Detalles de publicación
PP 016004
Long-term trends and Gleissberg cycles in aurora borealis records (1600--2015)
(1)Instituto de Astrofísica de Canarias, 38200 La Laguna, Spain.
(2) Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Spain.\\
(3) Departamento de Física, Universidad de Extremadura, Avda. Santa Teresa de Jornet 38, 06800, Mérida, Spain.
(4) Departamento de Física, Universidad de Extremadura, 06071 Badajoz, Spain
The long-term spatial and temporal variation of
aurora borealis events from 1600 to the present were
studied using catalogues and other records of these
phenomena. Geographic and geomagnetic coordinates were
assigned to approximately 45000 auroral events
with more than 160000 observations. They were
analysed separately for three large-scale areas: (i)
Europe and North Africa, (ii) North America, and (iii)
Asia. Variations in the cumulative numbers of auroral
events with latitude (in both geographic and geomagnetic
coordinates) were used to discriminate between the two
main solar sources: coronal mass ejections and high-speed
streams from coronal holes. We find significant long-term
variations in the space-time distribution of auroras. We
mainly identify these with four Gleissberg solar activity
cycles whose overall characteristics we examine.
The Asian observations are crucial in this
context, and therefore merit further studies and
verifications.
aurora borealis events from 1600 to the present were
studied using catalogues and other records of these
phenomena. Geographic and geomagnetic coordinates were
assigned to approximately 45000 auroral events
with more than 160000 observations. They were
analysed separately for three large-scale areas: (i)
Europe and North Africa, (ii) North America, and (iii)
Asia. Variations in the cumulative numbers of auroral
events with latitude (in both geographic and geomagnetic
coordinates) were used to discriminate between the two
main solar sources: coronal mass ejections and high-speed
streams from coronal holes. We find significant long-term
variations in the space-time distribution of auroras. We
mainly identify these with four Gleissberg solar activity
cycles whose overall characteristics we examine.
The Asian observations are crucial in this
context, and therefore merit further studies and
verifications.