Founded by Professor Henri Dessens in the 1960s with the support of the CNRS, the Centre de Recherches Atmosphériques (CRA—Atmospheric Research Center) was established to provide experimental facilities for the atmospheric physics community. The CRA brings together observation resources and measurement campaign infrastructure, while also offering educational support for fieldwork training. Since 1983, following the creation of the Laboratoire d’Aérologie (Aerology Laboratory), it has been affiliated with Toulouse institutions. Today, it operates under the University of Toulouse and is managed by the Observatoire Midi-Pyrénées.
The CRA is located near the town of Lannemezan (Hautes-Pyrénées), on the plateau of the same name, at an altitude of 600 meters. Covering 70 hectares, the site is surrounded by meadows, crops, and forests. Its unique location—flat and open—makes it ideal for in-situ and remote-sensing atmospheric measurements, while also allowing the observation of mountain-related meteorological phenomena that strongly influence the local climate. Additionally, it facilitates the study of interactions between the surface (vegetation, biosphere, land use) and the atmosphere.
The CRA is one of France’s five national “multi-instrumented” sites dedicated to atmospheric observation. It brings together a wide range of complementary instruments in one location, enabling dense and comprehensive monitoring of the atmosphere.
Instrumented sites in France each have their own unique characteristics in terms of environment and expertise. The CRA stands out in particular through:
- Its 60-meter instrumented mast, the only one of its kind in France, equipped with around thirty sensors for in-situ meteorological measurements, greenhouse gases, and energy exchanges between the surface and the atmosphere.
- The measurement of vertical wind and turbulence profiles using radar, which are integrated into France’s national weather forecasting models and those of other European countries.
- The measurement of atmospheric electricity from transient luminous events (such as “sprites,” “elves,” and “jets”) that occur above thunderstorms.
Observation site
The CRA is linked with the Pic du Midi Environmental Platform to form the Pyrenean Platform for Atmospheric Observation (P2OA). Both are designated by INSU (Institut National des Sciences de l’Univers, part of CNRS) for their role as a climate observatory and a hub for experimental research. This collaboration enables the study of exchanges and transport of chemical compounds, dust, and other elements between the plains and mountains, as well as between the lower and higher layers of the atmosphere.
Within the P2OA framework, the CRA site is one of the cornerstones of the national research infrastructure Aerosol, Cloud, and Trace Gases Research Infrastructure (ACTRIS-Fr). Following a proposal by the French Ministry of Education and Research in 2021, it will receive the label of the European infrastructure ACTRIS-EU, gaining recognition at the European level.
The long-term observations conducted at the CRA contribute to 7 national and international networks for real-time meteorological monitoring and climatological tracking. Meteorological stations from various institutions, including Météo-France, have been hosted on the site since 1989.
These stations contribute to weather forecasting, climate monitoring, and hydroelectric dam management. Additionally, the vertical wind profiles measured at the CRA are integrated into European weather forecasting models. The CRA also plays a role in observing and disseminating greenhouse gas data to support climate change monitoring(as part of the ICOS infrastructure).
The CRA maintains a highly open data-sharing policy, providing easy access to its observations through the P2OA database and the national atmospheric data hub AERIS. It also participates in the national project “ReOBS”, which compiles key climate variables into a standardized format and a single file with a shared time scale.
Realtime monitoring of CRA observations
VHF wind profiler radar data, which measures wind between 1.5 and 16 km in altitude.
UHF wind profiler radar data, which measures wind between 150 meters and 3–7 km in altitude, depending on humidity conditions.
Images from the RAPACE total-sky imager, which captures a visible-light photo of the sky by pointing at the zenith.
Experimental site
Since 2010, the CRA has regularly hosted research campaigns led by various groups. Thanks to its continuous measurement instruments—used as benchmarks for testing new sensors—its highly suitable infrastructure, expansive space, and dedicated staff, the site is exceptionally well-suited for accommodating experiments.
The CRA plays a key role as a support site for pre-campaigns involving drones or balloons for Toulouse-based laboratories such as LAERO, the National Center for Meteorological Research (CNRM), and the French Civil Aviation University (ENAC). These preparatory campaigns are essential for national and international programs.
Academic training site
Hosting training programs at the CRA is one of the site’s key strengths: practical fieldwork sessions, organized as micro-campaigns, are offered for undergraduate and master’s university programs. These sessions leverage the site’s infrastructure, instruments, and expertise. The CRA thus provides students with their first hands-on research and experimentation experience.
The CRA welcomes students from master’s and bachelor’s programs at institutions such as UT3 Paul Sabatier, the University of Pau and the Adour Region, the University of Versailles Saint-Quentin, the French National School of Meteorology (École Nationale de la Météorologie), and the École Normale.
