[Met_help] [rt.rap.ucar.edu #49744] History for ERA interm data for grid-stat
Paul Oldenburg via RT
met_help at ucar.edu
Wed Oct 12 14:54:08 MDT 2011
----------------------------------------------------------------
Initial Request
----------------------------------------------------------------
Hi,
May I ask if ERA interm data can be directly used by grid-stat? I have
downloaded GRIB1 ERA interm data in two files, one of which contains
only derived U and V. So it seems I need use both. Thank you very much
for your help!
--
Chunhua
----------------------------------------------------------------
Complete Ticket History
----------------------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #49744] ERA interm data for grid-stat
From: Paul Oldenburg
Time: Thu Sep 22 10:28:16 2011
On 09/22/2011 09:54 AM, Chunhua Zhou wrote:
> Hi Paul,
> I got the data from NCAR DSS: http://dss.ucar.edu/datasets/ds627.0/
> I put ERA interm data and also WRF 00h-48h FCST after UPP in a
folder called MET_ERA at scratch
> Thank you very much for your help!
>
On 09/22/2011 09:21 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>
> Thu Sep 22 09:21:29 2011: Request 49744 was acted upon.
> Transaction: Ticket created by chunhua at ucar.edu
> Queue: met_help
> Subject: ERA interm data for grid-stat
> Owner: Nobody
> Requestors: chunhua at ucar.edu
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744 >
>
>
> Hi,
> May I ask if ERA interm data can be directly used by grid-stat? I
have
> downloaded GRIB1 ERA interm data in two files, one of which contains
> only derived U and V. So it seems I need use both. Thank you very
much
> for your help!
------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #49744] ERA interm data for grid-stat
From: Paul Oldenburg
Time: Thu Sep 22 10:56:45 2011
Chunhua,
Please send all email correspondence by replying to the met_help
ticket email, so that we can maintain a record of our
progress for this issue.
Can you please tell me which meteorological fields from your forecast
model data you would like to verify? I assume,
based on your first email, that you are interested in U and V. Are
there other fields that you want to verify?
Also, I do not understand the difference between the forecast model
data files for each lead time that you have made
available to me. For example, what is the difference between
wrfprs_d01.000 and WRFPRS_d01.000? It looks like they
have the exact same set of fields in them. Is one a copy of the
other?
Thanks,
Paul
On 09/22/2011 10:28 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744 >
>
> On 09/22/2011 09:54 AM, Chunhua Zhou wrote:
>> Hi Paul,
>> I got the data from NCAR DSS:
http://dss.ucar.edu/datasets/ds627.0/
>> I put ERA interm data and also WRF 00h-48h FCST after UPP in a
folder called MET_ERA at scratch
>> Thank you very much for your help!
>>
>
> On 09/22/2011 09:21 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>
>> Thu Sep 22 09:21:29 2011: Request 49744 was acted upon.
>> Transaction: Ticket created by chunhua at ucar.edu
>> Queue: met_help
>> Subject: ERA interm data for grid-stat
>> Owner: Nobody
>> Requestors: chunhua at ucar.edu
>> Status: new
>> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744 >
>>
>>
>> Hi,
>> May I ask if ERA interm data can be directly used by grid-stat? I
have
>> downloaded GRIB1 ERA interm data in two files, one of which
contains
>> only derived U and V. So it seems I need use both. Thank you very
much
>> for your help!
>
------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #49744] ERA interm data for grid-stat
From: Chunhua Zhou
Time: Thu Sep 22 11:04:44 2011
Hi Paul,
Sure, I will send emails by replying to met_help. Sorry I forgot to do
that earlier.
For verification, we are interested in mostly UGRD, VGRD, TMP, SPFH
fields on pressure levels: Z02, P1000,
P975-925,P900-850,P825-700,P675-500,P475-400,P375-
300,P250,P200,P150,P100,P70,P50,P30,P20,P10
The files are actually the same. I wasn't sure which filename you
would
use so I copied both.
Thank you very much for your help!!!
Chunhua
On 9/22/11 10:56 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
> Chunhua,
>
> Please send all email correspondence by replying to the met_help
ticket email, so that we can maintain a record of our
> progress for this issue.
