[Met_help] [rt.rap.ucar.edu #67410] History for Wind direction statistics by station

John Halley Gotway via RT met_help at ucar.edu
Mon Jun 2 11:13:52 MDT 2014


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  Initial Request
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Dear MET help team

hope you are doing fine at your end

I am Victor Almanza and am using  MET to evaluate WRF model runs.

I would like to ask for your help with the following questions:

1)  is it possible to obtain aggregated statistics of surface wind direction (10 m) by station with "stat_analysis".

I am interested in the model performance for wind direction at several monitoring stations. Specifically, to obtain aggregated "AGGR_WDIR" lines at each station over a defined time period (day,week, month) similar to when running for MPR lines (Temp for instance) with the "-by" flag.

I don't have it clear if this is possible, or if am overlooking something obvious.  If so, could you provide please any hints/advice on that ?


2) I am interested in obtaining the BIAS of wind direction.

 Is it possible to do it with MET ?.. if not, could you provide directions of which  subroutines to look at in the code ?


Thank you in advance for your time
Best

Victor

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  Complete Ticket History
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Subject: Re: [rt.rap.ucar.edu #67410] Wind direction statistics by station
From: John Halley Gotway
Time: Mon Jun 02 10:23:40 2014

Victor,

Unfortunately, Stat-Analysis does not currently have the capability of
computing wind direction errors from the MPR line type.

It can only compute wind direction errors from the VL1L2 line type.
There is a way to do the analysis you're after, but it's a bit clumsy.
When you run Point-Stat, you'd have to define each of the
stations in which you're interested as a separate masking region.
Then you'd end up with 1 VL1L2 line type for each station.  It'd
basically just have 1 point in it.  The name of the masking region
would just be the name of the station.  Then you could run the
following type of Stat-Analysis job:
    -job aggregate_stat -line_type VL1L2 -out_line_type WDIR -by
VX_MASK

That'd compute wind direction error for each unique entry in the
VX_MASK column - which would be the stations for which you've computed
VL1L2 output lines.

That would do it, but I realize that this is clunky to have to define
separate masking regions for each station of interest.

It occurs to me that we probably could create a new Stat-Analysis job
type that would convert MPR lines to wind direction errors.  It would
search for pairs of UGRD and VGRD matched pairs and use them
to compute wind direction errors.  I'll document this idea as an area
for future development, but for now you're stuck with the VL1L2 to
WDIR conversion.

Hope that helps clarify.

As for your question about bias, here's the info I received from our
resident statistician...

The aggregated wdir mean error is  the bias. It will be most
meaningful when conditional biases do not cancel each other out, so
small areas (or single stations) with similar prevailing wind
directions (e.g. don't mix seasons, day and night, etc. if they are
very different).

Thanks,
John

On 05/30/2014 08:03 PM, Victor Almanza via RT wrote:
>
> Fri May 30 20:03:10 2014: Request 67410 was acted upon.
> Transaction: Ticket created by halmanset at yahoo.com
>         Queue: met_help
>       Subject: Wind direction statistics by station
>         Owner: Nobody
>    Requestors: halmanset at yahoo.com
>        Status: new
>   Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=67410 >
>
>
> Dear MET help team
>
> hope you are doing fine at your end
>
> I am Victor Almanza and am using  MET to evaluate WRF model runs.
>
> I would like to ask for your help with the following questions:
>
> 1)  is it possible to obtain aggregated statistics of surface wind
direction (10 m) by station with "stat_analysis".
>
> I am interested in the model performance for wind direction at
several monitoring stations. Specifically, to obtain aggregated
"AGGR_WDIR" lines at each station over a defined time period
(day,week, month) similar to when running for MPR lines (Temp for
instance) with the "-by" flag.
>
> I don't have it clear if this is possible, or if am overlooking
something obvious.  If so, could you provide please any hints/advice
on that ?
>
>
> 2) I am interested in obtaining the BIAS of wind direction.
>
>   Is it possible to do it with MET ?.. if not, could you provide
directions of which  subroutines to look at in the code ?
>
>
> Thank you in advance for your time
> Best
>
> Victor
>

------------------------------------------------
Subject: Wind direction statistics by station
From: Victor Almanza
Time: Mon Jun 02 11:13:18 2014

Dear John,

It did clarify my questions.
That hint is helpful indeed. 

I have a small region in complex terrain with rather few stations. I
think this helps in evaluating WRF results by station (T, Wind Speed,
RH, Wind Direction). 

Thank you very much for your time

Best !

Victor


________________________________
 De: John Halley Gotway via RT <met_help at ucar.edu>
Para: halmanset at yahoo.com
Enviado: Lunes, 2 de junio, 2014 9:23 A.M.
Asunto: Re: [rt.rap.ucar.edu #67410] Wind direction statistics by
station


Victor,

Unfortunately, Stat-Analysis does not currently have the capability of
computing wind direction errors from the MPR line type.

It can only compute wind direction errors from the VL1L2 line type. 
There is a way to do the analysis you're after, but it's a bit
clumsy.  When you run Point-Stat, you'd have to define each of the
stations in which you're interested as a separate masking region. 
Then you'd end up with 1 VL1L2 line type for each station.  It'd
basically just have 1 point in it.  The name of the masking region
would just be the name of the station.  Then you could run the
following type of Stat-Analysis job:
    -job aggregate_stat -line_type VL1L2 -out_line_type WDIR -by
VX_MASK

That'd compute wind direction error for each unique entry in the
VX_MASK column - which would be the stations for which you've computed
VL1L2 output lines.

That would do it, but I realize that this is clunky to have to define
separate masking regions for each station of interest.

It occurs to me that we probably could create a new Stat-Analysis job
type that would convert MPR lines to wind direction errors.  It would
search for pairs of UGRD and VGRD matched pairs and use them
to compute wind direction errors.  I'll document this idea as an area
for future development, but for now you're stuck with the VL1L2 to
WDIR conversion.

Hope that helps clarify.

As for your question about bias, here's the info I received from our
resident statistician...

The aggregated wdir mean error is  the bias. It will be most
meaningful when conditional biases do not cancel each other out, so
small areas (or single stations) with similar prevailing wind
directions (e.g. don't mix seasons, day and night, etc. if they are
very different).

Thanks,
John

On 05/30/2014 08:03 PM, Victor Almanza via RT wrote:
>
> Fri May 30 20:03:10 2014: Request 67410 was acted upon.
> Transaction: Ticket created by halmanset at yahoo.com
>         Queue: met_help
>       Subject: Wind direction statistics by station
>         Owner: Nobody
>    Requestors: halmanset at yahoo.com
>        Status: new
>   Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=67410 >
>
>
> Dear MET help team
>
> hope you are doing fine at your end
>
> I am Victor Almanza and am using  MET to evaluate WRF model runs.
>
> I would like to ask for your help with the following questions:
>
> 1)  is it possible to obtain aggregated statistics of surface wind
direction (10 m) by station with "stat_analysis".
>
> I am interested in the model performance for wind direction at
several monitoring stations. Specifically, to obtain aggregated
"AGGR_WDIR" lines at each station over a defined time period
(day,week, month) similar to when running for MPR lines (Temp for
instance) with the "-by" flag.
>
> I don't have it clear if this is possible, or if am overlooking
something obvious.  If so, could you provide please any hints/advice
on that ?
>
>
> 2) I am interested in obtaining the BIAS of wind direction.
>
>   Is it possible to do it with MET ?.. if not, could you provide
directions of which  subroutines to look at in the code ?
>
>
> Thank you in advance for your time
> Best
>
> Victor
>

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