TOTAL TRITIUM ATOMS PER 107° GRAMS OF. AIR T — | |. | ALTITUDE FEET 147-50,000 58-68,000 |70-78,000 80-83,000 |g8-91,000 T ] 1955 1957 1956 1958 * 4 @ @©@ * wf @ ¢ YF FF TT | I v @ Vv Lo e 7x IQ” atoms gm «+ 2 ¢ e e® 0 l l a a > l | | 1 200 L l | [| EXCESS CARBON -14 ATOMS PER IO-° GRAMS OF AIR Fig, 5 -- Excess C-14 versus total tritium ee -s e, a A oO lOO T = 4s; aa T a = 1O0r - | 300 l