CMIP5 Internal File Metadata

Karl Taylor at PCMDI is leading an effort to define the requirements of netcdf attributes of files depostied in the archive.

In the CMIP3 archive data files had metadata like this example:

title GICC  model output prepared for IPCC Fourth Assessment 2xCO2 equilibrium experiment
institution GICC (Generic International Climate Center, Geneva, Switzerland)
source GICCM1 (2002): atmosphere:  GICAM3 (gicam_0_brnchT_itea_2, T63L32); ocean: MOM (mom3_ver_3.5.2, 2x3L15); sea ice: GISIM4; land: GILSM2.5
contact Rusty Koder (email address)
project_id IPCC Fourth Assessment
table_id Table A1 (25 October 2007)
experiment_id 2xCO2 equilibrium experiment
realization 1
cmor_version 1.3f
Conventions CF-1.0
history Output from archive/giccm_03_std_2xCO2_2256.  At 11:38:30 on 10/09/2008, CMOR rewrote data to comply with CF standards and IPCC Fourth Assessment requirements
references Model described by Koder and Tolkien (J. Geophys. Res., 2001, 576-591).  Also see  2XCO2 simulation described in Dorkey et al. (Clim. Dyn., 2003, 323-357.)
comment Equilibrium reached after 30-year spin-up after which data were output starting with nominal date of January 2030

Additional metadata is expected in CMIP5 of the following form:

model_id short official designation of each model to be used in publications.
forcing list of forcing agents (e.g., volcanic aerosols, ozone, CO2)
associated_files " " (space reserved in case we want to associate another file (like grid files?) with this one.)
creation_data a date and time-stamp of the form: "2008-09-09T19:51:19Z"
realm to designate roughly what component/domain the variable comes from (e.g., land, ocean, biosphere; suggestions for this vocabulary are welcome if they come within the next month or two).
tracking_id " " (space reserved to provide a unique identifier associated with each file, which might be of some use to external databases).

Notes from email with karl:

  1. model_id, will be controlled vocab by CMIP5 team ...
  2. forcing, controlled vocabulary for radiatively active species list ...
  3. realm, to be used to help with file organisation (e.g. directories), vocab to be decided.
  4. associated_files, hope not to use this