Intercomparison of Odin/SMR Ozone measurements with MIPAS and balloon sonde data

The Sub-Millimetre Radiometer (SMR) on board Odin measures various important atmospheric species, including stratospheric ozone. In this study we compare the three versions (v1.2, v2.0 and v2.1) of level 2 Odin/SMR global stratospheric ozone data to coincident level 2 MIPAS V4.61 and balloon sonde stratospheric ozone data during 2003. The most current product from Odin/SMR (at time of writing), the v2.1, showed the smallest systematic differences when compared to coincident MIPAS and sonde data. Between 17 and 55 km, v2.1 values agreed with MIPAS within 10% (a maximum of 0.42 ppmv), while comparisons to sonde measurements showed an agreement of typically 5-10% between 22 and 35 km (less than 0.5 ppmv below 33 km). Tropical latitudes below 35 km preseneted the largest absolute systematic differences between v2.1 and sonde coincidences, where Odin/SMR was systematically lower by ~0.9 ppmv (more than 10% difference) at approximately 30 km. Comparisons concerning the previous two Odin/SMR versions showed much larger systematic differences, especially at the higher and lower stratospheric altitudes. The main conclusion here is that we suggest that v2.1 of Odin/SMR ozone data should be used for scientific studies