DISTRIBUTION OF RADIOACTIVITY WITH HEIGHT
IN NUCLEAR CLOUDS
GILBERT J. FERBER
U. S. Weather Bureau, Washington, D. C.
ABSTRACT
During
Operation Dominic I at Christmas Island in 1962, aircraft
sampling of nuclear clouds was done soon after cloud stabilization
to investigate the amount of radioactive debris that stabilizes in the
troposphere and its distribution with height. The detonations studied
were all air bursts over water. Some data for surface bursts obtained
during Operation Redwing in 1956 are used for comparison. Results
indicate that for air bursts less than 1% of the total radioactivity is
present in the stem of the nuclear cloud, It is estimated that about
One-third of the total debris from the Christmas Island cloudsinitially
Stabilized in the troposphere.
Project Stemwinder has shown that in-cloud dose-rate monitoring
by aircraft is a relatively simple and economical way to obtain information on the distribution of radioactive debris in a nuclear cloud, Used
in conjunction with limited’ radiochemical analysis of samples, this
type of monitoring could produce a reliable inventory of the debris in
a nuclear cloud.
INTRODUCTION
The objective of Project Stemwinder was to probe and sample nuclear clouds as soon as possible after cloud stabilization to investigate the amount of radioactive debris that stabilizes in the troposphere
and its distribution with height. Sampling was done with RB-957 air-
craft of the 1211th Test Squadron under the scientific direction of the
Atmospheric Radioactivity Research Branch, U. 5. Weather Bureau.
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