To log on to webpub, you must either have your VPN activated or be on a computer connected to the NCAR network.
$ ssh <user>@webpub.ucar.edu
Once you are connected to webpub,
/web/image/pub/DART corresponds to https://www.image.ucar.edu/pub/DART/
This directory has permissions:
drwxrwsr-x 37 thoar image 8192 Apr 22 2020 .