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Hi everybody,<br>
<br>
Several groups have expressed interest to publish downscaled climate
datasets on ESGF. A standardized solution to publishing (directory
structure elements) would contribute to the prompt identification of
datasets. To discuss needs and options for directory structure
elements we had an initial teleconference about a month ago. With
this email we are expanding our reach to other groups, such as the
go-essp group, in order to have a wider discussion of these
elements.<br>
<br>
As agreed during our first teleconference, Aparna and Galia worked
on a proposal for a Directory Structure for publishing downscaled
datasets on ESGF. We would like to focus our next teleconference on
discussing this proposal. Below please find a doodle poll for a
potential next teleconference.<br>
<br>
<pre wrap=""><a class="moz-txt-link-freetext" href="http://doodle.com/hrwthqs2g5pgsyv6">http://doodle.com/hrwthqs2g5pgsyv6</a></pre>
<br>
**********************************************************************<br>
Details of each element of the proposed directory structure:<br>
<br>
Proposed elements -<br>
/projectID/<font color="#3333ff">sub-project</font>/product/institution/<b>predictorModel/experimentID/frequency/realm/MIPtable/Pred</b><b><br>
</b><b>ictor_experiment_rip/predictorversion</b>/<i>downscalingMethod/predictand
(variableName)/region</i>/<i>DownscaledDataversion</i>/file_name.nc<br>
<br>
Example:<br>
<br>
/ncpp2013/<font color="#3333ff">perfectModel</font>/downscaled/NOAA-GFDL/<b>GFDL-HIRAM-C360-coarsened/amip/day/atmos/day/r1i1p1/v20121024</b>/<i>GFDL-ARRMv1/tasmax/US48/v20120227</i>/tasmax_day_amip_r1i1p1_downscaled_US48_GFDLARRMv1_19790101-19831231.nc<br>
<br>
The new element <font color="#3333ff">sub-project </font>(in blue
above) gives the opportunity to indicate to users that in the one
case the method was trained on observations (standard setting), and
in the other on model that was considered to be the truth (perfect
model setting);<br>
The options there could be: PerfectModel or Standard - where
possibly there could be a different name instead of 'standard' for
the standard downscaling setting.<br>
<br>
<p>For NASA datasets some of the directories could be: <br>
</p>
project = NEX<br>
product = downscaled<br>
institution = NASA-Ames<br>
predictorModel - original model value<br>
experimentID = historical<br>
frequency = mon<br>
realm = atmos<br>
Predictor_experiment_rip - original model value<br>
variable = precipitation or temperature<br>
region = CONUS<br>
<br>
DownscalingMethod will also be included as a directory to allow for
search on method.<br>
<br>
**********************<br>
There are a set of sub-directories that refer to the <u>PredictorModel</u>
- presented in bold - <b>/predictorModel/experimentID/frequency/realm/MIPtable/Pred</b><b><br>
</b><b>ictor_experiment_rip/predictorversion</b><br>
<br>
Where: <br>
<ul>
<li>predictor model - is the specific GCM which is the source of
the predictor data set - GFDL-HIRAM-C360-coarsened - in the
above example</li>
<li>experimentID - the specific experiment - amip in this case</li>
<li>frequency - refers to the temporal scale of the predictor
fields - daily</li>
<li>realm - the realm of the predictors - in this case
atmos(phere)</li>
<li>MIPtable - name of the model intercomparison table - daily in
this example, could be amon - for atm monthly data;</li>
<li>Predictor-Experiment-rip - follows the standard notation from
CMIP5</li>
<li>version - the version date of the global model that provided
the predictor dataset</li>
</ul>
<p>The elements above follow quite closely the structure for CMIP5
model output directory elements.<br>
</p>
There is a set of sub-directories that refer to the Downscaling
method - presented in italics - <br>
<i><i>downscalingMethod/predictand (variableName)/region</i>/<i>DownscaledDataversion<br>
</i> <br>
</i>Where:<br>
<ul>
<li>downscalingMethod - is the downscaling method abbreviation -
in this case GFDL-ARRMv1 - the GFDL in the name indicates that
this is a setting applied by GFDL where there were two sets of
predictors, based on the ARRM method of K.Hayhoe; also v.1
