| Table of Contents | ||
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Introduction
This is a brief introduction of the main request parameter syntax.
| Note |
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We recommend that you get familiar with datasets the data and their its availability using http://apps.ecmwf.int/datasets/ MARS Catalogue You can also get the request syntax using " View MARS request " feature. |
Syntax
| Code Block | ||
|---|---|---|
| ||
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":
| Code Block | ||||
|---|---|---|---|---|
| ||||
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
| No Format |
|---|
#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= |
...
| language | py |
|---|---|
| title | Python equivalence |
...
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
| No Format |
|---|
#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
| No Format |
|---|
#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
| No Format |
|---|
#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. |
Keyword
| Keyword | definition |
|---|---|
| dataset | See Dataset section below. |
| Date & Time | |
| time | Base time (00, 06, 12 and 18) Observation time (HHMM or HH:MM: ie 09:30) |
| date | Specifies the Analysis date, the Forecast base date or Observations date. Formats
|
| step | Specifies the forecast time step from forecast base time. Valid values are hours (HH) |
| Fields | |
| type | Determines the type of field to be retrieved: This keyword makes the selection between observations, images or fields, and it determines some of the valid remaining keywords of the request.
|
| levtype | Denotes type of level:
|
| param | Meteorological parameter. (t, temprerature, 130, 30.128, ...) |
| grid | Output grid mesh
|
| Storage | |
| target | specifies a Unix file into which data is to be written after retrieval or manipulation. Path names should always be enclosed in double quotes: target = "analysis.grb" |
...
| Note |
|---|
To access these datasets, you need to agree on the corresponding terms and conditions that can be found under the "Licence" link in the table below. Catalogues can be found in http://apps.ecmwf.int/datasets |