Several months of continuous operation of two thermodynamic Raman lidars in the frame of WaLiNeAs

The University of Basilicata, in cooperation with ISMAR-CNR, deployed two compact Raman lidars, namely the system CONCERNING and the system MARCO, in Southern France in the frame of the “Water Vapor Lidar Network Assimilation (WaLiNeAs)” experiment. WaLiNeAs, primarily funded by the “French National Research Agency” (ANR), is an international field experiment aimed at studying extreme precipitation events and improving their predictability through the assimilation of water vapour profile measurements from a network of Raman lidar systems into mesoscale numerical models. The experiment has a specific geographical focus on Southern France. The measurement strategy implies the exploitation of seven Raman lidars along the Mediterranean coasts of Spain and France, capable to provide real-time measurements of water vapour mixing ratio profiles over a three-month period starting on October 1^st, 2022.

CONCERNING (COmpact RamaN lidar for Atmospheric CO₂ and ThERmodyNamic ProfilING), developed in the frame of a cooperation between University of Basilicata, ISMAR-CNR and University of Rome, is a compact and transportable Raman lidar system designed for long-term all-weather continuous operation, capable to perform high-resolution and accurate carbon dioxide and water vapour mixing ratio profile measurements, together with temperature and multi-wavelength (355, 532 and 1064 nm) particle backscattering/extinction/depolarization profile measurements. The system relies on a 45-cm diameter Newtonian telescope and on a diode-pumped Nd:Yag laser source, capable of emitting pulses at the three traditional wavelengths of this laser source(355, 532 and 1064 nm), with a single pulse energy at 355 nm of 110 mJ and an average emitted power of 11 watts, based on a pulse repetition frequency of 100 Hz.

MARCO (Micropulse Atmospheric Optical Radar for Climate Observations) is also a compact and easily transportable Raman lidar system, developed around a high- frequency laser source (20 kHz), capable to perform 24/7 high-resolution and accurate CO₂ and water vapour mixing ratio profile measurements, together with temperature and single-wavelength (355 nm) particle backscattering/extinction/depolarization measurements. In the frame of WaLiNeAs, as a result of the restrictions imposed by air traffic authority in the use of the visible and infrared laser radiation, only the 355 wavelength was exploited in CONCERNING, the temperature channel was not available in MARCO, while the CO₂ channels, not needed for the purposes of WaLiNeAs, were temporarily deactivated in both systems.

Both systems have been recently designed and developed and WaLiNeAs represents the first international field deployment for both. CONCERNING was deployed at the University of Toulon in La Garde (Lat.: 43.136040 N, Long.: 6.011650 E, Elev.: 65 m, with continuous measurements since 29 September 2022, i.e. over more than 100 days up to now), while MARCO, was deployed at the Direction de Services Techniques in Port-Saint-Louis-du-Rhône, Camargue (Lat.: 43.392570 N, Long.: 4.813480 E, Elev.: 5 m, with continuous measurements since 19 October 2022, i.e. over more than 80 days up to now). At the time of the submission of this abstract, both system are still operational with a tbc date for the stop of the operation of 31 January 2023. Preliminary results from these two systems will be illustrated and discussed during the Conference.