Phys.org  November 1, 2021 The hydroxyl radical (OH) sets the oxidative capacity of the atmosphere and thus, profoundly affects the removal rate of pollutants and reactive greenhouse gases. OH estimates for past and future periods rely primarily on global atmospheric chemistry models. The models disagree ± 30% in mean OH and in its changes from the preindustrial to late 21st century. A simple steady-state relationship that accounts for ozone photolysis frequencies, water vapor, and the ratio of reactive nitrogen to carbon emissions explains temporal variability within most models, but not intermodal differences. A team of researchers in the US (University […]