Cézeaux-Aulnat-Opme-Puy De Dôme: a multi-site for the long-term survey of the tropospheric composition and climate change

Abstract

Abstract. For the last 25 years, CO-PDD (Cézeaux-Aulnat-Opme-puy de Dôme) has evolved to become a full instrumented platform for atmospheric research. It has received credentials as a national observing platform in France and is internationally recognized as a global station in the GAW (Global Atmosphere Watch) network. It is a reference site of European and national research infrastructures ACTRIS (Aerosol Cloud and Trace gases Research Infrastructure) and ICOS (Integrated Carbon Observing System). The site located on top of the puy de Dôme mountain (1465 m a.s.l.) is completed by additional sites located at lower altitudes and adding the vertical dimension to the atmospheric observations: Opme (660 m a.s.l.), Cézeaux (410 m), and Aulnat (330 m). The integration of different sites offers a unique combination of in situ and remote sensing measurements capturing and documenting the variability of particulate and gaseous atmospheric composition, but also the optical, biochemical, and physical properties of aerosol particles, clouds, and precipitations. Given its location far away from any major emission sources, its altitude, and the mountain orography, the puy de Dôme station is ideally located to sample different air masses in the boundary layer or in the free troposphere depending on time of day and seasons. It is also an ideal place to study cloud properties with frequent presence of clouds at the top in fall and winter. As a result of the natural conditions prevailing at the site and of the very exhaustive instrumental deployment, scientific studies at the puy de Dôme strongly contribute to improving knowledge in atmospheric sciences, including the characterization of trends and variability, the understanding of complex and interconnected processes (microphysical, chemical, biological, chemical and dynamical), and the provision of reference information for climate/chemistry models. In this context, CO-PDD is a pilot site to conduct instrumental development inside its wind tunnel for testing liquid and ice cloud probes in natural conditions, or in situ systems to collect aerosol and cloud. This paper reviews 25 years (1995–2020) of atmospheric observation at the station and related scientific research contributing to atmospheric and climate science.

Classification of Clouds Sampled at the Puy de Dôme Station (France) Based on Chemical Measurements and Air Mass History Matrices

“…Biological and chemical analyses are performed in collaboration with the ICCF (Institute of Chemistry of Clermont-Ferrand). It is part of the French CO-PDD (Cézeaux-Aulnat-Opme-Puy De Dôme) multisite platform fully described by Baray et al [39] in terms of instrumentations and data availability and widely employed [22,25,[52][53][54][55].…”

“…A cluster of starting back trajectory points is defined by the user and advected by the model using a bilinear interpolation for horizontal wind fields and time and a log-linear interpolation for vertical wind fields. The CAT model has already been used to determine the air masses arriving in PUY on the basis of calculations of two sets of 24 h back trajectories per day over a two-year period (2015-2016) [39].…”

Insights into tropical cloud chemistry in Réunion (Indian Ocean): results from the BIO-MAÏDO campaign

“…Air mass backward trajectories are calculated with the CAT (Computing Atmospheric Trajectory Tool) model (Baray et al, 2020). A high-resolution version of CAT (MesoCAT) has been developed especially for the BIO-MAÏDO project (Rocco et al, 2021).…”

Atmospheric Rivers and Associated Precipitation over France and Western Europe: 1980–2020 Climatology and Case Study

“…ECMWF ERA5 data, used to detect AR and to provide the large scale dynamical description of the case study, were supplemented by observational ground based data performed in the framework of the Cézeaux-Aulnat-Opme-Puy de Dôme instrumented site [17] to estimate the local influence of AR on water vapor and precipitation near Clermont-Ferrand. The air masses arriving at Puy de Dôme (45.77 • N, 2.96 • E; 1465 m) originate mainly from the Atlantic Ocean (more than 50% in winter, more than 40% during the other seasons [17]). We used GPS series from the ground-based station at the Cézeaux site (45.76 • N, 3.11 • E, 410 m) and the rain estimations were made from disdrometer and rain gauge series at Opme (45.71 • N, 3.09 • E, 660 m).…”