"Results from a 335-year oxygen isotope record (1657–1992) from a New Caledonia coral indicating that as many as 16 interannual-scale cooling events occur within 1 year of a volcanic eruption as determined by ice core records."
The ice core evidence discussed in this paper suggests a volcanic eruption in the tropics in 1809, as well as two distinct eruptions in North America around the same time.
This article examines the sequence of volcanic eruptions that occurred in the first half of the 19th century: in 1808-09, 1815, the 1820s, and the 1830s.
This article examines eyewitness reports of an atmospheric haze over parts of South America in December 1808. It also reprints the text of these accounts.
"A new data set of global marine air temperature data for the years 1807–1827 is used to show the impact of volcanic eruptions in ∼ 1809 (unlocated) and 1815 (Tambora, Indonesia)."
Wentworth
Institute of Technology