Trace gas variability in the stratosphere

Abstract

During the second mission of the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) from August 8 to 16, 1997, over 45,000 altitude profiles of infrared spectra were collected. A variety of atmospheric trace gases have been retrieved. Due to its unprecedented spatial and temporal resolution CRISTA data is especially suited to study variability on small scales. Variability of selected trace gases is presented in terms of standard deviations from the zonal means in 5° latitude bands: altitude range is about 15–50 km for the mixing ratios of O 3, N 2O, CH 4, CFC 11, and HNO 3. Results are compared to CIRA 1996, Part III, and agreements or disagreements are discussed. Variability is found to be not constant, but quite variable itself. It is generally higher in winter than in summer. Beyond that there are considerable variations of standard deviations with latitude and with altitude. They show interesting peculiarities that will be discussed. The results indicate that most part of the data variability are atmospheric fluctuations rather than measurement errors.