Long-Term Variability of Temperature and 14C in the Gulf Stream: Oceanographic Implications

Abstract

Variability in temperature and 14C levels are recorded in coralline aragonite that grew in the Gulf Stream during the past four centuries. In particular, 18O/16O ratios reflect a decrease of ca 1 degree C in surface water temperature during the latter part of the Little Ice age. 14C levels also rose in the surface waters of the Gulf Stream and in atmospheric CO2 during the Maunder minimum. These observations indicate that ocean circulation may have been significantly different in the North Atlantic around the beginning of the 18th century.