30
~~
20
~
sy
Oo
mh
oO
—
~
~O
~
“~.
O
_
Oo ON
a,
Ue
~
x
“93
Oo DO
~
Og,
Ss
~*~.
_
Oo sy
144
/dpm Sr
90
~
—
dpm Ce
ONG
—
QL
4
On 6
Oo“
Dw _
~
oO
° MiAImlu{yvlA;/S{O|N{O]ylE[Mlaimlu fu fAl/Sfo{[NiDO{[JIFIMIAIM fu
1958
1959
1960
Fig. 2 -- Variation with time of the monthly average for Cel44/5r90 in
samples collected between 60,000 and 70, 000 feet in the trop-
ical stratosphere (30°N - 30°S)