The Medieval Climate Anomoly in the Iberian Peninsula reconstructed from marine and lake records
By Ana Moreno, et al.
Quaternary Science Reviews, Volume 43, 2012
Abstract: Selected multi-proxy and accurately dated marine and terrestrial records covering the past 2000 years in the Iberian Peninsula (IP) facilitated a comprehensive regional paleoclimate reconstruction for the Medieval Climate Anomaly (MCA: 900-1300 AD). The sequences enabled an integrated approach to land-sea comparisons and, despite local differences and some minor chronological inconsistencies, presented clear evidence that the MCA was a dry period in the Mediterranean IP.
It was a period characterized by decreased lake levels, more xerophytic and heliophytic vegetation, a low frequency of floods, major Saharan eolian fluxes, and less fluvial input ot marine basins. In contrast, reconstruction based on sequences from the Atlantic Ocean side of the peninsula indicated increased humidity.
The data highlight the unique characteristics of the MCA relative to earlier (the Dark Ages, DA: ca 500-900 years AD) and subsequent (the Little Ica Age, LIA: 1300-1850 years AD) colder periods. The reconstruction supports the hypothesis of Trouet et al. (2009), that a persistent positive mode of the North Atlantic Oscillation (NAO) dominated the MCA.
Introduction: The combination of proxy records from several paleoclimate archives (including tree rings, lake sediments, marine cores and speleothems) has enabled identification of five climatic periods during the last two millennia. These have been characterized in terms of temperature and precipitation variability (Mann and Jones, 2003, and include: the Roman Warm Period (RWP: 0-500 years AD), the Dark Ages (DA: 500-900 AD), the Medieval Warm Period (MWP: 900-1300 AD), the Little Ice Age (LIA: 1300-1850 AD), and a subsequent period of warming.
Thus, the MWP, which is also termed the Medieval Climate Anomaly (MCA) because of its large heterogeneity in space and time, is the most recent pre-industrial warm era in European climatology (Mann, et al., 2009).