µDIAL, an innovative lidar instrument, is currently being developed at LSCE in collaboration with DT INSU (https://www.dt.insu.cnrs.fr/), the SAFIR service unit (https://www.safire.fr/) and the Institute of Optics (https://www.institutoptique.fr/). This national instrument should allow the altitude-resolved measurement of water vapour content in the lower and middle troposphere using a DIAL (differential absorption lidar) approach. Such a measurement is a fundamental societal issue in the current context of climate change, which is already leading to drastic changes in the meteorology of our planet and significantly influencing the magnitude of extreme weather events (drought, intense precipitation associated with floods). The µDIAL technology allows us to project ourselves towards new means of monitoring and anticipation by coupling it with the new generation of forecasting models whose spatial resolution makes it possible to simulate and anticipate extreme weather events. It is an instrument that is part of the resilience approach that our societies must adopt in the face of unavoidable climate change.
Operating at about 828 nm, µDIAL offers a spatial resolution of 100 m up to ~4 km altitude, where most of the atmospheric water vapour is located. Thanks to its robustness, this innovative system based on laser diodes and solid-state amplification will allow airborne deployment for the first time on SAFIRE aircraft with a large range. It will be made available to the French atmospheric science community and will be operational by day and night, which represents a competitive advantage over other lidar technologies.
A strong potential for evolution is to be expected. In particular, µDIAL will be capable in the future of measuring temperature and aerosol concentrations: essential parameters for understanding the climate evolution of the Earth system.
