Ozone Loss in Stratosphere

HYPOTHESIS 1

The observed long-term trend in mid-latitude Northern Hemisphere ozone in the lower stratosphere over the last two decades is the result of increased catalytic loss of ozone in the lower stratosphere by the rate limiting halogen radicals ClO, BrO, and IO. The observed variability of ozone in the lower stratosphere is the result of factors that modulate those halogen radicals, specifically water vapor, aerosol loading and temperature.

This hypothesis, the correctness of which will be tested in the course of this proposed research, addresses a central tenet in the latest WMO report: Scientific Assessment of Ozone Depletion: 2002 that has just been released. In the Scientific Summary for the key Chapter 4, under, “Attribution of Past Changes in Ozone,” on page 4.2, it is stated: