Fig. 3
From: South American auroral reports during the Carrington storm
Dipole field lines that could represent the auroral display observed at S33° 28′, W70° 41′. The red lines, which could manifest the reddish aurora, are the field lines ranging between L = 1.21 and 1.30 (24.6° and 28.7°) in the left panel, and those ranging between L = 1.23–1.30 (25.6° and 28.7° ILAT) with heights ranging from 220 km to 400 km. They are constrained by the constellations observed at 2.5 LMT on 2 September 1859 (Diaz’s report) or by the auroral edge at the western horizon (Huidobro’s report). In both cases, these red lines span from − 20.0° to − 2.5° in the magnetic longitude (MLON). The purple lines (that could manifest the purple transparent gauze”) range between L = 1.29 and 1.60 (28.3° and 37.8° ILAT) with the same height as the red lines, span from − 5.0° to − 0.5°