Detalles de publicación
PP 06057
On the connection between solar activity and low-latitude aurorae in the period 1715-1860
(1) Instituto de Astrofísica de Canarias
(2) Departamento Fisica, Universidad de Extremadura, Cáceres
(3) Observatorio del Ebro, CSIC- Univ. Ramón Llull, Roquetes
Observations of aurorae borealis at low latitudes are very rare,
and are clearly associated with strong geomagnetic storms.
Morphologically, they are characterized by a diffuse red colour
with no rapid motions. The main aim of this paper is to analyse two hitherto ignored aurorae that were observed at two low latitude sites, Tenerife (28$^{\circ}$N 18$^{\circ}$W) and Mexico City (19$^{\circ}$N 99$^{\circ}$W), in 1770 and 1789, respectively. These observations can give supplementary information about the level of solar activity at those times where direct solar
observations were rather scarce. Studying also the behaviour of the heliosphere during this period using different proxies, we find that the open magnetic
field better describes auroral occurrences. The variation over time in geomagnetic latitude at the two sites is also calculated.
and are clearly associated with strong geomagnetic storms.
Morphologically, they are characterized by a diffuse red colour
with no rapid motions. The main aim of this paper is to analyse two hitherto ignored aurorae that were observed at two low latitude sites, Tenerife (28$^{\circ}$N 18$^{\circ}$W) and Mexico City (19$^{\circ}$N 99$^{\circ}$W), in 1770 and 1789, respectively. These observations can give supplementary information about the level of solar activity at those times where direct solar
observations were rather scarce. Studying also the behaviour of the heliosphere during this period using different proxies, we find that the open magnetic
field better describes auroral occurrences. The variation over time in geomagnetic latitude at the two sites is also calculated.