indicates which version of the ARRM method was used (the
original version) - more details about the method are given in
the global attributes of the file;</li>
<li>Predictand (variableName) - the specific predictand variable
that was downscaled; tasmax in this case;<br>
</li>
<li>region - indicates that the method was applied to the US48</li>
<li>DownscaledDataversion - the version of the downscaled dataset<br>
</li>
</ul>
<p><b>For the purposes of standardization there are two directions
to consider:</b> <br>
</p>
<p>1) One is to have<b> one standard directory</b> structure that
will be used by all - for example, following the example of GFDL
to have the details of the predictor model first and then the
downscaling method details:</p>
<ul>
<li>ProjectID - sub-project - product - Institution - Predictor
dataset details - Downscaling method details - Filename</li>
</ul>
<p> Having a standardized approach would help any automated
service/web service to detect the directory path for a particular
dataset. </p>
<p>2) During our last teleconference there was a proposal to follow
the downscaling practice and describe the downscaling method first
and then the predictor model. This leads to <b>two paths</b>:</p>
<p> • ProjectID - <u><font color="#3333ff">Standard or
Perfect Model sub-project facet</font></u><font
color="#3333ff"> </font>- product - Institution - then see
below:<br>
- (if Perfect model setting) Predictor dataset
details - Downscaling method details, <br>
- (if Standard setting) - Downscaling method
details - Predictor dataset details<br>
</p>
<p><br>
The NCPP Core team accepts that it may be reasonable to have a
directory structure - where the method description is first; and
another directory structure - where the predictor description is
first and then the methods that are applied are described; <b>NCPP
will support either approach</b> (one overall directory
structure, or two separate pathways) and if the second approach is
chosen (with two different sub-directory sequences) - we would
like to promote and to support the standardization of these
different directory pathways - meaning - we will support two
standardized directory structures to accommodate two common
practices.<br>
</p>
<p><br>
</p>
******************<br>
<font color="#009900">Additional details<font color="#000000">: </font></font><br>
<br>
<b>Variable level attributes-</b><br>
The published dataset should also conform to CF-standards. <br>
eg-<br>
<br>
tasmax:long_name = "Downscaled Daily Maximum
Near-Surface Air Temperature"
;
<br>
tasmax:units = "K"
;
<br>
tasmax:missing_value = 1.e+20f
;
<br>
tasmax:_FillValue = 1.e+20f
;
<br>
tasmax:standard_name = "air_temperature"
;
<br>
tasmax:original_units = "K"
;
<br>
<b> tasmax:downscaling_method: GFDL-ARRMv1</b><br>
<br>
<b>Global attributes- </b>listing a few here, several CMIP-style
attributes will be inherited. <br>
<br>
"predictorModel" will replace "model_id"<br>
For the 'downscaling model', as agreed with Luca on the call it
would be 'downscalingMethod' <br>
<br>
:Conventions = "CF-1.4" ;<br>
:references = "info about model, training datasets
etc will be provided here"<br>
:info = "additional info about the downscaling
method" <br>
:creation_date = "2011-08-19T21:57:06Z" ;<br>
:institution = "NOAA GFDL(201 Forrestal Rd,
Princeton, NJ, 08540)" ;<br>
:history = "info on file processing. Eg" processed
by toolX." ;<br>
:projectID = ncpp2013<br>
:subprojectID = perfectModel<br>
:product = downscaled<br>
:institution = NOAA-GFDL<br>
:predictorModel = GFDL-HIRAM-C360-coarsened<br>
:experimentID = amip<br>
:frequency = day<br>
:modeling_realm = atmos<br>
:Predictor_experiment_rip = r1i1p1<br>
:region = US48<br>
:table_id = day<br>
:version = v20120227<br>
:downscalingMethod = GFDL-ARRMv1<br>
**************************************************<br>
<br>
Best regards,<br>
Galia and Aparna<br>
<br>
<pre class="moz-signature" cols="72">--
Galia Guentchev, PhD
Project Scientist
National CLimate
Predictions and
Projections
Platform (NCPP)
NCAR RAL CSAP
FL2 3103
3450 Mitchell Lane
Boulder, CO, 80301
phone: 303 497 2743 </pre>
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