>
> Can you please tell me which meteorological fields from your
forecast model data you would like to verify? I assume,
> based on your first email, that you are interested in U and V. Are
there other fields that you want to verify?
>
> Also, I do not understand the difference between the forecast model
data files for each lead time that you have made
> available to me. For example, what is the difference between
wrfprs_d01.000 and WRFPRS_d01.000? It looks like they
> have the exact same set of fields in them. Is one a copy of the
other?
>
> Thanks,
>
> Paul
>
>
> On 09/22/2011 10:28 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>
>> On 09/22/2011 09:54 AM, Chunhua Zhou wrote:
>>> Hi Paul,
>>> I got the data from NCAR DSS:
http://dss.ucar.edu/datasets/ds627.0/
>>> I put ERA interm data and also WRF 00h-48h FCST after UPP in a
folder called MET_ERA at scratch
>>> Thank you very much for your help!
>>>
>> On 09/22/2011 09:21 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>> Thu Sep 22 09:21:29 2011: Request 49744 was acted upon.
>>> Transaction: Ticket created by chunhua at ucar.edu
>>> Queue: met_help
>>> Subject: ERA interm data for grid-stat
>>> Owner: Nobody
>>> Requestors: chunhua at ucar.edu
>>> Status: new
>>> Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>
>>>
>>> Hi,
>>> May I ask if ERA interm data can be directly used by grid-stat? I
have
>>> downloaded GRIB1 ERA interm data in two files, one of which
contains
>>> only derived U and V. So it seems I need use both. Thank you very
much
>>> for your help!
------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #49744] ERA interm data for grid-stat
From: Paul Oldenburg
Time: Thu Sep 22 15:24:54 2011
Chunhua,
There are several issues that we discovered while working with your
data that must be overcome to perform gridded
verification using the data that you made available to me.
1. MET automatically tries to rotate wind direction components to be
earth relative, and since it does not understand
ECMWF grib codes, it cannot perform this step for your observations.
Thus, the rotation of the forecast wind components
must be deactivated by patching the MET instance that you plan to use
for wind verification. Please let us know which
instance of MET you plan to use for your verification, and we can help
you add the patch.
2. You must regrid either your model data or your observation ECMWF
analysis files or both so that they are on the same
grid. One concern that we have is that your obs data is on a coarse
global grid, while your forecast data is a finer
grid. If you regrid your obs data to your forecast grid, you may be
conducting a misleading comparison. We recommend
that you consult Tressa Fowler about how to address this situation.
3. Of all the forecast data that you made available, only the file
wrfprs_d01.000 is valid at the same time as the
observation analysis data, 2011081812. The reason is that the other
forecast files are initialized at 2011081812, but
are future forecasts with lead times of 12, 24, etc. That would make
them valid at 2011081900, 2011081912, etc.
respectively. You must compare that model data to observation
analysis data that is valid at the same time.
4. I built a test case to demonstrate the use of copygb and grid_stat
to generate verification statistics for TMP and
SPFH at 1000 mb. To do so, I regridded your observation analysis data
to the forecast grid (which I raised a concern
about in item #2).
In this test case, the output OBS_VAR column will misleadingly say
MSLET and KX, because of the mis-match in fields
between the NCEP grib codes and ECMWF grib codes that I mentioned
earlier. This shortcoming will be addressed in future
versions of MET.
I put all of the files included in my test, including the output
files, into the tarball at
/scratch/pgoldenb/grid_stat_test.tar.gz. Before you try to run this
test, you must set the variables at the top of the
file gs_test.sh to point to the instances of copygb and grid_stat on
your system. Please let me know if you have any
trouble running this simple test case.
I realize that this is a lot of confusing information. If you have
any other questions or trouble, please let me know.
Thanks,
Paul
On 09/22/2011 11:04 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744 >
>
> Hi Paul,
>
> Sure, I will send emails by replying to met_help. Sorry I forgot to
do
> that earlier.
