Tropopause region temperatures and CFC 11 mixing ratios from CRISTA 2

[1] Nearly global measurements of CFC 11 (CFCl3) in the upper troposphere and stratosphere are presented. Data are from the CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA 2) experiment in August 1997. They are the first global CFC 11 data set that covers the altitude regime 8 km to 28 km. A new temperature data product was developed for the CFC 11 retrieval by combining high accuracy of UKMO temperatures with high spatial resolution of CRISTA temperatures. At midlatitudes these temperatures and resulting CFC 11 mixing ratios are compared to in situ measurements and the regional CTM system EURAD. Measured temperatures agree within about 1 K (except at the cold point tropopause). CFC 11 mixing ratios agree within 0–15%, depending on altitude. Model temperatures of EURAD have a small warm bias (1 K). Model CFC 11 has a low bias of 15–30 pptv (10% at 147 hPa). The high resolution transport model data are for the first time combined with dense and reliable CFC 11 measurements from space to study specific dynamical features. Emphasis is on a midlatitude blocking event characterized by an omega circulation pattern with a persistent cutoff low at its western wing. At low latitudes our CFC 11 mixing ratios and temperatures suggest a warm bias of the UKMO temperatures near the tropical tropopause.