ATMOSPHERIC DISTRIBUTION OF NITROUS-OXIDE

Recent extensive measurements by the authors and co-workers indicate extremely little variation of nitrous oxide in the troposphere, with a concentration of approximately 330 ppb vol/vol. Continuous measurements made over a 3-month period showed a variation of less than 1%. This work was motivated by the hypothesis that increased use of inorganic nitrogen fertilizers might lead to an increase in tropospheric N//2O levels and a concomitant 20% decrease in stratospheric ozone by the turn of the century. The only large-scale variation found for nitrous oxide in the troposphere appears to be associated with the northeast trade winds system and may originate in North Africa. There also appears to be a bias inherent in the different methods of measuring N//2O, and a program of intercalibration among the laboratories making measurements is necessary to resolve the question of the absolute concentration of nitrous oxide in the atmosphere.