Abstract:
Extended salt deposits in a 220,000-year long Dead Sea sediment core, mark episodes of
extreme aridity during interglacials (MIS 7, MIS 5, and the Holocene). These intervals coincide
with maxima in Northern Hemisphere fall precession and with intensified North Atlantic
latitudinal SST gradients in transient simulations. The enhanced gradient drives a poleward shift
of the winter jet and storm track, increasing subtropical sea-level pressure and reducing
Mediterranean rainfall. Similar SST gradient strengthenings occur during deglaciations—
associated with ice-sheet meltwater input, which produces comparable atmospheric responses.
CMIP6 simulations under historical and future greenhouse forcing show a related linkage
between the North Atlantic SST gradient and eastern Mediterranean winter rainfall, suggesting
this mechanism helps explain inter-model differences in projected precipitation change.