The assessment of changes induced by human activities on Earth atmospheric composition and thus on global climate requires a long-term and regular survey of the stratospheric and tropospheric atmospheric layers. The objective of this paper is to describe the atmospheric observations performed continuously at Reunion Island (55.5° east, 20.8° south) for 15 years. The various instruments contributing to the systematic observations are described as well as the measured parameters, the accuracy and the database. The LiDAR systems give profiles of temperature, aerosols and ozone in the troposphere and stratosphere, probes give profiles of temperature, ozone and relative humidity, radiometers and spectrometers give stratospheric and tropospheric integrated columns of a variety of atmospheric trace gases. Data are included in international networks, and used for satellite validation. Moreover, some scientific activities for which this station offers exceptional opportunities are highlighted, especially air mass exchanges nearby dynamical barriers: (1) On the vertical scale through the tropical tropopause layer (stratosphere–troposphere exchange). (2) On the quasi-horizontal scale across the southern subtropical barrier separating the tropical stratospheric reservoir from mid- and high latitudes.
lidar; reunion island; tropospheric; stratospheric; geophys; ftir; environ; subtropical; troposphere; laser; saoz; cyclone; keckhut; ozone; monit; baray; hauchecorne; royal society; bencherif; raman; water vapor; baldy; stratosphere; ndsc; tropopause; southern subtropical barrier; dynamical; tropospheric ozone; climate change; southern tropics; tropical convection; spectrometer; saint denis; southern hemisphere; ozone probe; tropics; validation; photomultiplier tubes; southern subtropics; reception system; ftir instrument; gravity waves; chane ming; good agreement; altitude station; saoz spectrometer; second campaign; middle atmosphere; indian ocean; vertical distribution; ozone probe program; water vapor measurements; observation zenitale; radio soundings; radio probes; spectral range; seasonal cycle; rossby wave; tropopause folds; laser beam; excimer laser; subtropical barrier; mechanical chopper; electronic chain; tidal perturbations; special attention; ozone lamina; spectral bands; spectral band; lidar measurements; dynamical processes; special interest; upper stratosphere; additional soundings; tropical cirrus clouds; reunion site; holographic grating; lidar system; stratospheric ozone; atmospheric dynamics; ozone measurements; tropical cyclones; doppler radar observations; subtropical barriers; troposphere region; water vapour; tropical troposphere; stratospheric change; laboratoire atmospherique; institut spatiale; remote sens; high latitudes; satellite validation; lidar systems; atmospheric observations; lidar observations; reunion; convection