Measurement of OH concentration during a forest fire episode: atmospheric implications for biomass burning

A multipass optical absorption spectrometer has been applied for the observations of the diurnal variation of OH at Tenerife during a forest fire episode. The measurements are compared with results employing a box model showing good agreement with each other before and after the pollution event, but a large discrepancy for the time in between. Among the trace components formaldehyde plays a major role in the OH balance. The observations made are suggested to be typical for biomass burning, which shows that such a scenario will lead to a drastic decrease in the oxidizing capacity of the atmosphere.