An empirical correlation between surface O3 and its factors

Observations were made of surface O3, NOx, UV radiation, and meteorological parameters at DBR, Guangdong province, and the statistical relationship of O3 to its factors (NOx, water, scattering, UV radiation) was studied. An empirical method was applied to estimate O3. The calculated value agrees well with that observed under different sky conditions, and averaged relative biases of daily O3 concentrations in clear and all sky conditions were ⩽7%. A good correlation was found between O3 and the ratio of NO2/NO in clear and all sky conditions, and correlation coefficients between O3 and NO2/NO were more than 0.90. This empirical method can be used as a tool to analyze the relationship between O3 and the factors affecting it. The analysis shows that O3 is more sensitive to the change of NO and NO2 than that of other factors.