PMIP 2 Database OPeNDAP Access


 

Server status

The status of the OPeNDAP server is automatically checked once an hour, and a mail is sent to the administrators if there is a problem. You can also report problems by sending a mail to the DB administrator.

OPeNDAP server: the server is online!
(Last check time = 2014 08 04 10:30)

IMPORTANT notes

If you don't know NetCDF, Linux/UNIX, etc...

If you are not familiar with Linux and do not know the NetCDF file format, you can easily install the Panoply program to look at the data. You should of course first check if you favorite data plotting and analysis software can read NetCDF files (maybe through an extension that you need to download). The steps below should help you getting started with Panoply:

Using the server to transfer full NetCDF files

Just point your favorite web browser to

    http://www-lscedods.cea.fr/pmip2_dbextDO_NOT_INDEX/

    Note: remove the DO_NOT_INDEX string at the end of the URL! We have added it on purpose to avoid web indexing engines from downloading/indexing all the files in the DB...

Navigate down the directory hierarchy to the file you want to retrieve (you may want to look at the Variables and DB structure pages), click on it, and save it where you want on your local machine. This is pretty fast (if you have a good network connection), but you have to select each file by hand!

There are some ftp clients that will make transferring files like this easier (if they can handle transfer over http...). You can use for instance the linux lftp ftp client:

    lftp http://www-lscedods.cea.fr/pmip2_dbextDO_NOT_INDEX/

You may also want to check what files are available, before travelling (down) the database.

Using the server to access the files' meta-data

Just point your favorite web browser to

    http://www-lscedods.cea.fr/cgi-bin/nph-dods/pmip2_dbextDO_NOT_INDEX/

    Note: remove the DO_NOT_INDEX string at the end of the URL! We have added it on purpose to avoid web indexing engines from downloading/indexing all the files in the DB...

Navigate down the directory hierarchy to the file you are interested in, click on it, and study the displayed information. When you click on file.nc in the displayed list of files, it will open a page with the following URL (notice that the URL ends with .nc.html):

    http://www-lscedods.cea.fr/cgi-bin/nph-dods/pmip2_dbext/<path_in_the_DB>/file.nc.html

Using the server to access (part of) a variable

This is particularly useful if the programs you use have been linked with the OPeNDAP NetCDF library. You can then access remote files in the PMIP2 database by opening the following kind of file name:

    http://www-lscedods.cea.fr/cgi-bin/nph-dods/pmip2_dbextDO_NOT_INDEX/<path_in_the_DB>/file.nc

Summary

If you are interested in the content of path/file.nc, where path is the full path to the data file file.nc

  1. http://www-lscedods.cea.fr/                 pmip2_dbext/<path>/file.nc
  2. http://www-lscedods.cea.fr/cgi-bin/nph-dods/pmip2_dbext/<path>/file.nc.html
  3. http://www-lscedods.cea.fr/cgi-bin/nph-dods/pmip2_dbext/<path>/file.nc
  1. Download the complete data file.
  2. Display information about the file in a web browser.
  3. Access the content of the file with a client compiled with the OPeNDAP NetCDF library.

Example, using python/CDAT

Notes

jypeter ... >python
Python 2.4.3 (#1, Nov 29 2007, 15:23:25) 
[GCC 4.1.2 20070626 (Red Hat 4.1.2-14)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import cdms, genutil
>>> f = cdms.open('http://www-lscedods.cea.fr/cgi-bin/nph-dods/pmip2_dbext/pmip2
_21k_oa/atm/fixed/orog/orog_A_FX_pmip2_21k_oa_IPSL-CM4-V1-MR.nc')
>>> v = f('orog')
>>> f.close()
>>> genutil.minmax(v)
(0.0, 5136.7060546875)
>>> v.shape
(72, 96)
>>> v.info()
*** Description of Slab orog ***
id: orog
shape: (72, 96)
filename: 
missing_value: [  1.00000002e+20,]
comments: 
grid_name: 
grid_type: generic
time_statistic: 
long_name: Surface Altitude
units: m
original_name: ZMEA
standard_name: surface_altitude
original_units: m
history:  At   18:17:10 on 11/04/2005: CMOR altered the data in the following wa
ys:  Cyclical dimension was output starting at a different lon;
Grid has Python id 0x2b699e7d7a28.
Gridtype: generic
Grid shape: (72, 96)
Order: yx
** Dimension 1 **
   id: lat
   Designated a latitude axis.
   units:  degrees_north
   Length: 72
   First:  -90.0
   Last:   90.0
   Other axis attributes:
      long_name: latitude
      standard_name: latitude
      original_units: degrees_north
      axis: Y
   Python id:  0x2b699e7dd1b8
** Dimension 2 **
   id: lon
   Designated a longitude axis.
   units:  degrees_east
   Length: 96
   First:  0.0
   Last:   356.25
   Other axis attributes:
      long_name: longitude
      standard_name: longitude
      original_units: degrees_east
      axis: X
      modulo: 360.0
      topology: circular
   Python id:  0x2b699e7dd518
*** End of description for orog ***


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