[Met_help] [rt.rap.ucar.edu #93965] History for series_analysis question
John Halley Gotway via RT
met_help at ucar.edu
Mon Feb 3 09:29:42 MST 2020
----------------------------------------------------------------
Initial Request
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Hi there,
we're looking at scatterometer winds within series_analysis. Clearly the ascending and descending passes do not cover exactly the same regions every time. When computing stats on the grid, it means that the number of values for each location varies from grid point to grid point.
How is the meaning done? i.e. is the grid-based ob-count used to compute the mean scores?
See below.
[cid:image003.png at 01D5D6C3.C7DFAFF0][cid:image004.png at 01D5D6C3.C7DFAFF0]
Thanks
Marion
--
Dr Marion Mittermaier Manager: Model diagnostics and novel verification
Met Office FitzRoy Road Exeter EX1 3PB United Kingdom
Tel: +44 (0) 330 135 1604
E-mail: marion.mittermaier at metoffice.gov.uk<mailto:marion.mittermaier at metoffice.gov.uk> http://www.metoffice.gov.uk<http://www.metoffice.gov.uk/>
http://www.metoffice.gov.uk/research/people/marion-mittermaier
I am co-chair of the WMO WWRP Joint Working Group on Forecast Verification Research (JWGFVR) http://www.wmo.int/pages/prog/arep/wwrp/new/Forecast_Verification.html
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Complete Ticket History
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Subject: series_analysis question
From: Julie Prestopnik
Time: Wed Jan 29 11:27:47 2020
Hi Marion.
I have assigned this ticket to John, who is likely best able to answer
your
question. He will respond as soon as he is able. Thanks!
Julie
On Wed, Jan 29, 2020 at 9:48 AM marion.mittermaier at metoffice.gov.uk
via RT <
met_help at ucar.edu> wrote:
>
> Wed Jan 29 09:47:45 2020: Request 93965 was acted upon.
> Transaction: Ticket created by marion.mittermaier at metoffice.gov.uk
> Queue: met_help
> Subject: series_analysis question
> Owner: Nobody
> Requestors: marion.mittermaier at metoffice.gov.uk
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=93965 >
>
>
> Hi there,
>
> we're looking at scatterometer winds within series_analysis. Clearly
the
> ascending and descending passes do not cover exactly the same
regions every
> time. When computing stats on the grid, it means that the number of
values
> for each location varies from grid point to grid point.
>
> How is the meaning done? i.e. is the grid-based ob-count used to
compute
> the mean scores?
>
> See below.
>
>
[cid:image003.png at 01D5D6C3.C7DFAFF0][cid:image004.png at 01D5D6C3.C7DFAFF0]
>
>
>
>
> Thanks
> Marion
>
> --
> Dr Marion Mittermaier Manager: Model diagnostics and novel
verification
>
> Met Office FitzRoy Road Exeter EX1 3PB United Kingdom
> Tel: +44 (0) 330 135 1604
> E-mail: marion.mittermaier at metoffice.gov.uk<mailto:
> marion.mittermaier at metoffice.gov.uk> http://www.metoffice.gov.uk<
> http://www.metoffice.gov.uk/>
>
> http://www.metoffice.gov.uk/research/people/marion-mittermaier
>
> I am co-chair of the WMO WWRP Joint Working Group on Forecast
Verification
> Research (JWGFVR)
>
http://www.wmo.int/pages/prog/arep/wwrp/new/Forecast_Verification.html
>
>
>
--
Julie Prestopnik
Software Engineer
National Center for Atmospheric Research
Research Applications Laboratory
Phone: 303.497.8399
Email: jpresto at ucar.edu
My working day may not be your working day. Please do not feel
obliged to
reply to this email outside of your normal working hours.
------------------------------------------------
Subject: series_analysis question
From: John Halley Gotway
Time: Wed Jan 29 17:11:44 2020
Marion,
This issue is addressed by the vld_thresh option in the Series-
Analysis
config file:
//
// Ratio of valid matched pairs to compute statistics for a grid point
//
vld_thresh = 1.0;
Let's say you pass to series-analysis 100 time steps of gridded data.
You're pointing out that some only percentage of those time steps will
contain valid time for each grid point. If you set vld_thresh = 0.01,
then
the tool will write output for a grid point as long as it has at least
one
valid time step. If you set vld_thresh = 1.0 (the default value),
you'll
only get output stats at grid points where all 100 time steps contain
valid
data. So it's up the user to define and configure the required ratio
of
valid data in order to get output stats computed.
When computing means, the denominator is the number of valid matched
pairs. The tool simply ignore bad data values.
For this reason, I always recommend that users configure Series-
Analysis to
write the "TOTAL" statistic... which is just a count of the number of
valid
matched pairs at each grid point.
Hope this helps clarify.
Thanks,
John
On Wed, Jan 29, 2020 at 11:28 AM Julie Prestopnik via RT
<met_help at ucar.edu>
wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=93965 >
>
> Hi Marion.
>
> I have assigned this ticket to John, who is likely best able to
answer your
> question. He will respond as soon as he is able. Thanks!
>
> Julie
>
> On Wed, Jan 29, 2020 at 9:48 AM marion.mittermaier at metoffice.gov.uk
via
> RT <
> met_help at ucar.edu> wrote:
>
> >
> > Wed Jan 29 09:47:45 2020: Request 93965 was acted upon.
> > Transaction: Ticket created by marion.mittermaier at metoffice.gov.uk
> > Queue: met_help
> > Subject: series_analysis question
> > Owner: Nobody
> > Requestors: marion.mittermaier at metoffice.gov.uk
> > Status: new
> > Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=93965 >
> >
> >
> > Hi there,
> >
> > we're looking at scatterometer winds within series_analysis.
