ear
EXFLENATORY NOTE
The data inclosed in this report supplements data submitted
previously in AFOAT-1 reports entitled "Distribution of Carbon-lh
Activity within the Stratosphere," Appendix I, dated 01 April 1957,
(Preliminary Draft}, and Appendix II, "Data Supplement to Distribution
of Carbon-1l Activity within the Stratosphere," dated 27 January 1958,
(Preliminary Draft). The data in this report results from the continued
collections of atmospheric whole air serples over the period fran
Noventer 1957 through June 1958.
This report, with the two previous
reports listed above, provide the reader with continuous data over the
interval from September 195 thrceugh June 1958,
For purpose of clarity, the data in this report are divided into
two tables: the data of Table I resulting from the analysis of balloon
collections of stretcspheric wnole air from four separate sites, a
collection procedure described briefly in the initial deta report; the
data of Table II resulting from aircraft collections of whole air made
at a latitude of 7h°N near Point Farrow, Alaska.
For purpeses of com-
parison, data from sampling at each location are reported in mean
altitude groupings dependent upon the altitudes from which the collections
were made»
The data includes the excess carbon-l) activity as observed in the
COg fraction of the whole air sample. The normal abundance of CO2 in
wnole air is teken as 0,031 mole percent. Subtracted cosmic-ray back=
ground is 73 x 10> atoms carbon-lh per gram of air. In addition to the
carbon-1h data, this report includes the associated gross (10.7 year)
Kr-85 activity per gram of air as observed in the krypton fraction of
the whole air collection, The abundance of krypton in air has been
determined as 1.12 x 10-2 role percent, Detericination of gross Kr-85
activity in the krypton frection of the sample is mede by Argonne
heticnal Laboratory utilicing methods of gas counting quite sirilar to
those utilised in the carbon-14 determinations,
Cne s
of the absolute error in determining the Kr-35 concent
less than 5% of the measured activity.
rd deviation
fircraft collections of whole air «ere made py utilizing a 2-36
aireraft equivped with a) cubic feet per minute Kidde tywe coxpressor
S
in conjunction with a high pressure bottling system. Four main altitudes
of collections are reported to a maximum altitude of 10,000 fect m22n sea
Tevel e