[Go-essp-tech] new expt. to add to CMIP5 and the DRS document
Karl Taylor
taylor13 at llnl.gov
Mon Nov 15 11:07:02 MST 2010
Hi Stephen,
Thanks for getting back on this. Note I said "The "Data Reference
Syntax" document and the CMOR tables will be revised shortly to include
these "new" experiments." .... clearly, "shortly" has not yet arrived.
cheers,
Karl
On 11/15/10 2:07 AM, stephen.pascoe at stfc.ac.uk wrote:
>
> Hi Karl,
>
> drslib reads the CMOR MIP tables to find the experiment vocabulary so
> there will be no need to change the code to accommodate a
> historicalExt experiment provided it is defined in the tables.
> However, I notice the latest tables do not include this (downloaded
> today).
>
> Cheers,
>
> Stephen.
>
> ---
>
> Stephen Pascoe +44 (0)1235 445980
>
> Centre of Environmental Data Archival
>
> Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, UK
>
> *From:*go-essp-tech-bounces at ucar.edu
> [mailto:go-essp-tech-bounces at ucar.edu] *On Behalf Of *Karl Taylor
> *Sent:* 13 November 2010 19:33
> *To:* go-essp-tech at ucar.edu
> *Cc:* Charles Doutriaux
> *Subject:* [Go-essp-tech] new expt. to add to CMIP5 and the DRS document
>
> *** nb. Those of you developing software in support of CMIP5 may need
> to modify things to include one more CMIP5 experiment. See below:
>
> Dear all,
>
> At the WGCM meeting in Exeter there was agreement that the
> "historical" runs should be extended from their official ending date
> at the end of 2006 to about year 2012. The concentrations and
> land-use changes specified in these runs will not be the same for all
> groups and may not even be based on true observations (but instead be
> estimated in various ways). Since these runs should not be confused
> with the "historical" runs where everyone uses the same forcing (based
> on observations), the feeling is these short runs (2006-2012) should
> be labeled as a new experiment. I've sent a message to the modeling
> groups describing what they should do. You might want to read items
> 6e and 6f in that message (copied below). To accommodate these new
> runs, we need to add a line to the second table of Appendix 1.1 of the
> DRS document with the following entries:
>
> 7.4 historicalExt historical extension extension of
> the historical simulation (experiment 3.2) through year 2012.
>
> I understand this will require additions to much of the software,
> possibly including CMOR2 tables, ESG publisher?, ESG node software?,
> METAFOR questionnaire, ESG search?, etc.
>
> I apologize for these late changes, but the WGCM thought it important
> to include these extensions of the historical runs so that detection
> attribution studies could be done.
>
> Please pass on this message to anyone who might need to know this
> (beyond those already on the GO-ESSP-tech mail list).
>
> Best regards,
> Karl
>
> ---------------------------
>
> Dear all,
>
> Here are some items that should be of interest to those of you
> participating in CMIP5. Please pass on this information, especially
> to those who are responsible for preparing the model output for the
> CMIP5 archive.
>
> 1. For those of you doing the emissions-driven simulations: Unless
> it's too late, it is recommended that the recently produced gridded
> fossil fuel emissions data from Andres (hosted by IPSL) and the the
> land use data from Houghton (hosted at MPI) should be used for the
> historical simulations. More information should appear soon on the
> CMIP5 website.
>
> These fossil fuel emissions data can be retrieved from:
> http://BLOCKEDdods.ipsl.jussieu.fr/cpipsl/ANDRES/
> <http://BLOCKED*dods.ipsl.jussieu.fr/cpipsl/ANDRES/>
> File name is :
> CMIP5_gridcar_CO2_emissions_fossil_fuel_Andres_1751-2007_monthly_SC_mask11.nc
> It is a monthly dataset, units are gC/m2/s
> Also provided is an ascii file that contains the globally integrated
> emissions for every month.
> CMIP5_gridcar_CO2_emissions_fossil_fuel_Andres_1751-2007_monthly_SC_grid1x1.txt
>
>
> The land use file can be found at MPI:
> http://BLOCKEDwww.BLOCKEDmpimet.mpg.de/en/wissenschaft/land-im-erdsystem/wechselwirkung-klima-biogeosphaere/landcover-change-emission-data.html
> <http://BLOCKED*www.BLOCKED*mpimet.mpg.de/en/wissenschaft/land-im-erdsystem/wechselwirkung-klima-biogeosphaere/landcover-change-emission-data.html>
> File name is: carbon_emissions_landuse_20person.nc
> It is an annual dataset, units are also gC/m2/s
>
> 2. Again for those of you with coupled carbon climate models
> (ESM's): The CMIP5 expts. 5.4 and 5.5 are designed to isolate the
> climate change effects on carbon uptake from the uptake due to CO2
> concentration increases (in the absence of climate change). Originally
> there were two options proposed for these experiments: analyze 1%/yr
> CO2 increase runs or analyze historical+RCP4.5 runs. At the WGCM
> meeting last month and in subsequent discussion, it was decided that
> for groups who have not yet performed these experiments, it would be
> better if they would base these runs on the idealized 1%/yr CO2
> increase (rather than the historical+RCP4.5 simulations). There will,
> of course, also be interest in the historical+RCP4.5 runs, so groups
> who have already done these runs, should contribute them to the archive.
