These weather modification programs have been going on for a long time, kept outside of public oversight by design.

Beyond observable data, like discrete on/off spraying vs "condensation trails", the levels of metals (aluminum, barium) that do not naturally occur in that form & shouldn't exist at any concentration in the atmosphere, and the effects of these aerosolized metals on living organisms (exponential uptick in neurodegenerative diseases in humans and other species & the corresponding insanely high levels of aluminum in the brains of the diseased), there is gov documentation of their programs (often outsourced to defense contractors & universities) & policies...I've put some below:

1) ICAS report to the executive office on climate engineering in 1966 (in response to the federal council tasking report to find out "which agencies are doing what"): https://www.geoengineeringwatch.org/documents/19680002906_1968002906.pdf

2) 15 USC Ch. 9A: WEATHER MODIFICATION ACTIVITIES OR ATTEMPTS; REPORTING REQUIREMENT in 1976: http://uscode.house.gov/view.xhtml?path=/prelim@title15/chapter9A&edition=prelim

Notably, in 330b (c) in the above code: "In carrying out the provisions of this section, the Secretary shall not disclose any information referred to in section 1905 of title 18 and is otherwise unavailable to the public, except that such information shall be disclosed— (1) to other Federal Government departments, agencies, and officials for official use upon request; (2) in any judicial proceeding under court order formulated to preserve the confidentiality of such information without impairing the proceeding; and (3) to the public if necessary to protect their health and safety."

So no public disclosure...unless the ecocidal & genocidal sociopaths knowingly & irreparably wrecking people's health & safety w/o their knowledge or consent decide its suddenly necessary to disclose their poisoning after the fact to "protect public health & safety".

3) Senate document here (highlighted key excerpts & link to the full 740 some page full doc at the end) from 1978: https://www.geoengineeringwatch.org/massive-us-senate-document-on-national-and-global-weather-modification/