>
> For verification, we are interested in mostly UGRD, VGRD, TMP, SPFH
> fields on pressure levels: Z02, P1000,
> P975-925,P900-850,P825-700,P675-500,P475-400,P375-
300,P250,P200,P150,P100,P70,P50,P30,P20,P10
>
> The files are actually the same. I wasn't sure which filename you
would
> use so I copied both.
>
> Thank you very much for your help!!!
>
>
>
>
> Chunhua
>
>
> On 9/22/11 10:56 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>> Chunhua,
>>
>> Please send all email correspondence by replying to the met_help
ticket email, so that we can maintain a record of our
>> progress for this issue.
>>
>> Can you please tell me which meteorological fields from your
forecast model data you would like to verify? I assume,
>> based on your first email, that you are interested in U and V. Are
there other fields that you want to verify?
>>
>> Also, I do not understand the difference between the forecast model
data files for each lead time that you have made
>> available to me. For example, what is the difference between
wrfprs_d01.000 and WRFPRS_d01.000? It looks like they
>> have the exact same set of fields in them. Is one a copy of the
other?
>>
>> Thanks,
>>
>> Paul
>>
>>
>> On 09/22/2011 10:28 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>
>>> On 09/22/2011 09:54 AM, Chunhua Zhou wrote:
>>>> Hi Paul,
>>>> I got the data from NCAR DSS:
http://dss.ucar.edu/datasets/ds627.0/
>>>> I put ERA interm data and also WRF 00h-48h FCST after UPP in a
folder called MET_ERA at scratch
>>>> Thank you very much for your help!
>>>>
>>> On 09/22/2011 09:21 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>>> Thu Sep 22 09:21:29 2011: Request 49744 was acted upon.
>>>> Transaction: Ticket created by chunhua at ucar.edu
>>>> Queue: met_help
>>>> Subject: ERA interm data for grid-stat
>>>> Owner: Nobody
>>>> Requestors: chunhua at ucar.edu
>>>> Status: new
>>>> Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>
>>>>
>>>> Hi,
>>>> May I ask if ERA interm data can be directly used by grid-stat? I
have
>>>> downloaded GRIB1 ERA interm data in two files, one of which
contains
>>>> only derived U and V. So it seems I need use both. Thank you very
much
>>>> for your help!
------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #49744] ERA interm data for grid-stat
From: Chunhua Zhou
Time: Thu Sep 22 15:55:26 2011
Hi Paul,
Thank you very much for spending time investigating this.
I have a few questions:
1, Regarding 1 in your email, wind verification is deactivated due to
this rotation issue. Is it possible to use the derived wind field
(ei.oper.an.pl.regn128uv.2010081812) separately for wind only?
2, Still regarding 1 in your email, what do you mean by patching the
MET
instance?
Thank you very much again for your help!
Chunhua
On 9/22/11 3:24 PM, RAL HelpDesk {for Paul Oldenburg} wrote:
> Chunhua,
>
> There are several issues that we discovered while working with your
data that must be overcome to perform gridded
> verification using the data that you made available to me.
>
> 1. MET automatically tries to rotate wind direction components to
be earth relative, and since it does not understand
> ECMWF grib codes, it cannot perform this step for your observations.
Thus, the rotation of the forecast wind components
> must be deactivated by patching the MET instance that you plan to
use for wind verification. Please let us know which
> instance of MET you plan to use for your verification, and we can
help you add the patch.
>
> 2. You must regrid either your model data or your observation ECMWF
analysis files or both so that they are on the same
> grid. One concern that we have is that your obs data is on a coarse
global grid, while your forecast data is a finer
> grid. If you regrid your obs data to your forecast grid, you may be
conducting a misleading comparison. We recommend
> that you consult Tressa Fowler about how to address this situation.
>
> 3. Of all the forecast data that you made available, only the file
wrfprs_d01.000 is valid at the same time as the
> observation analysis data, 2011081812. The reason is that the other
forecast files are initialized at 2011081812, but
> are future forecasts with lead times of 12, 24, etc. That would
make them valid at 2011081900, 2011081912, etc.
> respectively. You must compare that model data to observation
analysis data that is valid at the same time.
>
> 4. I built a test case to demonstrate the use of copygb and
grid_stat to generate verification statistics for TMP and
> SPFH at 1000 mb. To do so, I regridded your observation analysis
data to the forecast grid (which I raised a concern
> about in item #2).
