HOLOCENE PALAEO-WATER TABLE RECONSTRUCTIONS FROM BRITAIN AND NORTH ATLANTIC CLIMATE VARIABILITY

Variability in the North Atlantic is presumed to be one of the main drivers of long term terrestrial climate change in mid-latitude oceanic Europe. However, there have been rather few attempts to make these links explicitly by compiling terrestrial records and comparing them with oceanic and ice core records. One key source of terrestrial data over the mid-late Holocene for Britain is peat surface wetness records. Peat surface wetness changes reflect variability between periods of relatively warm/dry to cool/wet conditions, although the precise relationship of surface wetness with precipitation and temperature is still unclear. Here we compile a series of records of palaeo-water table depth based on testate amoebae analysis from peatlands in northern Britain to identify key phases of climate change. On the basis of comparisons between high-resolution surface wetness records with instrumental climate data, these are interpreted as primarily reflecting changes in summer precipitation. We hypothesize that the long term changes in peatland palaeo-water table depth reflect low frequency variability in the dominant position and strength of zonal circulation during the summer months.