Are there non-negligible negative effects from the charged particles/ radiation from watching auroras?
I assume you are talking about biological effects of radiation. I don’t think the act of watching auroras causes extra radiation damage to your body, but it is indeed true that one gets a higher radiation dose near the Earth’s poles, where solar particles tend to spiral in towards the surface. In practice it’s not too big a deal, and near the surface of the Earth one is shielded from radiation by the atmosphere. However, higher up above the surface of the Earth there is less atmospheric shielding, so astronauts and pilots who fly polar routes frequently do need to keep careful track of radiation dosage.
