One of the key components of the CAINA campaign has begun at the northern measurement site in Lutjewad: airborne cloud observations using the ACTOS platform, operated by Leibniz Institute for Tropospheric Research (TROPOS). ACTOS is mounted beneath a low-flying helicopter and collects data directly from within and around cloud layers, offering researchers a rare opportunity to observe cloud processes as they happen.
These measurements focus on the internal structure and dynamics of clouds — including droplet size and number, aerosol concentrations, humidity, temperature and air turbulence. This allows researchers to study how nitrogen pollution changes the way clouds form, evolve and interact with solar radiation. Early findings suggest that nitrogen emissions may reduce cloud reflectivity and alter cloud lifetimes, with consequences for climate feedbacks and weather systems.
What makes these in-cloud observations particularly valuable is the ability to connect them with continuous data collected by the Ruisdael Observatory. At both Cabauw and Lutjewad, fixed instruments have been monitoring the Dutch atmosphere over long timescales. This broader measurement framework provides
essential context, helping researchers interpret short-term campaign data more accurately and place it within evolving atmospheric patterns.
The CAINA campaign will continue throughout April, combining ground-based, airborne and laboratory measurements. In the weeks ahead, more updates will follow from the field — including perspectives from researchers and further insight into how pollution influences the skies above the Netherlands.
📍 More information
To follow the CAINA campaign and learn more about the partner institutes and measurement platforms involved, visit: CAINA Project – News or our website.
