Alexander Buchan (meteorologist)

Alexander Buchan (24 April 1829 – 6 May 1907) was a Scottish meteorologist, oceanographer, and botanist. He is best known for his contributions to the study of weather patterns and his pioneering work in the field of climatology, particularly his identification of recurring weather anomalies now known as Buchan spells.

Buchan served as Secretary of the Scottish Meteorological Society from 1860 until his death. He played a vital role in establishing and maintaining a network of weather observation stations across Scotland, collecting and analyzing data to gain a better understanding of regional and global weather systems.

His most significant work is considered to be "Handy Book of Meteorology" (1867), a comprehensive textbook that became a standard reference for meteorologists and students for many years. The book covered a wide range of topics, including atmospheric physics, weather forecasting, and the distribution of climate zones.

Buchan's analysis of long-term temperature records led him to identify periods of abnormally warm or cold weather that tended to recur around the same dates each year. These recurring temperature fluctuations, dubbed "Buchan spells" or "singularities," were initially met with skepticism but are now recognized as statistically significant features of the Northern Hemisphere's annual temperature cycle. Examples include warm spells around December 3-16 and cold spells around April 11-14 and August 6-12. While the exact causes of these spells are complex and not fully understood, they are believed to be related to large-scale atmospheric patterns and ocean-atmosphere interactions.

Beyond meteorology, Buchan also made contributions to oceanography, studying sea surface temperatures and ocean currents. He also held an interest in botany and the distribution of plant species. His contributions to the understanding of weather and climate cemented his place as a leading figure in 19th-century meteorology.