Temperature of the middle atmosphere observed using satellite constellations
Résumé
The monitoring of temperature in the middle atmosphere has been ensured by a succession of operational sensors onboard NOAA satellites for 4 decades. Due to the different orbits of the platforms and their drifts, influences from atmospheric tides can lead to complex problems when attempting to assess long-term trends. New results, including non-migrating tides, illustrate the need of a constellation of satellites to increase temporal coverage. Sudden Stratospheric Warmings are the largest perturbations in the middle atmosphere, and recent analyses have shown that winter evolutions include some memories that could help seasonal forecasts. A recent Bayesian statistical analysis of mesospheric inversion layers reveals that these events can be grouped into 3 categories. Their occurrence is generally not well captured by meteorological re-analyses, mainly due to the lack of observations. Assessment of meteorological re-analyses using lidar show an obvious lack of variability in the model. On the other hand limb observations can be derived to provide temperature profiles in the middle atmosphere (30-80 km) with a good vertical resolution as demonstrated by GOMOS analyses and can capture the variability of the middle atmosphere with a good accuracy. Such observations can be reproduced with nano-satellites while some technical challenges need to be resolved.