The small percentage of total debris accounted for by the observing network is somewhat puzzling. Although it must be assumed that a large fraction of the active debris was deposited in the vicinity of the test site, it is also true that the shortcomings of the gummed film tecimique, which have been discussed in previous reports, may be responsible for the effect noted. A suggestion thet increased "stratospheric storage" may be important is indicated by the fact that approximately 1% of the debris from the Castle series was detected, as compared to over Since the three most powerful bursts of the Castle series were considerably larger than the Ivy Mike test, it is possible that a Porro LZ from the Ivy series.# larger fraction of the debris was transported initially into the lower stratosphere. 3.4 METECROLOGICAL INTERPRETATION The total fallout from the Bravo test (Figures 3.3 ami 3.h) clearly show the tendency for the major activity to remsin near the source latitude. In marked contrast with the fallout from the Ivy series, there seems to be no evidence that debris was carried nortinrard around the western side of the Pacific high-pressure cell. This cell is almost non-existent, in the mean, during the winter and | Almost no fallout occurred in Japan, and very little on Iwo Jima ' from the Bravo test, while Ivy Mike resulted in more fallout on Iwo Jima than on any of the other Pacific Islands. The difference between the two tests is a result of the seasonal difference in the location and intensity of the western cell of the Pacific high. *the figures given in Table 6.2 of reference (2) have been revised The revised Observed World-wide Total wary (megacuries as of 1/1/53) Pa following a recalibration of the counting equipment. figures are: ~- 33 -