>
> 3. We recently posted a revised document describing the model output
> requirements for CMIP5 (see
> http://BLOCKEDcmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#metadata
> ). (Those of you who have chosen *not* to use CMOR2 to rewrite your
> model output should study this document carefully; those of you using
> CMOR may refer to the CMOR documentation for most of the information
> you need to know. The CMOR documentation has also been recently
> revised with expanded descriptions of what you must supply.) At the
> beginning of the output requirements document there is a link
> directing the user to the bottom of the document where a list of the
> changes that were made can be found. Nearly all the changes were
> simply to improve clarity. Please note, however, that a new global
> attribute is now required for most simulations
> (parent_experiment_rip), which identifies which ensemble member the
> child experiments was spawned from. This information will be
> essential for many CMIP5 studies.
>
> 4. The so-called "data reference syntax" document has also been
> revised. Again, many of the changes should simply make it easier to
> understand. Data providers will be especially interested in the
> official "short names" of the CMIP5 experiments, since these names are
> used in constructing filenames. This document can be obtained through
> the following link:
> http://BLOCKEDcmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#req_format
>
> 5. The latest version of CMOR2 was just released on 12 November
> 2010. The changes made were summarized on an announcement made to
> those of you on the cmor email list. It also includes the latest
> "requested variables" CMOR tables (also posted at
> http://BLOCKEDcmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#req_list
> ), which includes a number of formerly missing "standard names", and
> also some corrections. Please download the latest version of CMOR, the
> CMOR tables and the documentation before continuing to process your data.
>
> 6. At the WGCM meeting there was agreement that it would be useful
> for model evaluation and detection/attribution studies to extend the
> CMIP5 historical runs to near-present (as we have for AMIP), rather
> than ending them in 2005. In fact since the CMIP5 project is ongoing,
> it would be useful to have simulations extended to at least the end of
> 2012 using some estimate of recent and future forcing. There is,
> however, no community-wide accepted observationally-based
> concentration/emissions past 2005. Groups are therefore free to use
> whatever concentrations, solar forcing, SO2 emissions etc. they want
> to use in extending these runs. It is also o.k. for
> detection/attribution studies to simply splice one of the RCP runs to
> the end of the historical simulations. No matter what forcing is
> chosen it is important to consider the following:
>
> a) The groups should take care that there are no substantial
> discontinuities in the forcing in passing from the "past" to the
> "future", defined to be the end of 2005.
>
> b) It is recommended that if an ensemble of "all-forcings" historical
> simulations have been run, then ****each** member of the ensemble
> should be carried to the end of 2012. Thus, a full ensemble of runs
> (through year 2012) would be available for analysis.
>
> c) It is recommended that all historical runs with only a subset of
> forcing (e.g., GHG only, natural forcing only) should also be extended
> through the year 2012.
>
> d) If one of the RCP forcings is used to extend the historical run, it
> may not matter too much which RCP is chosen, and CMIP5 makes no strong
> recommendation. If a modeling group has no preference, they might
> choose the RCP8.5 expt., as at least one group (the Hadley Centre) has
> made this choice already.
>
> e) For all-forcing (anthro + natural) historical runs, the extended
> portions of these runs should be treated as a new runs spawned from
> the parent historical runs at the end of year 2005. If this run is
> forced by an RCP that extends at least to the end of the 21st century,
> then nothing special needs to be done. If, however, some other
> forcing is used or if the run is an RCP run that is truncated after a
> few years (say ending in 2012), then the run should be considered a
> "historical extension" experiment with its output placed in a
> directory named historicalExt. The "forcing" attribute (a netCDF
> global attribute) should describe what forcing is used to extend the
> run, and this information will also need to be recorded when entering
> information about the run in the METAFOR questionnaire. Placing the
> extended portion of the historical runs in a separate place will help
> guard against users assuming that these runs are necessarily based on
> historically-measured concentrations, land-use changes, solar forcing,
> etc. For these historicalExt experiments, the ensemble member
> (designated by the "rip" value appearing in the filename and recorded
> as netCDF global attributes) will be identical to the historical run
> it extends. Also for the runs, the identifying netCDF global
> attributes should be defined as follows: experiment="historical
> extension" and experiment_id="historicalExt". The "Data Reference
> Syntax" document and the CMOR tables will be revised shortly to
> include these "new" experiments.
>
> f) If one chooses to do historical runs with only a subset of forcing
> (e.g., GHG only, natural forcing only, single-forcing experiments,
> etc.), then all the data for the complete historical period and in the
> extended portion (from 2006-2012) would be kept together, no matter
> what forcing was used (in the historicalNat, historicalGHG, or
> historicalMisc directories). (In these clearly "unrealistic" cases,
> naive users will be less likely to access the output and possibly
> misuse it.)
>
> 7. For your information, We've posted (see
> http://BLOCKEDcmip-pcmdi.llnl.gov/cmip5/terms.html?submenuheader=3 )
> the latest (and final) version of the the two different terms of use
> governing the CMIP5 model output. It looks like about half the groups
> plan to release their data for "unrestricted" use and half for
> "non-commercial educational and research purposes" only.
>
> Carry on!
>
> Best regards,
> your faithful CMIP5 comrades (Karl's lame attempt to try to develop a
> little esprit de corps here),
> Karl and Ron
>
>
> --
> Scanned by iCritical.
>
>
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