Clearly the
> > ascending and descending passes do not cover exactly the same
regions
> every
> > time. When computing stats on the grid, it means that the number
of
> values
> > for each location varies from grid point to grid point.
> >
> > How is the meaning done? i.e. is the grid-based ob-count used to
compute
> > the mean scores?
> >
> > See below.
> >
> >
[cid:image003.png at 01D5D6C3.C7DFAFF0][cid:image004.png at 01D5D6C3.C7DFAFF0]
> >
> >
> >
> >
> > Thanks
> > Marion
> >
> > --
> > Dr Marion Mittermaier Manager: Model diagnostics and novel
> verification
> >
> > Met Office FitzRoy Road Exeter EX1 3PB United Kingdom
> > Tel: +44 (0) 330 135 1604
> > E-mail: marion.mittermaier at metoffice.gov.uk<mailto:
> > marion.mittermaier at metoffice.gov.uk> http://www.metoffice.gov.uk<
> > http://www.metoffice.gov.uk/>
> >
> > http://www.metoffice.gov.uk/research/people/marion-mittermaier
> >
> > I am co-chair of the WMO WWRP Joint Working Group on Forecast
> Verification
> > Research (JWGFVR)
> >
http://www.wmo.int/pages/prog/arep/wwrp/new/Forecast_Verification.html
> >
> >
> >
>
> --
> Julie Prestopnik
> Software Engineer
> National Center for Atmospheric Research
> Research Applications Laboratory
> Phone: 303.497.8399
> Email: jpresto at ucar.edu
>
> My working day may not be your working day. Please do not feel
obliged to
> reply to this email outside of your normal working hours.
>
>
------------------------------------------------
Subject: RE: [rt.rap.ucar.edu #93965] series_analysis question
From: marion.mittermaier at metoffice.gov.uk
Time: Mon Feb 03 06:13:04 2020
Thanks yes that is helpful. I will pass that on.
Marion
-----Original Message-----
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: 30 January 2020 00:12
To: Mittermaier, Marion <marion.mittermaier at metoffice.gov.uk>
Subject: Re: [rt.rap.ucar.edu #93965] series_analysis question
Marion,
This issue is addressed by the vld_thresh option in the Series-
Analysis config file:
//
// Ratio of valid matched pairs to compute statistics for a grid point
// vld_thresh = 1.0;
Let's say you pass to series-analysis 100 time steps of gridded data.
You're pointing out that some only percentage of those time steps will
contain valid time for each grid point. If you set vld_thresh = 0.01,
then the tool will write output for a grid point as long as it has at
least one valid time step. If you set vld_thresh = 1.0 (the default
value), you'll only get output stats at grid points where all 100 time
steps contain valid data. So it's up the user to define and configure
the required ratio of valid data in order to get output stats
computed.
When computing means, the denominator is the number of valid matched
pairs. The tool simply ignore bad data values.
For this reason, I always recommend that users configure Series-
Analysis to write the "TOTAL" statistic... which is just a count of
the number of valid matched pairs at each grid point.
Hope this helps clarify.
Thanks,
John
On Wed, Jan 29, 2020 at 11:28 AM Julie Prestopnik via RT
<met_help at ucar.edu>
wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=93965 >
>
> Hi Marion.
>
> I have assigned this ticket to John, who is likely best able to
answer
> your question. He will respond as soon as he is able. Thanks!
>
> Julie
>
> On Wed, Jan 29, 2020 at 9:48 AM marion.mittermaier at metoffice.gov.uk
> via RT < met_help at ucar.edu> wrote:
>
> >
> > Wed Jan 29 09:47:45 2020: Request 93965 was acted upon.
> > Transaction: Ticket created by marion.mittermaier at metoffice.gov.uk
> > Queue: met_help
> > Subject: series_analysis question
> > Owner: Nobody
> > Requestors: marion.mittermaier at metoffice.gov.uk
> > Status: new
> > Ticket <URL:
> > https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=93965 >
> >
> >
> > Hi there,
> >
> > we're looking at scatterometer winds within series_analysis.
Clearly
> > the ascending and descending passes do not cover exactly the same
> > regions
> every
> > time. When computing stats on the grid, it means that the number
of
> values
> > for each location varies from grid point to grid point.
> >
> > How is the meaning done? i.e. is the grid-based ob-count used to
> > compute the mean scores?
> >
> > See below.
> >
> >
[cid:image003.png at 01D5D6C3.C7DFAFF0][cid:image004.png at 01D5D6C3.C7DFA
> > FF0]
> >
> >
> >
> >
> > Thanks
> > Marion
> >
> > --
> > Dr Marion Mittermaier Manager: Model diagnostics and novel
> verification
> >
> > Met Office FitzRoy Road Exeter EX1 3PB United Kingdom
> > Tel: +44 (0) 330 135 1604
> > E-mail: marion.mittermaier at metoffice.gov.uk<mailto:
> > marion.mittermaier at metoffice.gov.uk> http://www.metoffice.gov.uk<
> > http://www.metoffice.gov.uk/>
> >
> > http://www.metoffice.gov.uk/research/people/marion-mittermaier
> >
> > I am co-chair of the WMO WWRP Joint Working Group on Forecast
> Verification
> > Research (JWGFVR)
> >
http://www.wmo.int/pages/prog/arep/wwrp/new/Forecast_Verification.ht
> > ml
> >
> >
> >
>
> --
> Julie Prestopnik
> Software Engineer
> National Center for Atmospheric Research Research Applications
> Laboratory
> Phone: 303.497.8399
> Email: jpresto at ucar.edu
>
> My working day may not be your working day. Please do not feel
> obliged to reply to this email outside of your normal working hours.
>
>
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