Introduction

This is a brief introduction of the main request parameter syntax.

We recommend that you get familiar with datasets and their availability using http://apps.ecmwf.int/datasets/

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":

retrieve,
 stream=oper,
 levtype=sfc,
 param=165.128/41.128,
 "dataset"=interim,
 step=0,
 grid=0.75/0.75,
 time=00,
 date=2013-09-01/to/2013-09-30,
 type=an,
 class=ei

 #!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
   
server = ECMWFDataServer()
   
server.retrieve({
    'dataset' : "interim",
	'time'    : "00",
	'date'    : "2013-09-01/to/2013-09-30",
    'step'    : "0",
    'type'    : "an",
    'levtype' : "sfc",    
    'param'   : "165.128/41.128",
    'grid'    : "0.75/0.75",
    'target'  : "interim201309.grib"
    })

Keyword

In the Dataset service there is an extra mandatory keyword called dataset which does not appear in normal MARS requests.

Keyword	definition
dataset	See Available Datasets

the other possible MARS keywords are explained in the MARS keywords documentation.