Inference of Hydroxyl Radical Abundances from Combined Satellite and Ground-Based Hydrochlorofluorocarbon Observations

Until recently, Methyl Chloroform was used as a bellwether to determine OH levels but due to its declining concentrations, the need for other means to calculate OH levels is imminent. This work proposes a new way of using three different tracers (HFC134a, HCFC141b, and HCFC142b) to determine hydroxyl levels in the atmosphere using a 9box model. The annual trends of each gas were obtained and it was found that there has not been a significant drop but an increase in two of the tracers' levels despite the implementation of Montreal Protocol. The tropopause was defined around 13kms in the northern and southern latitudes and around 17kms in the tropics. With the regions of each box defined, and the concentrations of the tracers obtained from ACE-FTS instrument and NOAA, the OH levels in the atmosphere were obtained through multiple linear regression.