ECMWF实时开放数据官方说明、下载

• Useful Links & Support
  • Support level for this dataset
• About this dataset
  • File format
  • File-naming convention
  • Attribution
• Accessing this dataset
  • Locations
  • Examples using wget for products based on the Atmospheric Model high-resolution (HRES) forecasts
  • Examples using wget for products based on the Wave Model high-resolution (HRES-WAM) forecasts
  • Examples using wget for products based on the Atmospheric Model ensemble (ENS) forecasts
  • Examples using wget for products based on the Wave Model ensemble (ENS-WAM) forecasts
  • Download a single field with wget
  • Index files
  • Differences between MARS language and file naming convention

About this dataset

ECMWF Open Data (real-time) is provided with an open licence (CC-BY-4.0). Data accessed via the public ECMWF web site are free of charge.

This page describes how the data are organised and how they can be downloaded.

A Python package called ecmwf-opendata is available from PyPi that greatly facilitates the access to this dataset. In addition, a series of Jupyter Notebooks have been developed to demonstrate the use of this package.

Availability

The data are released 1 hour after the real-time dissemination schedule.

File format

The files are in GRIB edition 2 format, except for trajectories which are in BUFR edition 4 format. We recommend using ecCodes version 2.24.2 or newer to manipulate the GRIB and BUFR files.

File-naming convention

The files are provided with the following naming convention:

[ROOT]/[yyyymmdd]/[HH]z/[resol]/[stream]/[yyyymmdd][HH]0000-[step][U]-[stream]-[type].[format]

where:

• [ROOT] is the top-level URL of one of the sites hosting the data. See the Locations below for possible values.
• [yyyymmdd] is the reference date of the forecasts (base date).
• [HH] is the reference time of the forecasts. Values are 00, 06 , 12 and 18.
• [resol] is the horizontal resolution of the data. This is currently set to 0p4-beta and will be changed to 0p4 when the beta-testing period is over.
• [stream] is the forecasting system that produces the data. Values are:
  • oper - high-resolution forecast, atmospheric fields
  • enfo - ensemble forecast, atmospheric fields
  • waef - ensemble forecast, ocean wave fields,
  • scda - short cut-off high-resolution forecast, atmospheric fields (also known as "high-frequency products")
  • scwv - short cut-off high-resolution forecast, ocean wave fields (also known as "high-frequency products") and
  • mmsf - multi-model seasonal forecasts fields from the ECMWF model only.
• [step] is the forecast time step expressed in units U
• [U] is the unit used for the time step. Values are h for hours and m for month. The latter is only valid for seasonal forecasts (mmsf).
• [type] is once of fc (forecast), ef (ensemble forecast), ep (ensemble probabilities) or tf (trajectory forecast for tropical cyclone tracks).
• [format] is grib2 for all fields, and bufr for the trajectories.

The valid combinations of the above are:

format=bufr, type=tf 
   HH=00/12 
      stream=enfo/oper, step=240h 
   HH=06/18 
      stream=enfo, step=144h 
      stream=scda, step=90h 
format=grib2 
   HH=00/12 
      stream=enfo/waef 
        type=ef, step=0h to 144h by 3h, 144h to 360h by 6h 
        type=ep, step=240h/360h 
      stream=oper, wave 
        type=fc, step=0h to 144h by 3h, 144h to 240h by 6h 
   HH=06/18 
      stream=enfo/waef 
        type=ef, step=0h to 144h by 3h 
      stream= scda /scwv 
        type=fc, step=0h to 90h by 3h 
   HH=00 
       stream=mmsf, type=fc, u=m, step=1m to 7m

Attribution

The following wording should be attached to the use of this ECMWF dataset:

1. Copyright statement: Copyright "© [year] European Centre for Medium-Range Weather Forecasts (ECMWF)".
2. Source www.ecmwf.int
3. Licence Statement: This data is published under a Creative Commons Attribution 4.0 International (CC BY 4.0). https://creativecommons.org/licenses/by/4.0/
4. Disclaimer: ECMWF does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use.
5. Where applicable, an indication if the material has been modified and an indication of previous modifications.

