For an introduction to accessing data via the Polytope Service, please refer to https://github.com/destination-earth-digital-twins/polytope-examples
Below are several examples of key-value pairs which would be used as the "request" within the polytope service.
Surface fields
Retrieve "Sea ice area fraction" (param 31; grid O8000) and "Sea surface temperature" (param 34; grid O8000) at step 0 (0 hours after run start: 2018-11-01, 00:00:00):
request = { 'class' : 'rd', 'date' : '2018-11-01', 'expver' : 'hs3g', 'levtype' : 'sfc', 'param' : '31/34', 'step' : '0', 'stream' : 'oper', 'time' : '00:00:00', 'type' : 'fc' }
Model level fields
Retrieve "Pressure" (param 54; grid TCO7999) for the lowest 10 model levels at step 6 (6 hours after run start: 2018-11-01, 06:00:00):
request = { 'class' : 'rd', 'date' : '2018-11-01', 'expver' : 'hs3g', 'levelist': '128/to/137', 'levtype' : 'ml', 'param' : '54', 'step' : '6', 'stream' : 'oper', 'time' : '00:00:00', 'type' : 'fc' }
Pressure level fields
Retrieve "Specific humidity" (param 133; grid O8000) for the lowest 10 pressure levels at step 24 (24 hours after run start: 2018-11-02, 00:00:00):
request = { 'class' : 'rd', 'date' : '2018-11-01', 'expver' : 'hs3g', 'levelist': '150/200/250/300/400/500/700/850/925/1000', 'levtype' : 'pl', 'param' : '133', 'step' : '24', 'stream' : 'oper', 'time' : '00:00:00', 'type' : 'fc' }
Additional request keywords
Regridding can be used on spectral data only
Please note that the following keywords can be used only on data on the TCO7999 spectral grid. Please see the data catalogue for more information
Other keywords can be used to retrieve parameters on the spectral TCO7999 grid only at a coarsened resolution or for a reduced area. For example:
- To use a coarsened 1° x 1° lat/long grid, use the keyword:
'grid' : '1.0/1.0'
To extract data for a given area, for example Europe, use the keyword:
'area' : '73.5/-27/33/45'
2 Comments
DEA DEA
I am not able to retrieve any of the examples with O8000 data:
Even though I copied the request body from the above examples, I got the following error:
Request 336d6e50-14cf-48bc-9110-69b81f48a79a not found
Matthew Griffith
Hi there,
The above request worked for me using a public account. Please try again.
If you have any further issues please report them through the ECMWF support portal so that we can help you in a more timely manner.
Many thanks!