Introduction
This is a brief introduction of the main request parameter syntax.
We recommend that you get familiar with the data and its availability using MARS Catalogue
You can also get the request syntax using " View MARS request " feature.
Syntax
verb, keyword1 = value1, ... = value2, keywordN = valueN
- verb: action to be taken (e.g. retrieve, list, read)
- keyword: a known MARS variable, e.g. type or date
- value: value assigned to the keyword, e.g. Analysis or temperature
Retrieve example from "View MARS request":
MARS request
retrieve, class=ei, stream=oper, expver=1, levtype=sfc, param=165.128/41.128, step=0, grid=0.75/0.75, time=00, date=2013-09-01/to/2013-09-30, area=75/-15/30/42.5, type=an, target="ei_sfc_165_41.grib"
MARS Request explanation
Identification Keywords
https://software.ecmwf.int/wiki/display/UDOC/Identification+keywords
#Specifies the ECMWF classification given to the data class=ei, #Identifies the forecasting system used to generated the data when the same meteorological types are archived stream=oper, #Is the version of the data, 1 is OPERATIONAL expver=1, #Denotes type of level levtype=sfc, #Meteorological parameter param=165.128/41.128, #Determines the type of field to be retrieved: type=an,
Date and Time Keywords
https://software.ecmwf.int/wiki/display/UDOC/Date+and+time+keywords
#Specifies the forecast time step from forecast base time step=0, #Base time time=00, #Specifies the Analysis date, the Forecast base date or Observations date date=2013-09-01/to/2013-09-30,
Post Processing Keywords
https://software.ecmwf.int/wiki/display/UDOC/Post-processing+keywords
#Output grid mesh grid=0.75/0.75, #Area area=75/-15/30/42.5,
Data Storage Keywords
https://software.ecmwf.int/wiki/display/UDOC/Data+storage+keywords
#specifies a Unix file into which data is to be written after retrieval target="ei_sfc_165_41.grib", ##OPTIONAL MARS SERVICE KEYWORD #(Optional) argument to retrieve NetCDF format format=netcdf,
Keywords
You can find all the keyword explanation in our Mars Keywords page.
There is an extra keyword that you can use in Access MARS that does not appear in the MARS Documentation:
Keyword | definition |
---|---|
format | You can add format = netcdf to retrieve the data in NetCDF format. |