The following wording shall be attached to services created with this ECMWF dataset:

1. Copyright statement: Copyright "This service is based on data and products of the European Centre for Medium-Range Weather Forecasts (ECMWF)".
2. Source www.ecmwf.int
3. Licence Statement: This ECMWF data is published under a Creative Commons Attribution 4.0 International (CC BY 4.0). https://creativecommons.org/licenses/by/4.0/
4. Disclaimer: ECMWF does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use.
5. Where applicable, an indication if the material has been modified and an indication of previous modifications

Accessing this dataset

Locations

Currently, these data are available from two different locations:

• ECMWF, with ROOT set to https://data.ecmwf.int/forecasts
• Microsoft's Azure, with ROOT set to https://ai4edataeuwest.blob.core.windows.net/ecmwf

You can use the ECMWF link to browse the list of files.

Examples using wget for products based on the Atmospheric Model high-resolution (HRES) forecasts

In the following examples, [ROOT] should be replaced by one of the locations specified above.

Although all of the examples provided here use wget, curl can similarly be used to download the products.

HRES direct model output

Products at time=00 or time=12

Products at time=06 or time=18

HRES Tropical Cyclone track products

Tropical cyclone tracks products are only available when there are tropical cyclones observed or forecast.

HRES TC-Tracks at time=00 or time=12

HRES TC-track products at time=06 or time=18

Examples using wget for products based on the Wave Model high-resolution (HRES-WAM) forecasts

HRES-WAM direct model output

Products at time=00 or time=12

Products at time=06 or time=18

Examples using wget for products based on the Atmospheric Model ensemble (ENS) forecasts

ENS direct model output products

For all ENS direct model runs

ENS Tropical Cyclone track products

Tropical cyclone tracks products are only available when there are tropical cyclones observed or forecast.

ENS TC-Tracks at time=00 or time=12

ENS TC-track products at time=06 or time=18

ENS Probability products

For the probability products from the Atmospheric model ensemble (ENS) forecast at all times 00, 06, 12 and 18 UTC, stream=enfo and type=ep should be used.

Products are available at time=00 and time=12 only.

There are no ENS probability products for time=06 or time=18.

The steps available are 0h to 144h by 3h and 150h to 360h by 6h. The file format is grib2.

The name of the file to be downloaded depends on the step. Use:

• step=240h in the file name for products at forecast steps 0h to 144h by 3h and 150h to 240h by 6h
• step=360h in the file name for products at forecast steps 246h to 360h by 6h

ENS probability products at 00 and 12 UTC for steps 0h to 144h by 3h and steps 150h to 240h by 6h

ENS probability products at 00 and 12 UTC for steps 246h to 360h by 6h

Examples using wget for products based on the Wave Model ensemble (ENS-WAM) forecasts

ENS-WAM direct model output products

ENS-WAM Probability products

For the probability products from the wave model ensemble (ENS) forecast at all times 00, 06, 12 and 18 UTC, stream=waef and type=ep should be used.

Products are available at time=00 and time=12 only.

There are no ENS-WAM probability products for time=06 or time=18.

The steps available are 0h to 144h by 3h and 150h to 360h by 6. The file format is grib2.

The name of the file to be downloaded depends on the step. Use:

• step=240h in the file name for products at forecast steps 0h to 144h by 3h and 150h to 240h by 6h
• step=360h in the file name for products at forecast steps 246h to 360h by 6

ENS-WAM probability products at 00 and 12 UTC for steps 0h to 144h by 3h and steps 150h to 240h by 6h

ENS probability products at 00 and 12 UTC for steps 246h to 360h by 6h

Download a single field with wget

All of the examples above download a single file containing all of the parameters for that dataset at the specific forecast step or steps.

It is also possible to download of a single field using the HTTP Byte-Range request feature.

Example: download temperature at 2m at step=24h from the 00 UTC HRES forecast

Index files

Each GRIB file is associated with a corresponding index file, accessible by substituting the '.grib2' extension with '.index' in the URL. Index files are text files where each line is a JSON record (JSON details here). Each record represents a GRIB field in the corresponding GRIB file, described using the MARS query language, for example:

{"domain": "g", "date": "20220104", "time": "1200", "expver": "0001", "class": "od", "type": "fc", "stream": "oper", "step": "6", "levelist": "1000", "levtype": "pl", "param": "q", "_offset": 3857250, "_length": 609046}

In addition, the keys _offset and _length represent the byte offset and length of the corresponding field. This allows the download of a single field using the HTTP Byte-Range request. An example is provided in Download a single field with wget above.

Differences between MARS language and file naming convention

There are some minor differences between the normal MARS request language and the open data file naming.

These are summarised in the table for information.

链接：https://confluence.ecmwf.int/plugins/servlet/mobile?contentId=247894981#content/view/247894981

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