Built to close a long-standing gap
in cloud measurement.
RepliClouds was founded to close a measurement gap the atmospheric science community had long worked around — and to replace it with an instrument that is honest about the conditions inside a real cloud.
Why the particles you can't see shape the weather you experience.
Every cloud starts with something invisible — and measuring it accurately is one of the clearest ways to sharpen our picture of how the climate is changing.
Those particles — sea spray, dust, or smoke — are too small to see, but water vapour condenses on them to form a droplet. These seeds are called cloud condensation nuclei, and without them, clouds would not form in our atmosphere.
Measuring them accurately matters because the way these particles interact with clouds is the single largest source of uncertainty in climate projections. Such measurements need to mimic real atmospheric conditions as closely as possible, which instruments of the conventional design cannot do. The HCCNC, developed at the Atmospheric Physics Group at ETH Zurich, measures closer to the conditions under which clouds actually form.
Better knowledge of the cloud-forming capabilities of these particles can improve cloud and climate models — which matters, because clouds shape much of what we experience: rainfall, drought, storms, and the timing of the monsoon.
From instrument-level measurement to long-term climate planning.
Three kinds of impact, from one instrument.
Scientific Precision
The HCCNC is engineered to access larger measurement ranges than available instruments, providing data the scientific community needs to address the largest remaining source of climate uncertainty.
Social Equity
Deploying the HCCNC in field campaigns that obtain critical data in climate-vulnerable regions builds the observational foundation that long-term resilience planning depends on.
Environmental Responsibility
The core of each HCCNC (its plates) is manufactured by selective laser melting (3D printing), a metal additive process that wastes under 1 % of material — compared with up to 90 % for conventional CNC machining.
"To build instruments that make the atmosphere legible — so that science, and the world it serves, can see clearly."