>
> In this test case, the output OBS_VAR column will misleadingly say
MSLET and KX, because of the mis-match in fields
> between the NCEP grib codes and ECMWF grib codes that I mentioned
earlier. This shortcoming will be addressed in future
> versions of MET.
>
> I put all of the files included in my test, including the output
files, into the tarball at
> /scratch/pgoldenb/grid_stat_test.tar.gz. Before you try to run this
test, you must set the variables at the top of the
> file gs_test.sh to point to the instances of copygb and grid_stat on
your system. Please let me know if you have any
> trouble running this simple test case.
>
> I realize that this is a lot of confusing information. If you have
any other questions or trouble, please let me know.
>
> Thanks,
>
> Paul
>
>
> On 09/22/2011 11:04 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>
>> Hi Paul,
>>
>> Sure, I will send emails by replying to met_help. Sorry I forgot to
do
>> that earlier.
>>
>> For verification, we are interested in mostly UGRD, VGRD, TMP, SPFH
>> fields on pressure levels: Z02, P1000,
>> P975-925,P900-850,P825-700,P675-500,P475-400,P375-
300,P250,P200,P150,P100,P70,P50,P30,P20,P10
>>
>> The files are actually the same. I wasn't sure which filename you
would
>> use so I copied both.
>>
>> Thank you very much for your help!!!
>>
>>
>>
>>
>> Chunhua
>>
>>
>> On 9/22/11 10:56 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>> Chunhua,
>>>
>>> Please send all email correspondence by replying to the met_help
ticket email, so that we can maintain a record of our
>>> progress for this issue.
>>>
>>> Can you please tell me which meteorological fields from your
forecast model data you would like to verify? I assume,
>>> based on your first email, that you are interested in U and V.
Are there other fields that you want to verify?
>>>
>>> Also, I do not understand the difference between the forecast
model data files for each lead time that you have made
>>> available to me. For example, what is the difference between
wrfprs_d01.000 and WRFPRS_d01.000? It looks like they
>>> have the exact same set of fields in them. Is one a copy of the
other?
>>>
>>> Thanks,
>>>
>>> Paul
>>>
>>>
>>> On 09/22/2011 10:28 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>
>>>> On 09/22/2011 09:54 AM, Chunhua Zhou wrote:
>>>>> Hi Paul,
>>>>> I got the data from NCAR DSS:
http://dss.ucar.edu/datasets/ds627.0/
>>>>> I put ERA interm data and also WRF 00h-48h FCST after UPP in a
folder called MET_ERA at scratch
>>>>> Thank you very much for your help!
>>>>>
>>>> On 09/22/2011 09:21 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>>>> Thu Sep 22 09:21:29 2011: Request 49744 was acted upon.
>>>>> Transaction: Ticket created by chunhua at ucar.edu
>>>>> Queue: met_help
>>>>> Subject: ERA interm data for grid-stat
>>>>> Owner: Nobody
>>>>> Requestors: chunhua at ucar.edu
>>>>> Status: new
>>>>> Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>>
>>>>>
>>>>> Hi,
>>>>> May I ask if ERA interm data can be directly used by grid-stat?
I have
>>>>> downloaded GRIB1 ERA interm data in two files, one of which
contains
>>>>> only derived U and V. So it seems I need use both. Thank you
very much
>>>>> for your help!
------------------------------------------------
Subject: ERA interm data for grid-stat
From: Paul Oldenburg
Time: Fri Sep 23 08:59:54 2011
Chunhua,
You can verify the U and V components of wind separately using the
ECMWF analysis, but it will require a patch to the
instance of MET that you plan to use. To apply the patch, replace
your copy of
{MET_BASE}/lib/vx_grib_classes/grib_strings.h with the attached
version, clean and rebuild MET. If you have any
trouble, please let me know.
Thanks,
Paul
On 09/22/2011 03:55 PM, RAL HelpDesk {for Chunhua Zhou} wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744 >
>
> Hi Paul,
>
> Thank you very much for spending time investigating this.
