FISSION PRODUCTS IN THE ATMOSPHERE AND RAIN
613
ment of !*4Sb in terms of the Brewer—Dobson model,”> which implies a
meridional northward movement of stratospheric air. However, since
definite information on the /*4Sb production sites and timesis not available at present, this reasoning is, of course, inconclusive,
Table 3 shows the distribution of “Mn in the northern strato-
sphere. High concentrations of 4vMin were observed in April 1963 at
Table 3—CONCENTRATIONS OF 4Mn AND Sr IN THE NORTHERN
ATMOSPHERE BETWEEN 60 AND 738°N
“Min,
Altitude,
103 ft
per 109 scf
July 26, 1962
July 26, 1962
45
67
706
17,734
336
430
2,2
4.4
Sept. 7, 1962
Sept. 7, 1962
60 —64
63-64
10,012
13,036
407
447
2.9
3.5
Jan. 22, 1963
Jan. 24, 1963
65
45
6,950
870
4,360
420
2.7
3.3
Apr. 16, 1963
25
Apr. 16, 1963
45
4,750
July 16, 1963
July 16, 1963
July 16, 1963
Sept.
Sept.
Sept.
Sept.
dates
Apr. 16, 1963
Apr. 16, 1963
Apr. 16, 1963
Apr. 16, 1963
3, 1963
3, 1963
5, 1963
22, 1963
30
35
dis /min
Sr,
Sampling
95
per 103 scf
46
54in/99Sr*
3.2
495
1,010
10.0
13.1
3,060
5,330
5,330
2,380
0.9
3.0
40
50
60
1,030
2,010
3,550
597
1,700
3,320
2.7
1.9
1.7
55
65
30
43
1,870
1,530
31
210
1,570
1,705
23
135
1.9
1.4
2.1
2.5
a5
65
3,140
8,400
disy;min
2,400
3.1
*As of July 1, 1962.
an altitude range of 30,000 to 35,000 ft, but no sudden change of the
'4S_ and 1°sb concentrations relative to “Sr was observedatthis
altitude. Thus it appears that the “Mn was produced independently in
one of the nuclear devices detonated during the fall of 1962, It is interesting to note that the “Mn concentration at this altitude became extremely low by September 1963,
Concentration of fission products from the nuclear detonation by
Communist China on Oct, 16, 1964, are given in Fig. 7. Determinations were made from rain collected at Fayetteville, Ark., on Oct. 26,
1964,
ACKNOWLEDGMENTS
The Project Star Dust filter samples were made available by the
U. S. Defense Atomic Support Agency. Flight data supplied by H. W.
Feely, Isotopes, Inc., Westwood, N, J., are gratefully acknowledged.