Text #3386"Cloudy and clear stratospheres before A.D. 1000 inferred from written sources". Journal of Geophysical Research .
The Sun seemed to be redder than usual, like the color of blood, in 212, and appeared red throughout the day when skies were clear, in 200, as seen from parts of central Italy (Livy 25.7.8., 31.12.5). Forsyth [1990b] has previously pointed out the Italian report of a halo-corona complex around the Sun in 203 (Livy 30.2.12). Babylonian observers, too, reported a halo around the Sun in 203, but such reports are very common there [Sachs and Hunger, 1989]. For three months during the year 208, stars were invisible from northern China [Pang et al., 1987]. In addition, there was a pronounced cooling at high latitudes during the years 208–204, as indicated by northern tree ring data [Baillie and Munro, 1988; Baillie, 1995]. All of these phenomena can be invoked as evidence for a recurrent or a prolonged volcanic dry fog, just as Hammer et al.  first proposed on the basis of a strong acidity peak in the Camp Century, Green- land ice core, dated at 210 ± 30. However, other Greenland ice cores, although better dated, do not show such a peak, or at least a strong one [Zielinski et al., 1994; Clausen et al., 1997]. Perhaps the eruptions were only of modest size. The historical data seem to suggest that at least two eruptions occurred between 212 and 200.