A relatively compact beam of EM energy might be an attempt to disrupt communications in NY. However, high frequency EM radiation would not be visible. We can’t see beyond the violet end of the spectrum this is white light.
?...Would a relatively compact beam of EM cause molecules (air or pollution) in the atmosphere to vibrate and emit light? I can’t answer that question. Any Physics teachers out there?
You would need to better define where on the EM scale you are asking about. Radio frequencies (https://en.wikipedia.org/wiki/Radio_frequency) can and do ionize the atmosphere but it takes a great deal of power and typically doesn’t go far from the antenna. I have seen plasmas form in atmosphere briefly during experiments.