This Scientific American article linked below about the same project reads, “The experiment is spraying microscopic salt particles into the air…” Note their misleading use of the word ‘microscopic’. 

Researcher Pete Ramón points out:

“Microscale can never be nanoscale in terms of measurement. When non-scientific authors use micro- to describe nano- they're wrong, but when scientists in the field use micro- to describe nano-, it's intentionally misleading/confusing the reader. That said, nanomaterials can be coagulated/agglomerated/grown to create micro-sized materials. Also, creating nanomaterials from micro can also be done via techniques such as ablation and sonication.”

Geoengineering Test Quietly Launches Salt Crystals into Atmosphere (2024)

​

This article linked below reads, “Developing a new cloud-aerosol research instrument for use in small-scale field studies. This new research instrument generates controlled volumes and sizes of tiny, sub-micrometer seawater particles in sufficient numbers to increase the local brightness of low clouds in a marine environment"

Researcher Pete Ramón points out their use of the word “sub-micrometer” means by definition that it is nanoscale. If it’s in the nanoscale, we are talking about nanoparticles. Specifically, nanoparticles being released into the sky.

Marine Cloud Brightening Program

​

Salt particles ranging in size from 30-100 nanometers are the most effective for spraying. 

“Factors determining the most efficient spray distribution for marine cloud brightening”