract data of a single point in ascii file
>>> (my data set is hourly and I'm extracting daily vaues of max temp, min
>>> temp, max wind, max rel hum, etc... solved).
>>>
>>> But my problem is that I need to obtain the direction of the wind at
>>> the hour of the max wind intensity and the prevailing wind of the day
>>> ¿How can I do this?
>>>
>>> Thanks in advance !
>>>
>>> _______________________________________________
>>> gradsusr mailing list
>>> gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>
>>
>>
>>
>> --
>> Martin V. Mathew
>> Research scholar
>> Centre for Oceans, Rivers, Atmosphere and Land Sciences (CORAL)
>> IIT Kharagpur
>> India.
>>
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>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
>
>
> --
> *Claudio Cortes N.*
> Project Engineer R&D
> Environmental Area
> *MICOMO S.A.*
> *Tel: +56 (2) 22400516
> Cel: +56 (9) 65871064*
> ccortes at micomo.cl
> www.micomo.cl
> Antonio Rabat Sur 6165, Vitacura
>
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>


-- 
*Claudio Cortes N.*
Project Engineer R&D
Environmental Area
*MICOMO S.A.*
*Tel: +56 (2) 22400516
Cel: +56 (9) 65871064*
ccortes at micomo.cl
www.micomo.cl
Antonio Rabat Sur 6165, Vitacura
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