Le Port, Reunion Island, 21°S, 55°E
Reunion Island is a volcanic island located in the Indian Ocean at about 800 km east of Madagascar. In the context of global climate changes, Reunion Island is a very interesting site in atmospheric research for the detection of trace gases and the study of the transport of biomass burning plumes.
Reunion island is part of the ground-based Network for the Detection of Atmospheric Composition Change (NDACC). Ground-based Fourier transform infrared (FTIR) solar absorption measurements are performed by BIRA-IASB at the University of Saint-Denis since 2002 and at the new observatory located at Maido mount (2200m a.s.l.) since 2012. To complete these measurements, BIRA-IASB operates also MAXDOAS measurements at Le Port since April 2016 (after a first installation at Saint-Denis from July 2004 to July 2005).
Instrument and operationRecently, in April 2016, a new MAXDOAS instrument has been installed on the top of the ARDA (Association de Recherche et de Développement pour l’Aquaculture, now called Hydro-Reunion) building at Le Port, the main harbour city located at the extreme northwest corner of the island. It is a full automated dual-channel system covering the 300-540 nm range. It consists in a thermo-regulated box containing two spectrometers located inside the building. An optical head is mounted on a commercial suntracker located outside and connected to the spectrometers via optical fibers. The instrument alternates off-axis measurements in the direction of the sea as well as direct sun measurements. It should allow to detect all primary gases (NO2, O3, HCHO, SO2)