I did a search and clicked on a link to:

http://esg.ucar.edu/trackback/query.htm?id=esg%3amodel_gfdl_am2_control_1860_r1i1&session=true

Clicking on the bottom link on the treeview on the left (GFDL AM2 FV Dynamical Core Control-1860 r1i1) returns an HTTP 404 erros