COMPLEXITY OF HOLOCENE CLIMATE AS RECONSTRUCTED FROM A GREENLAND ICE CORE

Glaciochemical time series developed from Summit, Greenland, indicate that the chemical composition of the atmosphere was dynamic during the Holocene epoch. Concentrations of sea salt and terrestrial dusts incr eased in Summit snow during the periods 0 to 600, 2400 to 3100, 5000 t o 6100, 7800 to 8800, and more than 11,300 years ago. The most recent increase, and also the most abrupt, coincides with the Little Ice Age. These changes imply that either the north polar vortex expanded or th e meridional air flow intensified during these periods, and that tempe ratures in the mid to high northern latitudes were potentially the col dest since the Younger Dryas event.