How useful could Arabic documentary sources be for reconstructing past climate?

Trees, corals, ice cores and documentary evidence provide high-resolution proxies that allow past climate to be reconstructed (Jones et al., 2009). Documentary evidence includes all forms of written historical information about past climate or weather, but its use for climate reconstruction is restricted to locations for which there is a rich documentary legacy. Several climate analyses and reconstructions have been undertaken using documentary evidence from Europe (Brázdil et al., 2005; 2010), North and South America (Dupigny-Giroux and Mock, 2009; Prieto and García-Herrera, 2009; Neukom et al., 2010), Asia (Ge et al., 2005; 2010; Aono and Kazui, 2008; Hirano and Mikami, 2008) and oceanic areas (García-Herrera et al., 2005). The Islamic World is a region for which such sources could also be used to reconstruct past climate, as indeed they have been widely used for astronomy and geophysics. Astronomers have used the observations made by Arab astronomers for centuries, with some remarkable examples. Historical eclipse observations, recorded by various ancient and mediaeval cultures including Arabs, have enabled changes in the Earth’s rate of rotation to be monitored with fair precision as far back as around 700 AD (Stephenson, 2003). Rada and Stephenson (1992) catalogued meteor showers using mediaeval Arab chronicles and Ahn (2003) investigated the spatial distribution of meteor streams crossing the orbit of the Earth from the tenth to the fourteenth centuries using chronicles from Korea, Japan, China, Arabia and Europe. Documentary sources from Iberia have been used to identify and date such astronomical phenomena as eclipses and comets (Vernet, 1982), naked-eye sunspots (Vaquero and Gallego, 2002) and aurora sightings (Vaquero and Gallego, 2001). The work of Basurah (2006) provides descriptions for 18 aurora displays on various dates at low latitudes in the Mediterranean area taken from Islamic chronicles (ninth to sixteenth centuries). In seismology, Arabic chronicles were extensively used to prepare the Seismic Catalogue of the Iberian Peninsula (Martínez and Mezcua, 2002) and to study seismic activity in Syria and Palestine (Ambraseseys, 2005). However, the use of these sources to recover climate information is, to the best of our knowledge, still very limited (Bulliet, 2009; Jones et al., 2009). Here we describe a preliminary inquiry based on Arabic documentary sources from Iraq. We would stress the antiquity of the documents used, with dates in the period 816–1009 AD. The sources consulted are Arabic chronicles that narrate the social, political and religious history of different regions in a form very characteristic of Arab culture.