On the relationship between coral δ 13 C and Caribbean climate

A coral ( Orbicella faveolata ) δ 13 C isotope ratio record off the southwest coast of Puerto Rico is used to indicate regional ocean–atmosphere conditions over the 20th century. The coral δ 13 C record is correlated positively with North Atlantic sea surface temperature (SST) and local evaporation. Spatial correlation maps show a broad area of influence by SST, sea‐level pressure and evaporation to the northeast of Puerto Rico. The composite maps reflect a strengthening of the North Atlantic anticyclone and east Pacific counter‐currents during years of enhanced coral growth. The coral δ 13 C record presented here corresponds with a local cloud cover increase of ~10% in parallel with a 0.5 °C rise of local SST since 1900. Environmental conditions tend to lead coral growth in a knock‐on effect as seen in local SST, cloud cover and evaporation data. The coral community may thus be a sentinel of both multi‐year fluctuations and centennial trends in Central Caribbean climate.