Arabic chronicles Shed Light on weather of yore

Baghdad winters just aren't what they used to be, Spanish researchers find.

By DAVID ROSENBERG / THE MEDIA LINE
Snow falls in Baghdad in 2008 390 (R) (photo credit: Mahmoud Raouf Mahmoud / Reuters)
Snow falls in Baghdad in 2008 390 (R)
(photo credit: Mahmoud Raouf Mahmoud / Reuters)
A gentle sprinkling of snow fell on Baghdad in the first days of 2008, a bare wisp that mostly melted when it touched the ground yet it was the first and only snowfall in about a century. But in the early Middle Ages, when the city was the commercial and cultural capital of the Muslim world, the white stuff came more often, with snowfalls recorded in 908, 944 and 1007.
The more frequent snow – as well as freak temperature drops during Baghdad’s usually sweltering July back in 920 – is among the tantalizing weather data that a team of scientists discovered after pouring through historical records of the era. It’s not that the city and its environs were necessarily colder and wetter back then but the weather appears to have been more erratic.
“We found that some extreme events like snowfalls in Baghdad were more frequent during the period 900-950 than nowadays. But we cannot conclude that this period in mean was colder than today,” Fernando Domínguez-Castro, who led the team of researchers, told The Media Line in an e-mailed response to questions.
Studying medieval weather patterns isn’t for curiosity’s sake. Assembling data on changes in temperature and perception give meteorologists and climatologists more insight into modern weather, in particular a better perspective on global warming. Historical data can provide clues as to whether today’s trends mirror cyclical patterns or represent a new phenomenon, perhaps induced by human activity.
As Bob Dylan said, you don't need a weatherman to know which way the wind blows.
The team led by Domínguez-Castro, who teaches at Spain’s Universidad de Extremadura, gathered their information on the weather of yore by systematically reading through medieval chroniclers such as Muhammad ibn Jarir Al-Tabari  (838–923), Ali Ibn Al-Athir (1233–1160) and Jalaluddin Al-Suyuti (1445–1505). That meant assembling a multidisciplinary team of climatologists like Domínguez-Castro, meteorologists, Arabic translators and historians.
In Europe, weather historians usually turn to official archives, which are regular and continuous. In the Middle East, those kinds of records have often been destroyed – Baghdad, for instance, was sacked in 1258 by Genghis Khan’s grandson, Hulegu – forcing researchers to turn to independent sources that survived extant or were copied by later historians like Al-Suyuti in the case of Domínguez-Castro study.
“These kinds of studies are really important because now we start to have a picture of the climate in this epoch,” Domínguez-Castro said. “Now, we know a little more about the climate in Baghdad in these times. And more important, we know that it’s possible to rescue climatic information from Arabic chronicles. Many of this chronicles remain unexploited.”
These independent writers were historians, more concerned about caliphs and court intrigue than climate. But they did take an interest in the weather, especially when it was unusual or affected agriculture.
“On December 7, there was a great snowfall in Baghdad. Six days before that, the weather had become very cold, and after the snow, it was even more cold,”  IbnAl-Jawzi recorded in his Categorical Collection of the History of the Nations about the year 926. “The scholar known as Abu Zakariya sat in the middle of the Tigris, on the ice, and gave there lessons of Prophetical tradition.”
Indeed, the wealth of information waiting to be prized out of those medieval texts is so important and vast that the German Science Foundation has launched a project called Historical Climatology of the Middle East Based on Arabic Sources Since 800 AD (Domínguez-Castro’s work is not connected with it).
“The large body of written historical sources from Islamic medieval times shows great potential and perspective for climate reconstructions in the Middle East during the Medieval Climate Anomaly,” Steffen Vogt, who teaches in the Department of Physical Geography at Germany’s Albert-Ludwigs-University of Freiburg, wrote in a  paper on the subject last year.
Medieval Climatic Anomaly?
That’s the name scientists give to the period of the unusually warm climate in the North Atlantic region that lasted from about 950 to 1250. The fact is, however, that while it was hot in Europe and North America, other parts of the world were cooler than their norm. So, while Vikings were getting autumn tans, Baghdadis were throwing snowballs at each other once every couple of decades.
Domínguez-Castro said the drop in temperatures during July 920 may have been linked to a great volcanic eruption.
The data for world climate before the modern period when professional meteorologists began collecting systematical records is poor. As a result, historians of the weather usually rely on indirect evidence in the form of tree rings, ice cores and coral, but that kind of information lacks details like freak storms and floods.
Human sources only cover certain times and places so for instance European chronicles while more complete go back typically no further than 1500, according to Vogt. In the medieval Arab world, the trend line is the reverse and the quantity of manuscript information on the weather begins to tail off as writers turned the attention away from accounts of events and more toward biographies and anecdotes.
There is another problem. The amount of material changes by time and place, depending on the rise and fall of various cities as scientific and cultural centers in the region. Between the ninth and 15th centuries, the core of documentary evidence shifts from Abbasid Baghdad to Ayyubid centers in modern day Syria and Israel, and later to Fatimid and Mamluk Egypt.
Vogt and his team surveyed about 50 medieval Arabic manuscripts, including such well know works as Al-Tabari’s History of Prophets and Kings as well as a host of lesser-known works,  like the diary of Ibn Tawq, a Damascus notary of late 15th century.
Domínguez-Castro said he is now turning his sights to Spanish-Arabic documentation in his homeland.