USING A BOX-GRS MODEL TO STUDY THE ROLE OF INPUT PARAMETERS ON ESTIMATED PEAK O3 HOURLY CONCENTRATIONS

PINEDA ROJAS, ANDREA L.; DAMIAN BIKIEL

Brujas

Conferencia; HARMO2019; 2019

HARMO

A local sensitivity analysis is performed using a box model to study the role of each parameter on the maximum ozone (O3) concentration estimated with the Generic Reaction Set (GRS) under a wide range of conditions. Isopleth diagrams with 5 ppb resolution were built and sensitivity indexes were calculated for ±1 ppb changes in the initial concentrations of O3 and the precursor species: nitrogen oxides (NOx) and reactive organic compounds (ROC). Results show that apart from the NOx-limited region, where the system is extremely sensitive to NOx, the dominant variable is the initial ozone concentration with sensitivity indexes increasing towards a low NOx - high ROC regime. Regarding the reaction rate coefficients, the system is the mostly sensitive to (not small) changes in the coefficient corresponding to the pseudo reaction converting ROC to radical species under urban conditions, but is more sensitive to the reactions corresponding to the removal of NOx under rural conditions. These findings highlight the importance of the initial ozone concentration estimates and the choice of scheme variables parameterizations under different conditions/environments.