[Go-essp-tech] new expt. to add to CMIP5 and the DRS document
Robert S. Drach
drach1 at llnl.gov
Mon Nov 15 13:09:17 MST 2010
The new experiment has been added to the CMIP5 Controlled Vocabulary
document.
Bob
Karl Taylor wrote:
> 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://BLOCKEDBLOCKEDdods.ipsl.jussieu.fr/cpipsl/ANDRES/
>> <http://BLOCKEDBLOCKED*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://BLOCKEDBLOCKEDwww.BLOCKEDBLOCKEDmpimet.mpg.de/en/wissenschaft/land-im-erdsystem/wechselwirkung-klima-biogeosphaere/landcover-change-emission-data.html
>> <http://BLOCKEDBLOCKED*www.BLOCKEDBLOCKED*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://BLOCKEDBLOCKEDcmip-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://BLOCKEDBLOCKEDcmip-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://BLOCKEDBLOCKEDcmip-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://BLOCKEDBLOCKEDcmip-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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