Inferring moisture transport across Central America: Can modern analogs of climate variability help reconcile paleosalinity records?

The interpretation of sea-surface paleosalinity reconstructions from the eastern tropical Pacific in terms of Atlantic-to-Pacific moisture transport is revisited. It is argued that the use of modern analogs of interannual climate variability may help to reconcile seemingly contradictory results from paleosalinity reconstructions at different locations in the east Pacific. For the Last Glacial Maximum, the pattern of tropical east Pacific paleosalinity suggests that the Atlantic-to-Pacific moisture export was similar to today’s, while the wind field was probably biased towards El Niño-like conditions in that region. A La Niña analog for Heinrich Stadial 1 leads to the conclusion that the Atlantic-to-Pacific vapor transport was reduced during times of thermohaline circulation slowdown. It is further argued that the modern seasonal cycle is not a useful analog for longer-term hydroclimatic variability in the tropical Pacific–Atlantic region.