Access ECMWF Data via python script

Question

I want to access ECMWF data via a python script. I am not sure how to do that. I followed the instruction given on the website: Accessing ECMWF data server in batch

Unfortunately it says: "This method is only supported to UNIX platforms with Python." I am on a Windows platform. Does that mean I can't access the data from ECMWF? If this method is only for UNIX-Users only, is there an alternative for Windows-User?

So far I did the following:

created textfile in my homedirectory with content: C:\User\Name\ .ecmwfapirc.txt

{
  "url"   : "https://api.ecmwf.int/v1",
  "key"   : "my-API-code",
  "email" : "my.email@example.com"
}

Next I installed python library: ecmwfapi

python -m pip install https://software.ecmwf.int/wiki/download/attachments/56664858/ecmwf-api-client-python.tgz

Last but not least I created the python script which looks like:

 #!/usr/bin/env python
 from ecmwfapi import ECMWFDataServer
 server = ECMWFDataServer()
 server.retrieve({
     "class": "e2",
     "dataset": "era20c",
     "date": "2010-01-01/to/2010-12-31",
     "expver": "1",
     "levtype": "sfc",
     "param": "167.128",
     "stream": "oper",
     "time": "12:00:00",
     "type": "an",
     "target": "CHANGEME",
 })

I am not sure if the python script is correct either. Also I don't know whether the location of the python script is important when executed.

Answer 1

I know this topic is six months old, but for reference: the ECMWF API is now supported on Windows. Please see here for details

The OP created a file '.ecmwfapirc.txt'. This is wrong, it has to be named '.ecmwfapirc' (without extension).

From what I can see your retrieval script is correct. There is a web interface to help you create your retrieval script: http://apps.ecmwf.int/datasets/ At the end click 'View MARS request'

The location of the retrieval script script does not matter; only if you save the output to the same location, the location has to be writeable.

Answer 2

You can create a UNIX environment from Windows by several ways.

• Cygwin

  is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment. (source)

• Run Linux in VirtualBox. VirtualBox is a free and open-source cross-platform software (among others) that runs other operating systems from inside of another. In your Windows computer, you would install VirtualBox. Then, pick a Linux distribution (e.g. Ubuntu) and install that operating system inside VirtualBox. Here's a guide for Ubuntu.

• Run Ubuntu Linux from a USB stick. After you make the bootable USB stick, you choose to boot from that device at startup. Then you have a Linux enviroment, although each time you restart, you'll have to re-configure the network connection, etc.

All 3 methods will have standard python installed. You'll have to install the ECMWF client yourself. If your project is longer-lasting, you may considering buying some low-cost, used hardware and running something dedicated. Additionally, Linux cloud instances are very cheap, and even free for 12 months from some providers (AWS) and can be as cheap as $3 per month for other cloud providers.