Comparison of stratospheric measurements made by CHAMP radio occultation and Stratéole/Vorcore in situ data

Abstract

This paper compares measurements in the Antarctic stratosphere during austral spring and summer made by the CHAMP radio-occultation satellite and in situ long-duration super-pressure balloon (SPB) observations during the Stratéole/Vorcore campaign. Initial analysis compares near-simultaneous and co-located temperature observations made by these instruments and finds excellent agreement between these two very different sets of measurements. The mean bias between the data sets is -0.52 K, CHAMP RO temperature being cooler than the balloon measurements, and the standard deviation of the temperature differences is 1.6 K for the paired observations. This paired data set also allows us to show that an empirical correction used to remove the influence of radiative heating on the balloon sensors does not produce any bias. An initial comparison of the magnitude of gravity wave activity observed by each instrument shows relatively poor agreement. Analysis suggests that this agreement can be improved slightly by accounting for the observational filtering associated with the CHAMP measurements. Copyright 2008 by the American Geophysical Union.