sr ACTIVITY, DIS/MIN PER 1000 SCF
LTT
+ OCTOBER 1963
#e @
10°
wr
an
ite
SOPN
iy
py
yp
pt
60PN
tp
30°N
yp
gy
fl
ly
°
ps
30°S
40°S
90S
LATITUDE
Fig. 16—Horizontal profiles of Sr activity at 65,000 ft.
sphere during the winter season. The concentrations decreased at all
latitudes between October 1963 and May 1964, no doubt as a result of
fallout of nuclear debris to the troposphere.
With the use of the estimated distributions in the stratosphere,
including some shown in Figs. 10 to 13, the stratospheric burdens of .
9Sr between mid-1961 and late 1963 have been calculated. The results
are presented in Table 1. Before the renewal of weapons testing, the
burden was about 0.9 Mc. By early 1962 it had reached about 2.0 Mc,
and by early 1963 it had reached perhaps more than 7 Mc. During 1963
the burden decreased, however, reaching 4.4 Mc by late 1963.
Table 1—STRATOSPHERIC BURDENS OF Sr
Megacuries of *%Sr
Time interval
June through September 1961
October through December 1961
January through April 1962
May through August 1962
September through October 1962
November through December 1962
January through April 1963
May through August 1963
September through December 1963
Northern
Southern
Total
hemisphere
hemisphere
burden
0.37 + 0.13
~1.6
~0.5
0.47 + 0.17
0.4 + 0.1
~1.0
~0.9
~2.1
2.0 + 0.3
~3.5
2.2 +4 0.7
5.6 + 1.9
6.7 + 1.7
1.0 + 0.3
0.8 + 0.3
0.7 + 0.3
3.2 + 0.8
6.4 + 1.9
7.424 1.7
3.3 + 0.6
1.1+ 0.4
4,440.7
1.6 + 0.3
2.5 + 0.5
4.9 41.5
0.9 + 0.3
5.8 + 1.5