• PDM: 42.936°N 0.142°E 2877 m a.s.l.
• CRA: 43.129°N 0.367°E 600 m a.s.l.

Observational platform

France

• French National Centre for Scientific Research (CNRS)
• Université Toulouse III - Paul Sabatier (UT3)

https://p2oa.aeris-data.fr/

• Francois Gheusi
  Facility PI
• Véronique PONT
  PI deputy
• Marie LOTHON
  Facility PI

The « Centre de Recherches Atmosphériques » (CRA) is a rural observatory for atmospheric sciences, extending over 70 ha of pasture prairies. The site is located on a relatively flat small plateau in the northern foothills of the Pyrenes, about 28 km north-east of the Pic du Midi. The closest Pyrenean valley exit is 10 km south, and the influence of the valley drainage flow is frequent at night. Meteorological and energy flux, as well as GHG concentrations are measured at different levels of a 60-m instrumented mast. Among many other permanent measurements: 2 radars (UHF and VHF) measuring wind profile from 150 m to 16 km agl, a sky camera, and a ceilometer.
Pic du Midi (PDM) is a high-altitude observatory on top of an isolated summit in the Pyrenees, situated 20 km north of the Pyrenean main divide. Permanent monitoring of ambiant air is conducted for GHG, reactive gases, radon, and aerosol particles (including radionuclides).

The scientific activity at P2OA cover six main topics :
T1 : Atmospheric physico-chemistry at large scale, and climatic impact
T2 : Surface/atmosphère interactions, energy fluxes
T3 : Meteorology and boundary layer in complex terrain, influence on atmospheric composition
T4 : Atmospheric Electricity and Ionosphere
T5 : Geochemical cycles in the environment
T6 : Ionizing radiation in the environement
The scientific focus at CRA is mainly on surface / atmosphere exchanges and turbulence in the boundary layer. The site is particularly well suited to operate light unmanned air vehicles and balloons. Measurements at PDM focus mainly on free-tropospheric composition. Both sites can be used in synergy to study atmospheric exchanges between the plain and the mountains. The VHF wind profiler at CRA provides a regional reference point for synoptic wind.

• Lothon et al. (2024). The Pyrenean Platform for Observation of the Atmosphere: site, long-term dataset, and science. Atmos. Meas. Tech., 17(20), 6265-6300. https://doi.org/10.5194/amt-17-6265-2024
• Gueffier et al. (2024). Weather regimes and the related atmospheric composition at a Pyrenean observatory characterized by hierarchical clustering of a 5-year data set. Atmos. Chem. Phys., 24(1), 287-316. https://doi.org/10.5194/acp-24-287-2024