Iodine in the lower stratosphere can impact ozone levels. Scientists studied how iodine might be causing lower stratospheric ozone to decrease. They used a model called TOMCAT to explore this idea. The research revealed that the presence of iodine in the lower stratosphere could be a significant factor in the observed trends of declining ozone. This finding suggests that iodine's role in the ozone cycle is essential to understand for predicting future changes in the ozone layer and its potential implications for the environment.