2. Re-forecasts:
The JMA re-forecasts dataset is a "fixed" dataset which means that the re-forecasts are produced once from a "frozen" version of the model and are used for a number of years to calibrate real-time forecast. The JMA re-forecasts consist of a 5-member ensemble running three times a month from 1981 to 2010. The start dates correspond to 1st / 11th and 21st of each month at 00Z minus 12 hours (28 February instead of 29 February). here is the complete list of re-forecast start dates:
10/20/31 January - 10/20/28 February - 10/20/31 March - 10/20/30 April - 10/20/31 May - 10/20/30 June - 10/20/31 July - 10/20/31 August - 10/20/30 September - 10/20/31 October - 10/20/30 November and 10/20/31 December 1981-2010
The S2S database contains the complete JMA re-forecast dataset.
As for the other models, JMA re-forecasts are archived in the S2S database with 2 date attributes:
- hdate which corresponds to the actual starting date of the re-forecast
- date which correspond tot he ModelVersionDate.Since the JMA re-forecasts are "fixed" re-forecasts this ModelVersiondate is the same for all the re-forecasts and equal to 20140304. This variable will change when a new version of the JMA model for extended-range forecasts will be implemented.
2.1 case 1: 1 param, 1 date
Retrieving one field (10 meter U wind here) for all time steps and for the forecast starting on 10 January 1985
2.1.1 Control forecast
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
"class": "s2",
"dataset": "s2s",
"hdate": "1985-01-10",
"date": "2014-03-04",
"expver": "prod",
"levtype": "sfc",
"origin": "rjtd",
"param": "165",
"step": "12/to/804/by/24",
"stream": "enfh",
"target": "CHANGEME",
"time": "12",
"type": "cf",
})
2.1.2 perturbed forecast
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
"class": "s2",
"dataset": "s2s",
"hdate": "1985-01-10",
"date": "2014-03-04",
"expver": "prod",
"levtype": "sfc",
"origin": "rjtd",
"param": "165",
"step": "12/to/804/by/24",
"stream": "enfh",
"target": "CHANGEME",
"time": "12",
"number": "1/to/4",
"type": "pf",
})
2.2. Re- forecasts used to calibrate a real-time forecast
Retrieving all the fields (10 meter U wind here) for all time steps and used to calibrate the real-time forecast starting on 13 January 2015 (all re-forecasts starting on 10 January and 20 January 1981-2010)
2.2.1 Control forecast
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
"class": "s2",
"dataset": "s2s",
"hdate":
"19810110/19820110/19830110/19840110/19850110/19860110/19870110/19880110/19890110/19900110/19910110/19920110/19930110/19940110/19950110/19960110/19970110/19980110/19990110/20000110/20010110/20020110/20030110/20040110/20050110/20060110/20070110/20080110/20090110/20100110",
"expver": "prod",
"levtype": "sfc",
"origin": "rjtd",
"param": "165",
"step": "12/to/804/by/24",
"stream": "enfh",
"target": "CHANGEME",
"time": "12",
"type": "cf",
" date": "20140304",
})
server.retrieve({
"class": "s2",
"dataset": "s2s",
"hdate":
"19810120/19820120/19830110/19840120/19850120/19860120/19870120/19880120/19890120/19900120/19910120/19920120/19930120/19940120/19950120/19960120/19970120/19980120/19990120/20000120/20010120/20020120/20030120/20040120/20050120/20060120/20070120/20080120/20090120/20100120",
"expver": "prod",
"levtype": "sfc",
"origin": "rjtd",
"param": "165",
"step": "12/to/804/by/24",
"stream": "enfh",
"target": "CHANGEME",
"time": "12",
"type": "cf",
" date": "20140304",
})
2.2.2 Perturbed forecast
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
"class": "s2",
"dataset": "s2s",
"hdate":
"19810110/19820110/19830110/19840110/19850110/19860110/19870110/19880110/19890110/19900110/19910110/19920110/19930110/19940110/19950110/19960110/19970110/19980110/19990110/20000110/20010110/20020110/20030110/20040110/20050110/20060110/20070110/20080110/20090110/20100110",
"expver": "prod",
"levtype": "sfc",
"origin": "rjtd",
"param": "165",
"step": "12/to/804/by/24",
"stream": "enfh",
"target": "CHANGEME",
"time": "12",
"type": "pf",
"number": "1/to/4",
" date": "20140304",
})
server.retrieve({
"class": "s2",
"dataset": "s2s",
"hdate":
"19810120/19820120/19830110/19840120/19850120/19860120/19870120/19880120/19890120/19900120/19910120/19920120/19930120/19940120/19950120/19960120/19970120/19980120/19990120/20000120/20010120/20020120/20030120/20040120/20050120/20060120/20070120/20080120/20090120/20100120",
"expver": "prod",
"levtype": "sfc",
"origin": "rjtd",
"param": "165",
"step": "12/to/804/by/24",
"stream": "enfh",
"target": "CHANGEME",
"time": "12",
"type": "pf",
"number": "1/to/4",
"date": "20140304",
})