Caribbean sea surface temperatures: two-to-three degrees cooler than present during the Little Ice Age

We determined the seasonal environmental conditions during the Little Ice A ge (LIA) by interpreting isotope proxies in the coral skeleton of Mantastre a faveolata from the northeast Caribbean. The oxygen isotope composition wa s determined for three time intervals during the LIA. (1700-1705, 1780-1785 , 1810-1815), thought to correspond to the coldest intervals. The period 19 84-1989 was used to represent modern calibration conditions. We determined that SSTs from the LIA intervals are nearly 2-3 degreesC cooler than presen t. LIA cooling in the Caribbean may have resulted from regional oceanic and atmospheric circulation differences, especially in winter. We propose that a trough of cold air from the north Atlantic may have extended farther sou th than present, into the northern Caribbean. Although there are indication s from Pacific corals that seasonality was greater during the LIA, this doe s not seem to be the case for the Caribbean.