Intercomparison of satellite and aircraft observations of ozone, CFC-11, and NOy using trajectory mapping

The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRI STA) satellite measured global distributions of over 15 trace constituents at high horizontal resolution (<500 km), The CRISTA mission began shortly b efore the end of the Airborne Southern Hemisphere Ozone Experiment and Meas urements to Assess the Effects of Stratospheric Aircraft (ASHOE/MAESA) airb orne measurement campaign. CRISTA measurements of ozone, CFC-11, and HNO3 a re available below 20 km, in the altitude range sampled by the ER-2 aircraf t during ASHOE/MAESA. However, the time separation between the two missions makes a direct comparison of the data impossible. In this study, trajector y techniques are used to compare CRISTA measurements of ozone, CFC-11, and HNO3 with ER-2 measurements taken during the last two flights of ASHOE/MAES A on November 2 and 4, 1994. Visual comparison of CRISTA and ER-2 data from the November 4 flight is generally good. Mean tracer gradients across scal es of similar to 1000 km, as well as absolute mixing ratios agree well with those measured from the ER-2, Correlation coefficients for coincident pair s of ER-2 and CRISTA measurements are between 0.68 and 0.80. The comparison for the November 2 flight is poor. We argue that the poor agreement for th is flight maybe due to both smaller CRISTA measurement density as well as r apid stretching in the air mass sampled by the ER-2 on November 2.