On the Upper Currents in Low Latitudes of the Northwestern Pacific Ocean at the Beginning of March, 1954

Meteorological investigation on the explosion at Bikini Island. I

Abstract

Weather situations in low latitudes of the northwestern Pacific at the beginning of March 1954, when an H-bomb experiment was performed at Bikini, are analyzed. Some of the results are as follows:
(1) Broadscale pattern in pressure field shows an unstable condition in the vicinity of Bikini.
(2) Streamline patterns at lower, middle and upper levels in the troposphere are different, and the maximum of wind speed exists near the level of the tropopause.
(3) Rather strong easterlies have prevailed in the stratosphere throughout this period.
(4) There are divergence and convergence areas to the west of Eniwetok and to the south of Kwajelein respectively.
(5) The upper currents over Bikini are as follows: 0-2km 3-17km >18km easterlies westerlies easterlies
(6) Height of the tropopause in low latitudes during this period is about 16km, with the maximum at about 12-13°N.
(7) Time-cross sections of upper currents for some station show that easterlies are prevailing in the lower layer below 3km, westerlies are prevailing in the layer between 3km and the height of tropopause, and easterlies are prevailing again in the higher level above 21km. The maximum wind speed in the higher easterlies is 65 mph which is observed at the level of 25km over Guam.
The maximum in the westerlies is 115 mph which is observed at the level of 14km over Wake.