Fernando Dominguez-Castro of the University of Extremadura (Spain) and his colleagues raised the documents written in Baghdad 816-1009, respectively, during the "Golden Age" of Muslim culture.
This is one of the few sets of written sources, provides a glimpse into the past climate, where weather conditions were recorded only in some places, or not recorded at all. This is a most valuable addition to the data generated through the core of rock, sediment and ice, as well as corals and tree rings. Until now, researchers have relied largely on official papers — XVIII century ship logs and reports of the Air Force World War II. At this time, attention is paid to the diaries, letters, etc.
The more informal sources, the more confidence we can say that if it mentioned the weather, we are talking about something extreme and unusual. No exception, and this body of documents. They report that in the IX-X centuries near Baghdad visited hail, freezing rivers and even occasionally snowing.
Cold significantly increased in the beginning of X century. For example, in July 920, the outstanding features of the cold — perhaps as a result of the eruption of some volcano. Snow covered Baghdad in 908, 944 and 1007, respectively. In the memory of the people living in these places today, the snow was only in 2008.
Baghdad was the center of commerce and science of medieval Islam. In 891, the Berber geographer Yacoubi said that the city has no equal in the world. Hot summer, cold winter — what do you need agricultural productivity!
The study is published in the journal Weather.
On materials: AlphaGalileo