Ground level evaporation during the dry period concentrated calcium in salty surface water flowing into the caves. (newscientist.com)
A component of this transport is tied to a current system where salty surface water near the Arctic loses heat, becomes denser, and thus sinks into the deep ocean. (realclimate.org)
Temperature and salinity of shelf waters fluctuate seasonally (from 10 to 29 °C and from 33.0 to 36.5 psu), whereas warm and salty surface Gulf Stream waters are much less variable. (journals.plos.org)