Didier Ricard | Searcharxiv

arXiv2026

The TEAMx Observational Campaign

As part of the international research programme TEAMx (multi-scale transport and exchange processes in the atmosphere over mountains - programme and experiment) a one-year long measurement campaign, the TEAMx Observational Campaign (TOC), was conducted between 2024 and 2025 in a north-south transect through the Alps. Building on the dense operational measurement network in the Alps, the TOC was designed to collect long-term atmospheric observations over the highly complex Alpine terrain. During two six-week long Extended Observational Periods, more than 40 research institutions came together to instrument about 30 sites in the four target areas of the TEAMx domain and study different transport processes, from gravity waves to orographic convection, thermally driven flows, and turbulent exchange. In addition to a suite of ground-based in-situ and remote-sensing instruments, observational activities included airborne measurements with up to three research aircraft and multiple UAS. This paper gives an overview of the science goals and the TOC design, together with preliminary analyses that highlight the potential of the collected dataset.

physics.ao-ph↗

arXiv2022

C3IEL: Cluster for Cloud Evolution, ClImatE and Lightning

Clouds play a major role in Earth's energy budget and hydrological cycle. Clouds dynamical structure and mixing with the ambient air have a large impact on their vertical mass and energy fluxes and on precipitation. Most of the cloud evolution and mixing occurs at scales smaller than presently observable from geostationary orbit, which is less than 1 km. A satellite mission is planned for bridging this gap, named "Cluster for Cloud evolution, ClImatE and Lightning" (C3IEL). The mission is a collaboration between the Israeli (ISA) and French (CNES) space agencies, which is presently at the end of its Phase A. The planned mission will be constituted of a constellation of 2 to 3 nanosatellites in a sun synchronous early afternoon polar orbit, which will take multi-stereoscopic images of the field of view during an overpass. C3IEL will carry 3 instruments: (1) CLOUD visible imager at a spatial resolution of 20 m. The multi-stereoscopic reconstruction of the evolution of cloud envelops at a resolution better than 100 m and velocity of few m/s will provide an unprecedented information on the clouds dynamics and evolution. (2) WATER VAPOR imagers at 3 wavebands with different vapor absorption will provide vertically integrated water vapor around the cloud and possibly a 3-dimensional structure of the vapor around the clouds due to their mixing and evaporation with the ambient air. (3) Lightning Optical Imagers and Photometers (LOIP). The lightning sensors will provide a link between cloud dynamics and electrification at higher spatial resolution than previously available. C3IEL will provide presently missing observational evidence for the role of clouds at sub-km scale in redistributing the energy and water in the atmosphere, and of the relation between storm vigor and frequency of lightning activity.

astro-ph.IM↗