Iraqi Sources from 9th and 10th Centuries Give New Meteorological
Insights
Ancient manuscripts written by Arabic scholars can provide valuable
meteorological information to help modern scientists reconstruct the
climate of the past, a new study has revealed. The research, published
in Weather,
analyses the writings of scholars, historians and diarists in Iraq
during the Islamic Golden Age between 816-1009 AD for evidence of
abnormal weather patterns.
Reconstructing climates from the past provides historical comparison to
modern weather events and valuable context for climate change. In the
natural world trees, ice cores and coral provide evidence of past
weather, but from human sources scientists are limited by the historical
information available. Until now researchers have relied on official
records detailing weather patterns including air
force reports during WW2 and 18th century ship’s logs.
Now a team of Spanish scientists from the University of Extremadura have
turned to Arabic documentary sources from the 9th and 10th centuries
(3rd and 4th in the Islamic calendar). The sources, from historians and
political commentators of the era, focus on the social and religious
events of the time, but do refer to abnormal weather events.
“Climate information recovered from these ancient sources mainly refers
to extreme events which impacted wider society such as droughts and
floods,” said lead author Dr Fernando Domínguez-Castro. “However, they
also document conditions which were rarely experienced in ancient
Baghdad such as hailstorms, the freezing of rivers or even cases of
snow.”
Baghdad was a centre for trade, commerce and science in the ancient
Islamic world. In 891 AD Berber geographer al-Ya'qubi wrote that the
city had no rival in the world, with hot summers and cold winters,
climatic conditions which favored strong agriculture.
While Baghdad was a cultural and scientific hub many ancient documents
have been lost to a history of invasions and civil strife. However, from
the surviving works of writers including al-Tabari (913 AD), Ibn
al-Athir (1233 AD) and al-Suyuti (1505 AD) some meteorological
information can be rescued.
When collated and analysed the manuscripts revealed an increase of cold
events in the first half of the 10th century. This included a
significant drop of temperatures during July 920 AD and three separate
recordings of snowfall in 908, 944 and 1007. In comparison the only
record of snow in modern Baghdad was in 2008, a unique experience in the
living memories of Iraqis.
“These signs of a sudden cold period confirm suggestions of a
temperature drop during the tenth century, immediately before the
Medieval Warm Period,” said Domínguez-Castro. “We believe the drop in
July 920 AD may have been linked to a great volcanic eruption but more
work would be necessary to confirm this idea.”
The team believes the sources show Iraq to have experienced a greater
frequency of significant climate events and severe cold weather than
today. While this study focused on Iraq it demonstrates the wider
potential for reconstructing the climate from an era before
meteorological instruments and formal records.
“Ancient Arabic documentary sources are a very useful tool for finding
eye witness descriptions which support the theories made by climate
models,” said Domínguez-Castro. “The ability to reconstruct past
climates provides us with useful historical context for understanding
our own climate. We hope this potential will encourage Arabic historians
and climatologists to work together to increase the climate data rescued
from across the Islamic world.”
