ERROR ANALYSIS FOR THE GROUND-BASED MICROWAVE OZONE MEASUREMENTS DURING STOIC

We present a formal error analysis and characterization of the microwa ve measurements made during the Stratospheric Ozone Intercomparison Ca mpaign (STOIC). The most important error sources are found to be deter mination of the tropospheric opacity, the pressure-broadening coeffici ent of the observed line, and systematic variations in instrument resp onse as a function of frequency (''baseline''). Net precision is 4-6% between 55 and 0.2 mbar, while accuracy is 6-10%. Resolution is 8-10 k m below 3 mbar and increases to 17 km at 0.2 mbar. We show the ''blind '' microwave measurements from STOIC and make limited comparisons to o ther measurements. We use the averaging kernels of the microwave measu rement to eliminate resolution and a priori effects from a comparison to SAGE II. The STOIC results and comparisons are broadly consistent w ith the formal analysis.