In 2001, Steve Pearse published a paper on space weather and extraterrestrial visitation. It is well known that UFO sightings often come in so-called flaps. in his paper, Pearse discovered, among other things, a correlation between solar cycles and UFO activity.

He has now updated his paper, including additional data for the 2001-2015 period.

You can read the 123 page PDF here.