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The chemical form of cosmogenic radioactive 38 Cl and 39 Cl in the lower stratosphere
Author(s) -
Rowland F. S.
Publication year - 1978
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl005i001p00009
Subject(s) - stratosphere , chlorine , isotopes of chlorine , radiochemistry , nuclear reaction , chemical reaction , radioactive decay , chemistry , analytical chemistry (journal) , physics , atmospheric sciences , nuclear physics , environmental chemistry , organic chemistry , biochemistry
The cosmogenic radioisotopes 38 Cl (t ½ = 37.3 min.) and 39 Cl (t ½ = 55.5 min.) are formed in the stratosphere in detectable quantities, and participate in the stratospheric chlorine cycles. The predominant expected chemical forms for these radioisotopes are ClO and/or ClONO 2 throughout most of the stratosphere. The rates for formation of HCl are sufficiently slow that most 38 Cl and 39 Cl atoms undergo radioactive decay before ever reacting to form HCl. The measurement of the fraction of 38 Cl and 39 Cl in the forms ClO and ClONO 2 , with a concurrent NO 2 measurement, can be used to measure in situ the stratospheric formation rate for ClONO 2 . Such experiments could be conducted at altitudes accessible to aircraft experiments.