The closed loop does not act like an inductor in my understanding as it is perpendicular to the flow. To place them in to a grounding system at the base of the building helps to form an equal potential plane, but little to no current flows through them due to the equal potential plane they form, and, as such they do not provide additional "drain points" (for lack of being able to think of a better term) for the current of a lightning strike.
I close the loop everytime, but only have a ground loop installed at the base of the building. Loops further out away from the building are a waste of resources.
Been awhile since I've read tech papers on the subject. Try the military handbook "Grounding, Bonding, and Shielding for Electronic Facilities" mil-hnbk-419a, Motorola "Standard and Guidlines for Communication Sites" 68P81089E50-A, and if still available Polyphaser had some very well written manuals on the subject. Other references are to numerous and of the three mentioned I don't really care for the military handbook.
For deep stuff try the papers available at
www.jolr.org (the Journal of Lightning Research).
Shane
