Validation of Aura MLS HOx measurements with remote‐sensing balloon instruments

Satellite measurements of OH and HO2 obtained by the Aura MLS instrument are compared to the balloon‐borne BOH and FIRS‐2 instruments. All measurements are also compared with constrained photochemical model calculations. On average, both balloon measurements of OH agree with MLS within 17% over 25–40 km and the measurements agree with the model within 12%. The three measurements for column of OH above 40 km agree within 8% and the mean is 12% below the model. Measurements of HO2 from FIRS‐2 and MLS agree on average within 23% over 25–40 km and the differences are generally within the experimental precision. The HO2 measurements agree with the model within 14%. Measurements of HO2 for the column over 40–60 km agree within 16% and the mean measured column agrees with the model within the experimental precision. Our observations do not appear to indicate a “HOx dilemma.”