Was the "unsealed...opening to the "box" at the top (1 mile elevation), or the bottom (sea level)?? (Won't be "STP" at both points, so drop the "IOW" part and just say "1 cubic mile of air at STP"?). Anyway, I tend to agree with "BiguN" on this one:
"Just so you know, there are plenty of people here with the ability to answer the question but, it seems, no one thought it worth the effort.".
Better to burn brain power on ideas to save the USA from a debt implosion, society's norms/morals unwinding, hyper-inflation, CW2 or something like that.