>
> I have a few questions:
>
> 1, Regarding 1 in your email, wind verification is deactivated due
to
> this rotation issue. Is it possible to use the derived wind field
> (ei.oper.an.pl.regn128uv.2010081812) separately for wind only?
>
> 2, Still regarding 1 in your email, what do you mean by patching the
MET
> instance?
>
> Thank you very much again for your help!
>
>
> Chunhua
>
>
> On 9/22/11 3:24 PM, RAL HelpDesk {for Paul Oldenburg} wrote:
>> Chunhua,
>>
>> There are several issues that we discovered while working with your
data that must be overcome to perform gridded
>> verification using the data that you made available to me.
>>
>> 1. MET automatically tries to rotate wind direction components to
be earth relative, and since it does not understand
>> ECMWF grib codes, it cannot perform this step for your
observations. Thus, the rotation of the forecast wind components
>> must be deactivated by patching the MET instance that you plan to
use for wind verification. Please let us know which
>> instance of MET you plan to use for your verification, and we can
help you add the patch.
>>
>> 2. You must regrid either your model data or your observation
ECMWF analysis files or both so that they are on the same
>> grid. One concern that we have is that your obs data is on a
coarse global grid, while your forecast data is a finer
>> grid. If you regrid your obs data to your forecast grid, you may
be conducting a misleading comparison. We recommend
>> that you consult Tressa Fowler about how to address this situation.
>>
>> 3. Of all the forecast data that you made available, only the file
wrfprs_d01.000 is valid at the same time as the
>> observation analysis data, 2011081812. The reason is that the
other forecast files are initialized at 2011081812, but
>> are future forecasts with lead times of 12, 24, etc. That would
make them valid at 2011081900, 2011081912, etc.
>> respectively. You must compare that model data to observation
analysis data that is valid at the same time.
>>
>> 4. I built a test case to demonstrate the use of copygb and
grid_stat to generate verification statistics for TMP and
>> SPFH at 1000 mb. To do so, I regridded your observation analysis
data to the forecast grid (which I raised a concern
>> about in item #2).
>>
>> In this test case, the output OBS_VAR column will misleadingly say
MSLET and KX, because of the mis-match in fields
>> between the NCEP grib codes and ECMWF grib codes that I mentioned
earlier. This shortcoming will be addressed in future
>> versions of MET.
>>
>> I put all of the files included in my test, including the output
files, into the tarball at
>> /scratch/pgoldenb/grid_stat_test.tar.gz. Before you try to run
this test, you must set the variables at the top of the
>> file gs_test.sh to point to the instances of copygb and grid_stat
on your system. Please let me know if you have any
>> trouble running this simple test case.
>>
>> I realize that this is a lot of confusing information. If you have
any other questions or trouble, please let me know.
>>
>> Thanks,
>>
>> Paul
>>
>>
>> On 09/22/2011 11:04 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>
>>> Hi Paul,
>>>
>>> Sure, I will send emails by replying to met_help. Sorry I forgot
to do
>>> that earlier.
>>>
>>> For verification, we are interested in mostly UGRD, VGRD, TMP,
SPFH
>>> fields on pressure levels: Z02, P1000,
>>> P975-925,P900-850,P825-700,P675-500,P475-400,P375-
300,P250,P200,P150,P100,P70,P50,P30,P20,P10
>>>
>>> The files are actually the same. I wasn't sure which filename you
would
>>> use so I copied both.
>>>
>>> Thank you very much for your help!!!
>>>
>>>
>>>
>>>
>>> Chunhua
>>>
>>>
>>> On 9/22/11 10:56 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>>> Chunhua,
>>>>
>>>> Please send all email correspondence by replying to the met_help
ticket email, so that we can maintain a record of our
>>>> progress for this issue.
>>>>
>>>> Can you please tell me which meteorological fields from your
forecast model data you would like to verify? I assume,
>>>> based on your first email, that you are interested in U and V.
Are there other fields that you want to verify?
>>>>
>>>> Also, I do not understand the difference between the forecast
model data files for each lead time that you have made
>>>> available to me. For example, what is the difference between
wrfprs_d01.000 and WRFPRS_d01.000? It looks like they
>>>> have the exact same set of fields in them. Is one a copy of the
other?
