Period analysis of acoustic backscatter data.

• Main Authors: Jonathan H. Cohen (7958483), Kim S. Last (11581392), Corie L. Charpentier (3200505), Finlo Cottier (749186), Malin Daase (471602), Laura Hobbs (9152223), Geir Johnsen (257802), Jørgen Berge (235355)
• Format: Other Non-Article Part of Journal/Newspaper
• Language: unknown
• Published: 2021
• Subjects: Physiology; Ecology; Inorganic Chemistry; Environmental Sciences not elsewhere classified; Astronomical and Space Sciences not elsewhere classified; Biological Sciences not elsewhere classified; thysanoessa inermis </; therefore question whether; main migratory species; acoustic field observations; 81 ° n; 5 ° n; arctic ocean extends; light measurements demonstrate; characterize light across; weak midday twilight; div >< p; arctic krill (<; arctic polar night; arctic krill; light plays; polar night; zooplankton community; using electroretinogram; traditional definitions; sun ’; subjective night; photophysiological cycles; north pole; midnight sun; maximum extent; lower latitudes; latitudinal gradient; high latitudes; fundamental role; darkest parts; constant darkness; circadian clock; auroral components; although differences; Arctic; Arctic Ocean; North Pole; Rijpfjorden; Arctic krill; Kongsfjord*; Kongsfjorden; Rijpfjord*; Zooplankton; Thysanoessa inermis
• Online Access: https://doi.org/10.1371/journal.pbio.3001413.s003

Period (hours) estimates for Kongsfjorden and Rijpfjorden acoustic data (from Fig 2 ) are provided for discrete depths throughout the water column for January 2018. Periodicity was calculated by Lomb–Scargle periodogram. Gray shading indicates periods within the circadian range (20–28 hours), showin...