TITLE:
Effects of Chlorine and Chlorine Monoxide on Stratospheric Ozone Depletion
AUTHORS:
Laurie Wei, Ibraheem Alelmi, Sen Nieh
KEYWORDS:
Ozone, Ozone Depletion, Chlorine, Chlorine Monoxide, Photolysis, Dobson Unit
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.14 No.1,
January
29,
2024
ABSTRACT: This paper presents a system
approach of mass balance calculations of ozone and other species under
diffusion-convection-reaction processes to study the impacts of major
ozone-depleting chemicals, chlorine (Cl) and chlorine monoxide (ClO), and the
effect of photolysis on ozone concentrations, ozone depletion, total ozone
abundance, and ozone layer along the altitude in the stratosphere. The
calculated ozone concentrations and profile of the layer followed a similar
trend and were generally in good agreement with the measurements above the
tropical area. The calculated peak of the layer was at the same
mid-stratosphere at Z = 30 km with a peak concentration and total ozone
abundance about 20% higher than the measured peak concentration of 8.0 ppm and
total abundance of 399 DU. In the presence of Cl and ClO, the calculated ozone
concentrations and total abundance were substantially reduced. Cl generally
depleted more uniformly of ozone across the altitude, while ClO reduced
substantially the ozone in the upper stratosphere and thus shifted the peak of
the layer to a much lower elevation at Z = 14 km. Although both ClO and Cl are
active ozone-depleting chemicals, ClO was found to have a more pronounced
impact on ozone depletion and distribution than Cl. The possible explanations
of these interesting phenomena were discussed and elaborated. The approach and
calculations in this paper were shown to be useful in providing an initial
insight into the structure and behavior of the complex ozone layer.