>>>>
>>>> Thanks,
>>>>
>>>> Paul
>>>>
>>>>
>>>> On 09/22/2011 10:28 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>>>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>>
>>>>> On 09/22/2011 09:54 AM, Chunhua Zhou wrote:
>>>>>> Hi Paul,
>>>>>> I got the data from NCAR DSS:
http://dss.ucar.edu/datasets/ds627.0/
>>>>>> I put ERA interm data and also WRF 00h-48h FCST after UPP in a
folder called MET_ERA at scratch
>>>>>> Thank you very much for your help!
>>>>>>
>>>>> On 09/22/2011 09:21 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>>>>> Thu Sep 22 09:21:29 2011: Request 49744 was acted upon.
>>>>>> Transaction: Ticket created by chunhua at ucar.edu
>>>>>> Queue: met_help
>>>>>> Subject: ERA interm data for grid-stat
>>>>>> Owner: Nobody
>>>>>> Requestors: chunhua at ucar.edu
>>>>>> Status: new
>>>>>> Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>>>
>>>>>>
>>>>>> Hi,
>>>>>> May I ask if ERA interm data can be directly used by grid-stat?
I have
>>>>>> downloaded GRIB1 ERA interm data in two files, one of which
contains
>>>>>> only derived U and V. So it seems I need use both. Thank you
very much
>>>>>> for your help!
------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #49744] ERA interm data for grid-stat
From: Chunhua Zhou
Time: Fri Sep 23 11:29:39 2011
Hi Paul,
Thank you very much ! I will try the patch and see how it works.
Thanks again for your help!
Chunhua
On 9/23/11 8:59 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
> Chunhua,
>
> You can verify the U and V components of wind separately using the
ECMWF analysis, but it will require a patch to the
> instance of MET that you plan to use. To apply the patch, replace
your copy of
> {MET_BASE}/lib/vx_grib_classes/grib_strings.h with the attached
version, clean and rebuild MET. If you have any
> trouble, please let me know.
>
> Thanks,
>
> Paul
>
>
> On 09/22/2011 03:55 PM, RAL HelpDesk {for Chunhua Zhou} wrote:
>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>
>> Hi Paul,
>>
>> Thank you very much for spending time investigating this.
>>
>> I have a few questions:
>>
>> 1, Regarding 1 in your email, wind verification is deactivated due
to
>> this rotation issue. Is it possible to use the derived wind field
>> (ei.oper.an.pl.regn128uv.2010081812) separately for wind only?
>>
>> 2, Still regarding 1 in your email, what do you mean by patching
the MET
>> instance?
>>
>> Thank you very much again for your help!
>>
>>
>> Chunhua
>>
>>
>> On 9/22/11 3:24 PM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>> Chunhua,
>>>
>>> There are several issues that we discovered while working with
your data that must be overcome to perform gridded
>>> verification using the data that you made available to me.
>>>
>>> 1. MET automatically tries to rotate wind direction components to
be earth relative, and since it does not understand
>>> ECMWF grib codes, it cannot perform this step for your
observations. Thus, the rotation of the forecast wind components
>>> must be deactivated by patching the MET instance that you plan to
use for wind verification. Please let us know which
>>> instance of MET you plan to use for your verification, and we can
help you add the patch.
>>>
>>> 2. You must regrid either your model data or your observation
ECMWF analysis files or both so that they are on the same
>>> grid. One concern that we have is that your obs data is on a
coarse global grid, while your forecast data is a finer
>>> grid. If you regrid your obs data to your forecast grid, you may
be conducting a misleading comparison. We recommend
>>> that you consult Tressa Fowler about how to address this
situation.
>>>
>>> 3. Of all the forecast data that you made available, only the
file wrfprs_d01.000 is valid at the same time as the
>>> observation analysis data, 2011081812. The reason is that the
other forecast files are initialized at 2011081812, but
>>> are future forecasts with lead times of 12, 24, etc. That would
make them valid at 2011081900, 2011081912, etc.
>>> respectively. You must compare that model data to observation
analysis data that is valid at the same time.
