In the west a lot of our weather is effected by the EPO/PNA phase. I don' t know much about EPO but I know when it is a + phase you get a 'raging' jet that blocks cold air from coming down. -PNA I think brings on more NW events.
Lately neither cannot go negative for very long though I think the PNA is negative but the atmospheric setup is having a hard time recoupling and the GFS weather model is crap about it.
~21 min - “A case for climate engineering” by David keith “20000 tons of sulfuric acid a year”. This isn’t weather modification but rather “solar radiation management”. Later they talk about barium and its concentrations.