Feature request: Eliminate references to IMaGe web server in the documentation and tutorials

[johnsonbk]

Use case

URLs in tutorials will break when the IMaGe server gets deactivated.

Is your feature request related to a problem?

Yes, the WRF tutorial references this URL: http://www.image.ucar.edu/wrfdart/tutorial/wrf_dart_tutorial_23May2018_v3.tar.gz

Describe your preferred solution

We need to find a place to host tar files that can be accessed by the general public. Options described below.

Describe any alternatives you have considered

• Google Drive: It's possible to use the "Get link" functionality in the DAReS team shared folder in Google Drive if the file is in the root directory -- not in the pub directory. However, downloading such files from the command line is problematic. It was possible in the past to wget a public file from Google drive. However, that functionality is now deprecated. I don't think this option is feasible.
• Commandeering unrelated web services for file hosting: I tried (unsuccessfully) uploading large files to web services such as Github (25MB file size limit) and wiki.ucar.edu (100MB file size limit) to use those sites for hosting.
• Local FTP Server: CGD maintains an ftp server from which users can download CESM forcing data: ftp://ftp.cgd.ucar.edu. Since our file hosting needs are less demanding than the CGD server, we could have a small file server connected somewhere in the DAReS offices that hosts these files. I don't know how difficult (with respect to the internal IT requirements) this would be to set up. It would also be offline during the Mesa Lab power down weekends.
• Cloud Server: The Cybersecurity Program Office maintains a list of approved vendors (login required to view) that UCAR can use (AWS, DigitalOcean). We could set up an FTP server and pay a monthly subscription.
• Data Access Nodes: The WRF-Chem dataset is hosted on the data access nodes: https://wiki.ucar.edu/display/DIME/WRF_CHEM+dataset+Globus However, these file are purged every 45 days.