>>>
>>> 4. I built a test case to demonstrate the use of copygb and
grid_stat to generate verification statistics for TMP and
>>> SPFH at 1000 mb. To do so, I regridded your observation analysis
data to the forecast grid (which I raised a concern
>>> about in item #2).
>>>
>>> In this test case, the output OBS_VAR column will misleadingly say
MSLET and KX, because of the mis-match in fields
>>> between the NCEP grib codes and ECMWF grib codes that I mentioned
earlier. This shortcoming will be addressed in future
>>> versions of MET.
>>>
>>> I put all of the files included in my test, including the output
files, into the tarball at
>>> /scratch/pgoldenb/grid_stat_test.tar.gz. Before you try to run
this test, you must set the variables at the top of the
>>> file gs_test.sh to point to the instances of copygb and grid_stat
on your system. Please let me know if you have any
>>> trouble running this simple test case.
>>>
>>> I realize that this is a lot of confusing information. If you
have any other questions or trouble, please let me know.
>>>
>>> Thanks,
>>>
>>> Paul
>>>
>>>
>>> On 09/22/2011 11:04 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>
>>>> Hi Paul,
>>>>
>>>> Sure, I will send emails by replying to met_help. Sorry I forgot
to do
>>>> that earlier.
>>>>
>>>> For verification, we are interested in mostly UGRD, VGRD, TMP,
SPFH
>>>> fields on pressure levels: Z02, P1000,
>>>> P975-925,P900-850,P825-700,P675-500,P475-400,P375-
300,P250,P200,P150,P100,P70,P50,P30,P20,P10
>>>>
>>>> The files are actually the same. I wasn't sure which filename
you would
>>>> use so I copied both.
>>>>
>>>> Thank you very much for your help!!!
>>>>
>>>>
>>>>
>>>>
>>>> Chunhua
>>>>
>>>>
>>>> On 9/22/11 10:56 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>>>> Chunhua,
>>>>>
>>>>> Please send all email correspondence by replying to the met_help
ticket email, so that we can maintain a record of our
>>>>> progress for this issue.
>>>>>
>>>>> Can you please tell me which meteorological fields from your
forecast model data you would like to verify? I assume,
>>>>> based on your first email, that you are interested in U and V.
Are there other fields that you want to verify?
>>>>>
>>>>> Also, I do not understand the difference between the forecast
model data files for each lead time that you have made
>>>>> available to me. For example, what is the difference between
wrfprs_d01.000 and WRFPRS_d01.000? It looks like they
>>>>> have the exact same set of fields in them. Is one a copy of the
other?
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Paul
>>>>>
>>>>>
>>>>> On 09/22/2011 10:28 AM, RAL HelpDesk {for Paul Oldenburg} wrote:
>>>>>> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>>>
>>>>>> On 09/22/2011 09:54 AM, Chunhua Zhou wrote:
>>>>>>> Hi Paul,
>>>>>>> I got the data from NCAR DSS:
http://dss.ucar.edu/datasets/ds627.0/
>>>>>>> I put ERA interm data and also WRF 00h-48h FCST after UPP in a
folder called MET_ERA at scratch
>>>>>>> Thank you very much for your help!
>>>>>>>
>>>>>> On 09/22/2011 09:21 AM, RAL HelpDesk {for Chunhua Zhou} wrote:
>>>>>>> Thu Sep 22 09:21:29 2011: Request 49744 was acted upon.
>>>>>>> Transaction: Ticket created by chunhua at ucar.edu
>>>>>>> Queue: met_help
>>>>>>> Subject: ERA interm data for grid-stat
>>>>>>> Owner: Nobody
>>>>>>> Requestors: chunhua at ucar.edu
>>>>>>> Status: new
>>>>>>> Ticket<URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=49744>
>>>>>>>
>>>>>>>
>>>>>>> Hi,
>>>>>>> May I ask if ERA interm data can be directly used by grid-
stat? I have
>>>>>>> downloaded GRIB1 ERA interm data in two files, one of which
contains
>>>>>>> only derived U and V. So it seems I need use both. Thank you
very much
>>>>>>> for your help!
>
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