the cloud reached 110,000 feet. Although the winds, in generél, were similar to those of the previous bursts, the westerly winds just below the tropopause attained higher speeds than had occurred during the previous tests, 55 to 65 knots at 40,000 feet. Trajectories sre shown in Figure 2.6. Debris reached Mexico City on May 8, and fallout wes widespread over the western pleins states and the Rockies by May 9. Fallout fron this burst continued over the western helf of the United States (with the exception of the Pacific Coast) in significant amounts for a period of more than a week. The fallout from Yankee in this region exceeded, by almost an order of mgnituie, the fallout fron any of the other tests of the series. The westward moving debris appeared to proceed faster than indicated by the low-level trades, reaching Koror by May 6 and Singapore by May 9. Again, it is very possible that high-level essterlies carried the debris, since the 25-30 knot winds required are somewhat faster than expected in the trades of the Western Pacific. 2.6 NECTAR ; The lest test of the series, Nectar, was the only burst detonated from Eniwetok. It occurred st 1820 GOT, May 13, 195k, of the series. The resulting cloud reached 72,000 feet. The easterly winds extended to 20,000 feet, with light westerlies above to the base of the stratosphere. The trajectories from this burst (Figure 2.7) began with a slightly greater component towards the north than for the previous bursts. rT and wes of a somewhat lower yield than the other high-yield tests this time. Daily fallout maps for the remainder of the month, May 22-31, are given with all data extrapolated to 100 days after Nectar because of the arbitrary system of burst assignment used. However, it is likely that the major portion of the fallout reported on these days originated from Yankee. To convert the reported activity to 100 days after Yankee, assuming the debris originating from Yankee, the values given on the maps should be increased by about 30-10%. ne Since Yankee and Nectar were separated by only nine days, it is virtually impossible to distinguish between debris from the two bursts, An attempt to separate the two sources of debris was made for the first week following Nectar, but was not attempted beyond