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

Abstract

Variability in temperature and 14 C levels are recorded in coralline aragonite that grew in the Gulf Stream during the past four centuries. In particular, 18 O/ 16 O ratios reflect a decrease of ca 1°C in surface water temperature during the latter part of the Little Ice age. 14 C levels also rose in the surface waters of the Gulf Stream and in atmospheric CO 2 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.