Rainmaker's cavum signatures open new applications for glaciogenic cloud seeding, increase solar radiation at surface
Rainmaker has identified at least seven cavum signatures linked to its cloud seeding operations in Oregon. A cavum signature, different from the radar-based signatures detected in Alaska, looks like a “hole punch” in the cloud, visible to the naked eye and from space. It’s a visible sign that operations are working as expected — and opens up novel applications for Rainmaker’s technology in industries like aviation and solar energy.
A “cavum” (plural: cava) is a local perturbation in a cloud layer, created when seeded precipitation falls out of a cloud as rain or snow, leaving a hole behind. Rainmaker’s field operators first spot cava from the ground, as in this image from a launch site in Oregon:
Cava can also be detected via GOES-18 satellite imagery, consistent with the timing and location of Rainmaker’s drone-based seeding events. Our researchers tracked one cavum over its life cycle, showing a growth period (0–45 mins), peak visibility (20–40 mins), weakening (45–75 mins), and eventual disappearance. This life cycle aligns with our radar validation findings, further showing that Rainmaker’s operations can successfully enhance precipitation in target areas.
This is not the first time that cloud seeding has been shown to cause cloud deformation. Project Cirrus, a research campaign from the late 1940s, produced the famous “racetrack” image below, a large cloud-top trench produced by seeding aircraft on a rectangular flight track. This was early evidence of cloud seeding’s potential — potential that Rainmaker now fulfills.
WHY IT MATTERS
Cava are more than just passing weather phenomena. They point to new pathways for research and new industrial applications.
- Research applications: Cava indicate that drone seeding is highly efficient, producing full cloud glaciation by converting SLW into precipitation. By studying cases where they occur, Rainmaker can learn how to improve the effectiveness and yield of its seeding operations and gain a deeper understanding of underlying microphysical processes.
- Industrial applications: Facilities dependent on clear skies, such as airports and solar farms, could benefit from drone programs designed to create cava in fog or cloud layers, improving visibility and solar radiation at the ground. Fog and overcast conditions occur frequently in the winter, when glaciogenic cloud seeding is most effective. Rainmaker’s platform is lightweight, rapidly deployable, and capable of supporting facilities in remote or rural areas.