Update of stratospheric temperature interannual variability and trends from space sounders and ground-based lidars observations

International audiencethe stratosphere is expected to cool, in conjunction with the global warming at the surface and in the troposphere, due to the increase of greenhouse gas concentration in the atmosphere, and also to stratospheric ozone loss. this is already observed but the rate of cooling is not constant and there is still a debate on its amplitude. several other factors may influence the evolution of the stratospheric temperature. external forcings, like the solar variability that modulate the UV solar flux and strong volcanic eruptions injecting aerosols in the stratosphere, participate to its decadal variability. the variability of the stratospheric dynamics is also adding some complexity to the system. For instance global climate models predicts an increase of the occurrence frequency of sudden stratospheric warming (SSW) events not yet confirmed by the observations. A monitoring of the stratospheric temperature evolution is crucially needed to better understand the complexity of the processes playing a role in the coupling between the stratosphere, the troposphere and the climate.the stratospheric temperature is measured at a global scale by satellite instruments; mainly microwave sounders aMsU (advanced Microwave sounding Unit) on board meteorological satellites. these sounders are very useful to provide the global overview but may suffer from biases and orbital drifts and have a poor vertical resolution in the upper stratosphere. since 2000 radio-occultation sensors, among them the Us-taiwan COsMiC constellation, provide well-resolved and accurate temperature profiles but limited to the upper troposphere-lower stratosphere. rayleigh lidars implemented within the nDaCC (network for the Detection of atmospheric Composition Change) international network measure accurately the temperature profile from the middle stratosphere to the upper mesosphere but in a very few locations. they are used climate change monitoring, dynamics studies and satellite validation.in this presentation we will present an update of the interannual variability and trends in the stratospheric temperature from aMsU, rayleigh lidar and radio- occultation measurements. similarities and differences in the temperature evolution captured by these various sensors will be evaluated. the contribution of anthropogenic and natural forcings to the observed changes will be discussed. a particular focus will be given to the role of SSW events to the stratospheric temperature evolution as a function of latitude and season