Analysis of early instrumental air temperature observations before and after the Tambora volcano eruption

The study analyzes the recently summarized data on surface air temperature in the east of North America, in Western and Eastern Europe, and in India before and after the Tambora volcano eruption occurred in Indonesia in 1815. The well-known fact is proved that no cooling occurred after the Tambora eruption in the east of Europe and in India. It is found that the insignificant (at the decadal timescale) cooling was observed in all analyzed regions: it started earlier than the Tambora eruption and than the stronger eruption of another volcano in 1809. The paper demonstrates that it is impossible to reveal cause-effect relations between the general cooling and the eruption of the above volcanoes based on the available data on surface air temperature. Cold snaps that follow the later volcanic eruptions were identified by meteorologists using the data of the whole network of meteorological observations established in the second half of the 19th century. However, these cold snaps cannot be detected using data on surface air temperature only.